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1. 2 1 3 Products offered Dy SWISSIODO arise EE et du e 2 1 4 Products 0 7 ered bysSwissphoto AG x ama u esc ee 2 1 4 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING II PRE PROCESSING 1 General 1 1 Requirement The main purpose of the pre processing activities is to define the project and the different scenarios to prepare the available topographic input data and to put it in the format needed by the computational module as shown in the overview in part of the User Manual Additionally the choice of computational approaches and boundary initial conditions has to be made 1 1 1 Project Scenarios A project is defined for one region which is to be analyzed Within a project one or more scenarios can be embedded To manage a project it is therefore necessary to define which scenarios files and other elements belong to it This includes the information where all these elements are stored and how they are connected to each other For the same project several scenarios can be created For each of them a simulation 15 executed The different scenarios can vary regarding the computational mesh other input data the used approaches and the boundary conditions In addition type location and time of the results to save have to be specified The simulation can be done in 1 2 or 3 dimensional computation or as a combination of t
2. mesh generated SMS for section the widening part The bold black lies are break ines JOT the mesh a iene REN QE UG RE S E 3 2 1 Fig 15 Material indexes Ids used for assignment the friction factor 3 2 2 Fig l6 Node id numbers for the definition in the STRING DEF block for the inflow boundary 3 3 4 Fig 17 Node id numbers for the definition in the STRING DEF block for the outflow boundary 3 3 4 Fig l6 Stationary hydrograph file saved as Inflow stationary txt 3 3 6 Fig 19 Steady inflow hydrograph and outflow hydrograph 3 4 1 Fig 20 Flow depth and flow velocity vectors at the steady state of the model 3 4 2 Fig 21 Hydrograph of the flood event of July 2004 3 4 3 Fig 22 Inflow hydrograph stored in the file Inflow instationary txt Note that the points are just illustrative in order to show the first and last line of the file 3 4 4 Fig 23 Maximal flow depth and flow velocity vectors of the unsteady flow simulation 3 4 6 Fig 24 Modeled bed elevation z bed and two cross sections defined in the widening part 3 6 1 VAW ETH Z rich U IV iii Version 12 16 2010 User Manual BASEMENT TUTORIALS Fig
3. 6 3 1 Explicit coupling of sub domains a 6 3 1 6 3 1 One way coupling and two way coupling 6 3 1 6 4 Definitions of Exchange Conditions 6 4 1 6 4 1 General remmalk5 osea ues duda doen u itaas um kala 6 4 1 6 4 2 Exchange conditions for mixed dimensional sub domains 6 4 2 6 4 3 Exchange conditions for river junctions 1 D river networks 6 4 2 6 4 4 Exchange conditions for river bifurcations 1 D river networks 6 4 3 6 4 5 Exchange conditions for combined 1 D and 2 D modelling 6 4 4 6 4 6 Data exchange for morphological simulations with multiple grain classes 6 4 5 6 5 Synchronization Concept u 6 5 1 6 5 1 General remarks on synchronization 6 5 1 6 5 2 Local time stepping approach 6 5 1 66 External Coupling u u Z olei PEE a 6 6 1 6 6 1 IH OG UOM uyan 6 6 1 6 6 2 Data exchange over TCP IP 6 6 2 7 Flow Control in R
4. u 3 7 6 34 154 Delme Ne OUMU usse 3 7 7 ii VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 8 Perform morphological simulation with multi grain bed load transport 3 8 9 List of Figures Fred View Of Ne SUNUIGIC Ver SCCHON quyu aka aq Sai Quam Su am Sa 2 1 1 Fig 2 Cross section points inserted in the topography editor 2 252 Delutalion or CFOSS SCCIION ZONES un EH e E E E te EN usi dI E 2 2 3 Pug Declaran Of 2 2 6 Fig 5 Dehlinitionof non flowing epa 2 2 7 Fig 6 Longitudinal profile RAE 2 4 2 Fig 7 Hydrograph of the flood event of u aaa qia QS ahipa aa 2 4 3 Fig 8 Longitudinal profile for maximum discharge 2 4 5 Fig 9 Example of resulting water surface elevation a 2 4 6 Fio SSouUassuument an the user Inter ACC iua ua m dE TR RINT eaten ERR UR METUO eU 2 5 2 Fig 11 Longitudinal profile of mean bottom 2 6 1 Tiad CROSS SECON REUS QUARE 2 6 1 Fig 13 Different morphological river subsections of the new section of the river Flaz 3 1 1 Fig 14
5. 3 4 1 3 4 1 Delaunay triangulation and constrained Delaunay trianoulation 3 4 1 3 4 2 A uM A ME E A MO AEAEE 3 4 3 3 5 Use of the grid generator of SMS 10 3 5 1 VAW ETH Z rich U II i Version 10 22 2009 User Manual BASEMENT PRE PROCESSING Fig Fig Fig Fig Fig Fig Fig Fig Fig Tab Tab Tab U Il ii x WU eub Ie s List of Figures Visualization of the vertical setup for a computational cell within the models 2 3 1 Unstructured grid Triangulation 223 etu n boda tpa t tcu Nec eae 3 1 1 Left ambiguous quadrilateral element with false break line right correct discretisation of le ICICI SIS LM EE UL es M 3 3 2 Empty circle criterion satisfied b Empty circle criterion not satisfied 3 4 1 a edge circle criterion b empty circle criterion a 3 4 2 a triangulated half planes b merged triangulation 3 4 3 a point insertion and determination of affected triangles b new triangulation 3 4 4 a insertion of the new point b edge swapping based on empty circle criterion 3 4 4 Simulation procedure with use of SMS eer uas 3 5 3 List of Tables Accuracy of current measurement methods
6. 1 3 1 1 3 1 Processed Data TVDOS inta eto Gi vous ES 1 3 1 1 3 2 C AIMS S rera Met MEM ENS 1 3 1 2 System Overview 2 1 Numerical Subsystems acoso din ree vue ta ved xo d ado roov gae cav a aa USNA ego eds 2 1 1 3 Components 3 1 Mathematical Physical Modules 3 1 1 32 Computational uu u u t Ex he ct xo ade poet Ee ect aguas 3 2 1 3 2 1 The Meta Model ME CLIP MU E E E 3 2 1 3 2 2 BASEchain one dimensional model 3 2 3 3 2 3 BASEplane two dimensional model 3 2 4 4 Simulation Procedure 41 Flow of main activities s 4 1 1 42 Scehario Examples u uuu aus 4 2 1 4 2 1 Sediment balance in a river 1 D 4 2 2 42 2 Food Du 22D urna pete uysal aiu e osa IU 4 2 3 42 9 Debis TOW 2 D dads 4 2 3 43 Executing BASEMENT U U u u u u 4 3 1 4 3 1 Executing BASEMENT with graphical user interface 4 3 1 4 3 2 Executing BASEMENT on Microsoft Windows 4 3 1 4 3 3 Executing BASEMENT on Linux e
7. results i 4 f f Fig 7 Activity diagram Sediment balance in a river U 4 2 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 4 2 2 Flood 1 D 2 D import topography of b A generate 2d regions y computational mesh amp y EIE domain import or enter cross sections perform b specify boundary conditions for add properties to Simulation each computation region J mesh elements Y elaborate gt represent results E results y Fig 8 Activity diagram Flood 1 D 2 4 2 3 Debris flow 2 D Import 4 generate D add caracteristics e gt lt topography computational mesh y to grid elements specifydebrisflow specify specifyinlet parameters approach hydrograph perform elaborate represent simulation results 7 A results Pus s s i Fig 9 Activity diagram Debris flow 2 D VAW ETH Zurich Ul 4 2 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 4 2 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 43 Executing BASEMENT 4 3 1 Executing BASEMENT with graphical user interface GUI The start and execut
8. called OpenMP Open Multi Processing was developed which is today the de facto standard for parallelizing scientific and engineering applications on shared memory systems OpenMP is used for the parallelization of BASEMENT 5 3 2 Characteristics of OpenMP OpenMP consists of a set of compiler directives and library functions With these compiler directives the developer describes the parallelism in the code Therefore a compiler is needed which supports these OpenMP directives OpenMP is currently supported by many and Fortran compilers on a variety of platforms In the table below some aspects pro and contra parallelization with OpenMP are listed see also Kuhn for a comparison of OpenMP and threading in C C No full control over the implementation details is possible Bugs in libraries can be difficult to isolate First successes in parallelization relatively easy achieve Compiler directives reduce the needed programming efforts and implementation details are left to the compiler Rather small increases in the size of the source code due to the use of compiler directives Good readability of the code is maintained and the algorithms are not buried by large blocks of added parallelization instructions Compiler generated code portions and library calls can complicate debugging of the parallel program OpenMP is standardized and portable on different platforms VAW ETH Z rich Version 7 8 2011 Op
9. m Arithmetic mean grain size according to Meyer Peter amp M ller F U G U Flux vectors F N Force g m s Gravity h m Water depth flow depth h m Thickness of active layer K m s Conveyance factor K k AR k m s Strickler factor mm equivalent roughness height m kg Mass n m s Normal directed outward unit flow vector of a computational cell ng Total number of grain size classes M Ns Momentum P N m Pressure F m Hydraulic Perimeter p Porosity Ps Porosity of bed material in active layer Pow Porosity of bed material in sub layer O m s otream or surface discharge Q m s total bed load flux for cross section 4 m s m total bed load flux of grain size class g per unit width Ip x dp m s m Cartesian components of total bed load flux Tp gt yy m s m Cartesian comp of bed load flux due to stream forces Tp 55 TB m s m Cartesian comp of lateral bed load flux q m s Specific lateral discharge discharge per meter of length R m Hydraulic radius S U Vector of source terms 5 Friction slope Bed slope m s suspended load source per cell and grain size class Sf m s active layer floor source per cell and grain size class VAW ETH Z rich 1 Version 4 23 2007 System Manuals BASEMENT A 3 2 m s 5 m s m s m s m s m s m s m m m
10. yes 1000 TUTORIALS VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 8 Perform morphological simulation with multi grain bed load transport Open the command file Flaz morphology_multi_grain bmc either by double clicking or via the menu in BASEMENT File gt Open Command Run the simulation with the Run button in the BASEMENT window Be aware that the mesh command file and all other input files have to be in the same folder The defined outputs are now stored in the same folder as the command lile The morphological changes deltaz are shown in Fig 27 Here the multi grain model is not compared quantitatively with the single grain model Nevertheless the qualitative comparison Is indicating a quite similar behaviour Fig 26 and Fig 27 At this state much more details could be investigated such as the grain class fractions the hiding and exposure function hiding exponent the amount of grain classes etc Further important calibration parameters are the critical dimensional shear stress the bed load factor and the bed load inflow controlled with the bed load factor at the boundary deltaz m 1 2 1 0 8 0 6 0 4 0 2 0 0 2 0 4 0 6 0 8 1 1 2 Fig 27 Changes of the morphology deltaz due to the flood event with the multi grain model The red colour range represents deposition and the blue colour range shows erosion VAW ETH Zurich U IV 3 8 9 Version 12 16 2010 User Manual BASEMENT
11. This page has been intentionally left blank U Il 2 2 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 2 3 Characteristic quantities of riverbed The numerical models used for the computation of hydraulic behaviour are always declared to be either 1d flow direction of main flux x axis and or 2d horizontal depth averaged flow field However the fundamental terrain topography is always three dimensional The Spatial discretization of the transport equations is based in 1d on cross sections or in 2d on an unstructured grid of mostly triangles The vertical component consists of different layers separated by a planar joint face for both 1d and 2d simulations Vertikaler Aufbau einer Berechnungszelle Idealisierung anhand gemittelter Kennwerte i z Wasserspiegellage uivalente Sandrauheit Oberflachenbeschaffenheit Tb crit surface kritische Sohlschubspannung Oberfl chenbeschaffenheit Sohlkote granulometrische Zusammensetzung des Materials in Austausschicht Ausgangs Zusammensetzung py 4 ranulometrische Zusammensetzung des 51 Materials in Unterschicht S1 UK Unterschicht S1 ranulometrische Zusammensetzung des Bk S J Materials in Unterschicht S UK Unterschicht S z ranulometrische Zusammensetzung des Bk Sn Materials in Unterschicht Sn UK Unterschicht Sn OK Fels nicht erodierbarer Untergrund y ref x Fig 1 Visualization
12. bedload transport multi bedload factor 0 5 limit bedload wetted off lateral transport on lateral transport factor 1 0 3 7 1 7 Define the output The desired output of the simulation has to be defined explicitly in the OUTPUT block The specific output is defined in the repeatable SPECIAL OUTPUT blocks For the multi grain simulation some additional output may be interesting such as for example the grain size distribution in selected nodes This way grain sorting effects can be observed A detailed overview of all possible output types values format types and more is given in help buttons in the Command File Editor of BASEMENT OUTPUT output time step 2000 console time step 100 SPECIAL OUTPUT format sms type node centered values depth deltaz z node output time step 10000 SPECTAL OUTPUT format tecplot binary yes type element centered values z element deltaz output time step 80000 VAW Z rich U IV 3 7 7 Version 12 16 2010 User Manual BASEMENT U IV 3 7 8 SPECIAL OUTPUT type balance balance values sediment timestep output time step SPECIAL OUTPUT 5000 type node history node values grain size node ids 814 4758 9312 history one file output time step SPECIAL OUTPUT 5000 type boundary history boundary values history one file output time step Q Qsed
13. geometry of cross sections and their location XorigsYorig computational partition basic numerical information based on original partition edge with fluxes between two elements control volumes Fig 4 Discrete Representation of the Topography within BASEchain In one dimension an element consists of two nodes with known cross section With a cell centred discretization all variables velocity flow depth and cross section geometry are defined at the location of the nodes The midpoint of the connecting line between two nodes defines the common edge of the two elements The more nodes are known the better the representation of the real world data especially at regions with strongly curved watercourse VAW ETH Zurich U 3 2 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 3 2 0 BASEplane two dimensional model Discrete Representation 2d Overview original grid basic geometrical information based on triangulation w triangle node Xorig Yorig Zorigl connection between 2 triangle nodes e triangle centroid x y z computational grid basic numerical information based on triangulation and interpolation edge with fluxes h hu hv between two elements control volumes Fig 5 Discrete Representation of the Topography within BASEplane In two dimensions an element consists of three nodes with a known ground elevation Usually this real world height inform
14. mixture inflow fractron e 45 15 23 2750 DO mixture roughness elements fraction 17 11 14 27 14 17 mixture widening Traction CY 21 32 16 25 39 mixture alt bars fraction 27 14 14 20 14 11 3 7 1 4 Define the soil composition The soil layers with the corresponding sediment mixture are defined in the SOIL_DEF block The soil can be defined with several layers of different material but to keep it simple we assume a single layer The negative bottom elevation defines the thickness of the layer Below the last layer a fixed bed is assumed If no LAYER block is defined then automatically a fixed bed on the surface is assumed We use this especially for the river bed near the upper boundary condition to avoid uncontrolled erosion Furthermore the embankments are kept fix because the main focus is on set on the river bed morphology The two soils soil fix 20 and soil fix 40 are defined to have a gradual transition from the fixed bed to the movable bed U IV 3 7 4 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS SOIL DEF name soil roughness elements LAYER bottom elevation 0 8 fixed bed 0 8 m below the surface mixture mixture roughness elements j j SOIL DEF name soil widening LAYER bottom elevation 2 0 fixed bed 2 0 m below the surface mixture mixture widening SOIL DEF name soil alt bars LAYER bottom elevation 2 0 fixed bed 2 0
15. Faeh R Mueller R Rousselot P Vetsch D Volz C Vonwiller L Veprek R Farshi D 2006 2011 VAW ETH Zurich Version 8 19 2011 System Manuals of BASEMENT CREDITS Citation Advice For System Manuals Faeh R Mueller R Rousselot P Vetsch D Volz C Vonwiller L Veprek R Farshi D 2011 System Manuals of BASEMENT Version 2 1 Laboratory of Hydraulics Glaciology and Hydrology VAW ETH Zurich Available from http www basement ethz ch date of access For Website BASEMENT Basic Simulation Environment for Computation of Environmental Flow and Natural Hazard Simulation 2011 http www basement ethz ch For Software BASEMENT Basic Simulation Environment for Computation of Environmental Flow and Natural Hazard Simulation Version 2 2 VAW ETH Zurich Faeh R Mueller R Rousselot P Vetsch D Volz C Vonwiller L Veprek R Farshi D 2006 2011 VAW ETH Zurich Version 7 6 2011 System Manuals of BASEMENT PREFACE Preface to Versions 1 0 1 3 The development of computer programs for solving demanding hydraulic or hydrological problems has an almost thirty year tradition at VAW Many projects have been carried out with the application of home made numerical codes and were successfully finished The according software development and its applications were primarily promoted by the individual initiative of scientific associates of VAW and financed by federal instances or t
16. SYSTEM MANUALS of BASEMENT System Manuals BASEMENT This page has been intentionally left blank VAW ETH Zurich System Manuals of BASEMENT CREDITS VERSION 2 2 August 2011 Project Team Prof Dr R Boes Committee Member of Project Integrales Flussgebietsmanagement Director VAW Dr R Fah Dipl Ing ETH Committee Member of Project Integrales Flussgebietsmanagement Scientific Supervisor R M ller Dipl Ing EPFL Software Development Scientific Associate P Rousselot Dipl Rech Wiss ETH Software Development Scientific Associate C Volz Dipl Ing Software Development Scientific Associate L Vonwiller MSc ETH Documentation and Test Scientific Associate D Vetsch Dipl Ing ETH Project Supervisor Scientific Associate Art Design and Layout W Thurig D Vetsch Former Project Members em Prof Dr Ing H E Minor Member of the steering committee of Rhone Thur Project 2002 2007 Director of VAW 1998 2008 Dr R Veprek Dipl Rech Wiss ETH Software Development Sc Associate 2009 2010 Dr Ing D Farshi MSc Software Development Scientific Associate 2002 2007 Commissioned and co financed by Swiss Federal Office for the Environment FOEN Contact basement ethz ch htto www basement ethz ch Laboratory of Hydraulics Eidgenossische Technische Hochschule Zirich Hydrology and Glaciology Swiss Federal Institute of Technology Zurich ETH Zurich VAW
17. 3 5 1 2 Bed material a a 3 5 2 3 5 1 3 Grain Size distl IDELIOFI 25 ads uu u A total os te uds a 3 5 2 3 5 1 4 CAI Erbe Cs rassaa e a qas 3 5 3 3 5 1 5 Define the soil composition 3 5 3 3 5 1 6 Fixed ped elevation g ns u uu unun kas 3 5 4 9 59 1 7 Assignment of the defined soil 3 5 5 3 5 1 8 Hal CONGWION y uw hee D 9 959 3 5 1 9 Bed load boundary condition 3 5 5 39 110 Bed load parameter saranin es paqu aq 3 5 6 9o Td SGOT3WIIaliopalilrallepoO0ruu u kuy u Spr yat Iur Fuer nove Red rots 3 5 6 392 Dene TNS OUNOU u uuu unn uuu EE 3 5 8 3 6 Perform morphological simulation with single grain bed load transport 3 6 1 3 Morphological simulation with multi grain bed load transport 3 7 3 3 7 1 1 Morphological parameters 3 7 3 3 7 1 2 size distriDULlOD m soe elo 3 7 3 3 7 1 3 fice TE 3 7 4 3 7 1 4 Deline tae SOMCOMPOSIION 3 7 4 3 7 1 5 Bed load boundary condition 3 7 6 3 7 1 6 Bed load pal ameter ustus suu kuupa hu hua
18. 95 73 60 CROSS SECTION P7380 95 73 80 CROSS SECTION P7400 95 74 00 or 24 20 Fig 6 Grid File Editor Cross Section View Input Structure Validation Messages For details on how to set up a new cross section and for information about the various cross section parameters see the 1 D tutorial in the manual UIV VAW ETH Z rich U Ill 4 2 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE This page has been intentionally left blank U Ill 4 2 2 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 4 3 Tools BASEMENT supports several tools which support the user in creating and modifying the 1D grid file In the following sections some information about the usage and the methods of these tools are given Please be aware that some of the offered tools are still in a beta status 4 3 1 Edit Raw Another way to edit a grid file is to edit the grid file in raw text mode For this purpose choose Tools on the menu bar and select Edit Haw The Editor window will pop up as shown in Fig Fig 4 In the lower part of the window the Input is validated and possible parse errors are indicated For the sake of completeness it is mentioned here that the grid file can still be built up and edited with a simple text editor BASEMENT v2 334 079 419 773 bottom_range 167 807 243 755 SOIL_DEF index
19. D Rhein Kalib km50 9559 Geo95km50 95 bmg BASEMENT 1D grid file editor BAX File Tools Input Structure M CROSS SECTION 163 BASECHAIN_GEOMETRY CROSS SECTION P50000 95 50 000 New Tags Blocks l CROSS SECTION 5000 95 50 200 CROSS SECTION 5000 95 50 400 1 available v CROSS SECTION PS0200_95 50 200 CROSS SECTION P50400 95 50 400 E CROSS SECTION P50600 95 50 600 Add Tag ae a CROSS SECTION PS0800_95 50 800 CROSS SECTION PS1000_95 51 000 CROSS SECTION P51200_95 51 200 CROSS SECTION PS1400_95 51 400 CROSS SECTION PS1600_95 51 600 CROSS SECTION PS1800_95 51 800 CROSS SECTION PS2000_95 52 000 CROSS SECTION PS2200_95 52 200 CROSS SECTION PS2400_95 52 400 CROSS SECTION PS2600_95 52 600 CROSS SECTION PS2800_95 52 800 CROSS SECTION PS3000_95 53 000 CROSS SECTION PS3200_95 53 200 CROSS SECTION P53400_95 53 400 CROSS SECTION P53600 95 53 600 CROSS SECTION P53800 95 53 800 CROSS SECTION P54000 95 54 000 CROSS SECTION P54200 95 54 200 CROSS SECTION P54272 95 54 272 CROSS SECTION P54400 95 54 400 CROSS SECTION P54600 95 54 600 CROSS SECTION P54800 95 54 800 CROSS SECTION P55000 95 55 000 CROSS SECTION P55200 95 55 200 CROSS SECTION P55400 95 55 400 CROSS SECTION P55600 95 55 600 CROSS SECTION P55800 95 55 800 CROSS SECTION P56000 95 56 000 CRO
20. Faeh E Mueller E Rousselot P Veprek R Vetsch D Volz C Vonwiller L Farshi D Fig 1 BASEMENT Main Window with menu bar action buttons splash screen and a progress bar The menu File allows for opening either an existing command file Open Command or an existing 1 D Grid Open 1D Grid within the BASEMENT Editor Selecting Quit from the File menu will exit the Application The menu Options hosts the setting for the Log level Different Log levels are available A Log level 5 will show all possible Log output whereas Log level 0 will suppress most of the Log information from the application VAW ETH Z rich U Ill 2 1 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE The splash screen can be shown anytime again by selecting About BASEMENT from the Help menu The action buttons have the following behavior e Edit Command opens the currently active Command File within the Command File Editor If no Command File has been opened yet the Editor will be empty A description of the Command File Editor is given in chapter 3 e Edit 1D Grid opens the currently active 1D Grid definition within the 1 D Grid File Editor If no 1 D Grid has been opened yet the Editor will be empty A description of the 1 D Grid File Editor is given in chapter 0 e Runis only active when a Command File is active in the background Pressing this button will start a simulation according to the settings in the Command File e
21. coverage A high coverage is of importance because the negative impacts of remaining serial parts in the code increase aS more and more cores are employed The achievable speedup finally becomes limited by these serial parts see Amdahl s law Chandra Load balance The overall execution time of a parallel loop is determined by the thread with the slowest execution time If the work load is not properly balanced between the multiple threads performance will suffer A good approach for parallelizing a loop often is a simple static scheduling which means that all iterations are divided in parts of equal size before the threads start execution But in case that the computational costs of the iterations differ largely a static scheduling may not be optimal E g in 2 D simulations with dry and wet regions the flow equations must only be solved entirely for the wet or transitional elements but not for the dry elements Beside the problem of moving boundaries of the wetted domains it is also important to note that hydrodynamic models may lead to imbalanced load distributions in case of local highly unsteady processes like wave propagations The load balance can sometimes be optimized in such cases by the use of dynamic scheduling which divides the work load dynamically among the threads Threads with computational cheap iterations will dynamically receive additional iterations thereby taking load from threads with costly iterations Dynami
22. f11 417 376 6644 12 570 376 2211 14 532 376 21 17 099 375 99 Fig 4 Definition of cross section properties 2 2 3 Friction values For the friction determination the Strickler approach is used This is declared in the command file by setting the type in the FRICTION block within the HYDRAULICS section to Strickler In this case Strickler k values have to be defined for the different regions The banks of the main channel are partially covered with small bushes The flood plains are covered with grass stones and sand but there are also zones with trees U IV 2 2 4 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS The following Kg values are used e Banks of main channel ka 35 m s e Flood plains ka 33 m s For the bed bottom the following transformation based on the grain characteristics of the sediment is used 490 5 cm 23 In BASEMENT internally the cross section is represented by slices defined by the segment between two nodes Each slice has its own properties Therefore we have to provide so called ranges to assign the friction values to the respective slices The ranges can be defined either referring to node coordinates note that you have to match the coordinates exactly or by referring to slice indexes starting at index 1 from left to right Bottom k 38 m s 2 2 4 Computation of water surface elevation As it is much quicker the u
23. uncontrolled erosion Furthermore the embankments are kept fixed because the main focus is on the river bed morphology The two soils soil fix 20 and soil fix 40 are defined to have a gradual transition from the fixed bed to the movable bed Anyway the river section with the roughness elements cannot be modelled accurately because single roughness elements which are more or less fixed stones cannot be discretized within the computational mesh They have to be modelled with an increased bed roughness instead SOIL DEF name soil roughness elements LAYER bottom elevation 0 8 fixed bed 0 8 m below the surface mixture single grain SOIL DEF name soil widening LAYER bottom elevation 2 0 fixed bed 2 0 m below the surface mixture single grain VAW ETH Z rich U IV 3 5 3 Version 12 16 2010 User Manual BASEMENT TUTORIALS SOIL DEF name soil alt bars LAYER bottom elevation 2 0 fixed bed 2 0 m below the surface mixture single grain SOIL DEF name soil fix 20 LAYER bottom elevation 0 2 fixed bed 0 2 m below the surface mixture single grain SOIL DEF name soil fix 40 LAYER bottom elevation 0 4 fixed bed 0 4 m below the surface mixture single grain SOIL DEF name soil fix fixed bed 3 5 1 6 Fixed bed elevation There are several possibilities to define a fixed bed In the FIXED BED block the elevations of areas with
24. 15 20 forest insecure 3 Radar InSAR _ open lea 20 cmi3 E Tab I Accuracy of current measurement methods 1 Gewdssergeometrie Landesanstalt fiir Umweltschutz Baden Wiirttemberg Karlsruhe 1999 2 Swissphoto AG verbal 3 Leitfaden Qualitdtssicherung Photogrammetrie und DTM Generierung Konferenz der Kantonalen Vermessungsdmter 2000 4 GPS global positioning System swisstopo The products which are directly available in Switzerland and their accuracies are listed in the following tables VAW ETH Zurich U Il 2 1 3 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING Product Density Source Format Accuracy DHM25 35 1600 point km 1 25000 map Arc View Mean error Base Model DIM vectorized contour lines and Shape Files To to 3 contour lines in lakes lake DXF GEN meters perimeters and spot heights BMBLT depending on main break lines the regions photogrammetric data DHM25 1600 points km interpolation of the Base Model MMBLT Matrix Model DTM on a 25x25m orid MMBL AIGRID XYZ DXF VRML DTM AV raw 1 point for 2 m based on official measurement ASCII height with Lidar Airborne Laser Interlis accuracy Scanning others 50 cm possible requested DTM AV grid2 2x2m grid interpolated from DIM AV raw DSM AV raw 1 point NEN 2 m with buildings and vegetation ASCII height Interlis accuracy others 50 cm possible if 150cm_ for requested vegetati
25. 2 3 3 3 apuman 3 3 2 3234 FhysicalDbroperlieg k uuu nu uuu h aaa 3 3 2 9 29 5 fwo dimensional SIMULATION uuu cde dentato coacta 3 3 3 3 5 1 CGGOITIS PV auqa 3 3 3 3411 D fine the NydraulCS uuu uuu uu u s uyu S Sui e rwr cave das 3 3 5 3 3 5 1 2 Hydraulic boundary conditions 3 3 5 9 352159 Imnilial 6ondilioi aa cp 3 3 6 S 35 14 3 3 6 3 3 5 1 5 Computational parameters uuu uuu w Ous uuu uy basa 3 3 7 3 3 5 2 elime e OLD aded eee tex ted coda odas ume GU Gta 3 9 7 3 4 Perform hydraulic simulation J J 3 4 1 3 4 1 Perform steady flow simulation 3 4 1 3 4 2 Perform unsteady flow simulation 3 4 2 3 4 3 Calibration of the hydraulic model 3 4 6 3 5 Morphological simulation with single grain bed load transport 3 5 1 3 5 1 Define the morphological information 3 5 1 3 5 1 1 Morphological n 3 5 2
26. 2 5 cm In the topography file the codes of the different types are assigned to different cross sections The code can be set in the cross sections by creating a new sub block SOIL DEF where the index is set to the respective soil index in the command file and the span of the soil is defined via the range it extends SOR DEF New Tags Blocks 1 available index 2 80 146 194 330 Fig 4 Declaration of soil types U IV 2 2 6 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 2 6 Define flowing zones The 1 D model considers the flow velocity to be the same over the whole width of the cross section This is obviously not true especially for cross sections where important zones are behind a sort of dike like it occurs very often at the Thur This effect has an important influence on the bed load transport For this reason regions where the water does not flow are declared using the water_flow_range tag The next figure shows an example of a cross section with the different zones Of course we only mention this here The tutorial topology already contains the required ranges cross section 10 378 377 378 375 374 373 372 371 not flowing area yim Fig 5 Definition of non flowing areas VAW ETH Z rich U IV 2 2 7 Version 12 16 2010 User Manual BASEMENT TUTORIALS This page has been intentionally left blank U IV 2 2 8 VAW ETH Z rich Versi
27. 25 Comparison of the river bed before and after the flood event in cross section QS I and QS akka kasha ah apna 3 6 2 Fig 26 Changes of the morphology deltaz due to the flood event with the single grain model The red colour range represents deposition and the blue colour range shows erosion 3 6 2 Fig 27 Changes of the morphology deltaz due to the flood event with the multi grain model The red colour range represents deposition and the blue colour range shows erosion 3 8 9 U IV iv VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS IV TUTORIALS 1 General The tutorials of BASEMENT provide a step by step introduction to numerical modelling Therefore all necessary parts of the simulation procedure such as setting up the topography or defining the simulation s command file are described in detail herein This part of the system manuals lives with your feedback Please don t hesitate to submit further examples which you think could be of interest for other users Also feel free to let us know what you miss and would like to study in the next version of the tutorials Please use the official BASEMENT email basement 9ethz ch therefore Many thanks for your collaboration VAW ETH Z rich U IV 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS This page has been intentionally left blank UIV 2 VAW ETH Zurich Version 12 16 2010 User Manual BAS
28. 4 1 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 4 2 Create New or Edit Existing Geometry File If a specific cross section is selected or a new cross section is created than a profile view of the selected cross section is shown see Fig 6 With this visualization of the profile one can easily check for input errors in the geometrical definition of the cross section profile Furthermore the most important cross section parameters are indicated visually with different colours like e g the definition of the main channel the range of the soils the friction parameters the cross section fixpoints etc Again one can visually check if these parameters are set up correctly and thus easily detect type errors New input tags can be added and the validation message box shows warnings or errors if some problematic inputs have been made A D BASEMENT simtests test chain Rhein run RheinTopo txt bmg BASEMENT 1D grid file editor Jog File Tools Input Structure A 1 ri E BASECHAIN_GEOMETRY amp B CROSS SECTION 6560_ 65 20 New Tags Blocks CROSS SECTION P6560 b 65 40 CROSS SECTION P6560 95 65 60 1 available v CROSS SECTION 580_95 65 80 CROSS SECTION P6600 95 66 00 _ E CROSS SECTION P6620_95 66 20 acd log 16 available a CROSS SECTION P6640_95 66 40 CROSS SECTION P6665_9
29. 4 2 3 Fig 10 Shared memory architectures left and distributed memory architectures right 5 1 2 Fig 11 illustration of different levels Of parallelism 5 2 1 Fig 12 Compiler directives for basic parallelization constructs OpenMP 5 3 2 Fig 13 Critical sections and barriers for synchronization operations in 5 3 3 Fig 14 River network with multiple BASEchain 1 0 and BASEplane 2 0 sub domains and several Countine 6 1 1 Fig 15 Modeling of a river junction with two different approaches black arrows indicate a confluence of river branches red arrows a bifurcation 6 4 3 Fig l6 Conceptual overview of combined 1 D river flow and 2 D floodplain modeling 6 4 4 Fig 17 Mapping of grain compositions from one sub domain to another 6 4 6 Fig 18 LTS synchronization for 3 sub domains with different time step sizes The sub domain C with the smallest time step size determines the base time step Sub domains A and B run for multiples of 4 and 2 of the base time step size 6 5 2 Fig 19 Connection request from external program client to BASEMENT server 6 6 2 Fig 20 Sending
30. 4 2 Create New or Edit Existing Geometry File 4 2 1 4 3 TOOLS me cei a I IUD LEE I M I 4 3 1 4 3 1 Edit AW ert TT Mm 4 3 1 432 ACUO mE Tm 4 3 1 49 Remove Nodes nodus a a menu cu IR ERU 4 3 2 GUESSACIVE RANJE 0 Lm 4 3 3 4 3 4 Fixpoints nnn 4 3 3 42595 1556 asas 4 3 4 4 3 6 Export DTM for BASEplane a 4 3 7 5 Built In GUI Tools 5 1 Interactive Visualization during run time using BASEwviz 5 1 1 5 2 Manual Controller Interface HID J T T J 5 2 1 VAW ETH Z rich U IIl i Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig Fig U III List of Figures 1 BASEMENT Main Window with menu bar action buttons splash screen and a progress 2 1 1 2 Main Structure the BASEMENT Command File Editor 2 2 1 3 BASEMENT Command File Laior t rtis m 3 1 1 4 Command File Editor Raw Edit Window 3 3 1 SP Grid File Editor Subdomain i u G e a ge au a pn au
31. 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT To ease the distribution of work load among the threads of a parallel region OpenMP supports work sharing constructs which automate such tasks see Fig 12 With optional parameter clauses it is possible for the user to define the behaviour of these compiler directives in more detail A complete OpenMP reference is available online at http www openmp org For special needs it is also possible to share the work load among the threads fully flexible by individually addressing each thread In OpenMP several compiler directives are supported for synchronization issues which cover the most frequent tasks Such constructs are barriers locks critical sections and atomic constructs Beside these standard constructs fully flexible synchronisation operations can be implemented for special tasks using global flags in memory The choice of the best suited constructs for synchronisation and mutual exclusion is problem depended and involves differing efforts in parallel programming synchronization mutual exclusion pragma parallel thread A thread B critical section wait until id thread B has finished J l implict barrier wait until critical section is accesible pragma orrp critical section critical section Fig 13 Critical sections and barriers for synchronization operations in OpenMP Some general parameters controlling the parallelis
32. Bern and Eppstein 1995 other similar definitions existent aspect ratio ratio of the circumference and the in circle of a triangle roughness of the piecewise linear interpolation of a 2 5 D problem The roughness of an interpolated surface can be measured e g by the Sobolev semi norm The criteria which determine the quality of a mesh differ depending on the application respectively partial differential equation and the numerical method implemented Also the possible optimization depends on the constraints given by the original data It Is recommended to avoid L shaped overall areas non convex hull as such problems often lead to numerical instabilities in the concave corner In general a height aspect ratio very small angles and especially very large angles are considered as bad as they lead to a poor numerical condition of matrices and increase the approximation error which arises with the element size in general as well Big differences of size between neighbouring cell elements can have a negative influence on the numeric simulation too VAW ETH Zurich U Il 3 3 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 3 2 Ambiguous gradients A further mesh quality criterion specific to meshes consisting of quadrilateral elements or meshes with mixed element types is the problem of ambiguous gradients Quadrilateral elements are defined by four nodal points These nodes ideally have elevations which guarantee that
33. O ITPUIT BASE vir L OJTRUT rode centered OJTPUT balance SPECIAL OJTPUT boundary history slcpe 13 0 Move Up Down Input Structure Block Error Tag string name s mandatory but missing Validation Messages Fig 2 Main Structure the BASEMENT Command File Editor 2 2 2 Edit Blocks and Tags 2 2 2 1 Add Blocks Select a Block from the Input Structure Use the drop down menu near the Add Block button in the Main View to see all available Blocks Select one of them and press the Add Block button to add a new Block VAW ETH Z rich U Ill 2 2 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 2 2 2 2 Define Tags Select a Block from the Input Structure Use the drop down menu near the Add Tag button in the main view to see all available Tags Select one of them and press the Add Tag button to add a new tag The Tag will appear in the main view and needs to be given a precise value Depending on the Tag a value can be chosen from a drop down menu or has to be defined by the user 2 2 2 3 Remove Blocks or Tags To remove a Block or a Tag use the Delete button as indicated in Fig 2 For a block this is located at the top of the main view near the Blocks name For a Tag the button is to the right of the precise value of a Tag There will be a confirmation message whether a Block or Tag really shall be removed 2 2 3 Automatic Validation Validation Messages indicate immediately whether the curr
34. Tags also includes information about whether it is mandatory default values value range etc U Ill 2 2 2 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT 3 Edit Command File GRAPHICAL USER INTERFACE 3 1 The BASEMENT Command File Editor From the BASEMENT main window Fig 1 the user gets via the Edit Command button to the Command File Editor which is shown in Fig 3 The Input Structure as it is built up with Blocks is on the left hand side The Main View on the right hand side gives more details of the selected Block with the corresponding Tags and the possibility to add Tags and or Blocks see chapter 2 File Tools G D Flaz hydraulic stationary Flaz hydraulic stationary bmc BASEMENT command file editor Input Structure BASEMENT PROJECT E DOMAIN PARALLEL PHYSICAL PROPERTIES S BASEPLANE 2D Flaz GEOMETRY STRINGDEF Inflow STRINGDEF Outflow HYDRAULICS BOUNDARY hqrelation INITIAL FRICTION PARAMETER OUTPUT SPECIAL OUTPUT BASEviz SPECIAL OLITPLIT node centered SPECIAL OUTPUT balance SPECIAL OUTPUT boundary history BOUNDARY New Tags Blocks 10 available type iv iv hydrograph string_name Inflow file Inflow_stationary txt slope 10 0 AJ v E 9 A Y E 9 Fig 3 BASEMENT Command File Editor VAW ETH Z rich Version 12 16 2010 3 1 1 U
35. The 3 dimensional approach is only suitable for local problems where turbulence phenomena and flow in all directions are essential for the results e g the flow around bridge piers Assuming a static pressure distribution and neglecting the vertical flow components the Navier Stokes equations simplify to the 2 dimensional shallow water equations This set of equations provides accurate results for the behaviour of water level and velocities in a plane Turbulence effects cannot be resolved anymore but are accounted for by an artificial friction factor in the closure condition which establishes a relation between flow velocity and shear stress The shallow water equations are used for 2 dimensional flows like dam breaks curved flow etc Reducing the spatial dimension once more results in the 1 D Saint Venant equations The main outputs of these equations are the water level and mean velocity in flow direction This method is still in use for computing large river systems The computation of sediment transport is mathematically not as well developed as the hydrodynamic part Theoretically the movement of every single stone within the sediment could be computed by solving its equation of motion However this approach is yet numerically too expensive Therefore sediment transport and behaviour of the riverbed are computed using empirical formulas developed by river engineers The computation of the sediment flux is physically not really correct
36. This approach bases on the method of local time stepping LTS as presented by Osher and Sanders 1983 and Sanders 2008 But in contrast to these methods LTS is applied here to whole sub domains instead of single grid elements Different local time step sizes are allowed for the sub domains instead of using one global time step for all sub domains This enables efficient computations by preventing very small time steps of single sub domains to dominate the time step sizes of the other sub domains But restrictions are set for the time step sizes in a way to ensure that the sub domains always reach common time levels At these common time levels data can be exchanged easily without the need for interpolations Hierarchical levels L are introduced and attributed to each sub domain These levels categorize the sub domains into groups of common time step sizes These levels are thereby chosen as power of two multiples of the base time step size Af This base time step is selected as the minimum time step size of all coupled sub domains The attribution of VAW ETH Z rich Ul 6 5 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT levels L to a sub domain i depends on the relation of its present time step size to the base time step size and is determined as At gre Sh epi L 2 k 0 n At base where L is the level attributed to the sub domain i k indicates the level and n is the number of levels Each sub domain determ
37. Z rich U IV 3 4 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS Fig 20 Flow depth and flow velocity vectors at the steady state of the model 3 4 2 Perform unsteady flow simulation The unsteady flow simulation is based on the flood event of July 2004 depicted in Fig 21 Compared to the steady flow simulation the command file needs some minor changes First of all the last time step of the steady simulation is taken as initial condition for the unsteady simulation Therefore the file Flaz restart cgns from the steady simulation can be renamed and saved for example as nitial Condition cgns This file now can be used as initial condition for the unsteady flow simulation as follows INITIAL type continue file Initial Condition cgns restart solution time 3000 027 restart start time 0 U IV 3 4 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS With the tag restart_solution_time the solution of the last time step of the stationary simulation is chosen In order to start the simulation from the beginning the restart start time is set to zero Furthermore the inflow hydrograph of the flood has to be defined and assigned to the upper boundary condition The hydrograph of the flood shown in Fig 21 is saved in the text file Inflow instationary txt with contents as depicted in Fig 22 Be aware that the final time defined in this file has to be the same or larger than the computation time The
38. and receiving data from socket stream FIFO pipe 6 6 3 do Af COND OL C VOID siii E a oett eet iet edite e LM as Qam quas 7 2 1 VAW ETH Z rich U I iii Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Tab 1 Tab 2 Tab 3 Tab 4 Tab 5 Tab 6 Tab 7 Ul iv List of Tables OpenMP parallelization pro and contra 5 3 2 Listing of different coupling types and their descriptions 6 2 1 Possible exchange conditions between sub domdains 6 4 1 Exchange conditions for mixed dimensional coupling 1 index of 2 D edge or 2 D Te 1112012 6 4 2 Exchange conditions for river JUNCHIONS 6 4 3 Exchange conditions for river 6 4 4 Exchange conditions for lateral coupling gt 6 4 5 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT I BASIC SIMULATION ENVIRONMENT The software system BASEMENT basic simulation environment shall provide a flexible and functional environment for numerical simulation of alpine rivers and sediment transport involved The numerical models for the computation of one and two dimensional flows with moving boundaries and appro
39. at the coupling cross sections as water levels from upstream and downstream direction may differ for a given time In principle iterations between the sub domains are required and must be performed until the differences of the variables at the coupling cross section do no longer change within subsequent iteration steps Although a rather small number of iterations has to be expected as reported by Miglio Peretto and Saleri 2005 these iterations lead to large additional computational efforts Therefore these iterations are not performed here As the time steps in the explicit approach are usually very small the differences between the upstream and downstream variables are rather small and iterations may be neglected without substantial loss of accuracy But in cases of crucial and abrupt changes in the flow variables oscillations may result A combination of both concepts can be used in the coupled river simulation one way coupled sub domains are executed sequentially from upstream to downstream direction whereas two way coupled sub domains are treated as being a single sub domain within the execution sequence VAW ETH Z rich Ul 6 3 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 6 3 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 4 Definitions of Exchange Conditions 6 4 1 General remarks Data can be exchanged betwee
40. boundaries Inflow outflow boundary 1way coupling 2way coupling Conjunction of sub domains 9 LU i Fig 14 River network with multiple BASEchain 1 BASEplane 2 D sub domains and several coupling interfaces VAW ETH Z rich Ul 6 1 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Some typical applications of coupled simulations are U 1 6 1 2 step wise modeling approach to the overall problem using smaller parts of the whole domain This approach has the advantages of reduced complexity and reduced execution and calibration times Also extensions of existing and calibrated models can be easily made with coupled simulations without the need to redesign the existing models Simulations with hydraulic structures like weirs or gates within the domain of interest can be realized by using multiple sub domains which are coupled via these hydraulic structures Coupled simulations can be helpful for mixed dimensional modeling approaches e g for cases where large scale 1 D simulations shall be combined with detailed modeling of local areas in 2 D Thereby the advantage of efficient and robust modeling in 1 D is combined with the capability to simulate 2 D flow characteristics Also the required efforts for data acquisition and data preparation can be minimized using mixed dimensional modeling approaches VAW ETH Z rich Version 7
41. but proved to be accurate enough for a broad range of sediment transport problems Usually sediment transport occurs in the main flow direction More sophisticated models consider also lateral phenomena within a curved flow Very small grain sizes are treated as suspended sediment load Their behaviour can be computed by a physically scalar transport equation VAW ETH Z rich Ul 3 1 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 3 1 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 3 2 Computational Grid 3 2 1 Meta Model Model Discretization Topography Methodoloc river and DTM cell centred cell vertex interpolated triangulated x cross sections surface Xi B 3 control volumes CV flux over eges local coordinate system Finite Volume Method FVM Grid Topoloc river cross scattered points sections elevation level Structured Unstructured curves river distance national coordinate system Real World Numerical Model Model Fig 3 The Meta Model fusion of real world data with abstract numerical considerations An important aspect of every computational task is the grid generation where the real world topography data is transformed into an internal computational grid on which the governing equations are solved Independent of the discretization method the construction of the
42. could be relevant for debris flows the data could be produced with reasonable costs Until end of 2007 this project shall be finished Swisstopo delivers their terrain data in two formats DTM AV raw a point cloud with averagely 1 point per 2 DIM AV grid2 an interpolated 2x2m mesh The accuracy of position and height is about 0 5 m Additionally swisstopo also works with 1x1m meshes which reach an accuracy below 0 3 m For large areas and a high density of grid points the amount of data is beyond the resources even of nowadays computing power Therefore there exists a variety of algorithms which eliminate all unnecessary points in a certain area that have no influence on the shape of the triangulation This may reduce the amount of data by 10 60 96 U II 2 1 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 2 1 4 Sources and quality of data One main factor for the quality of the results is the accuracy of the original topographic data The accuracy varies depending on the objective of the recording as well as on the recording methods The accuracies of the most diffused methods are listed in Tab 1 Situation accuracy Height accuracy h 2 om 1 Sonic depth finder 5 10 cm 1 gt 10 1 1 3 cm 1 bcm 1 least 4 satellites 1 cm 4 m IEE cm 1 0 2 0 3 of flying altitude 3 cm 2
43. file Thur1 bmc or by loading it as command file in the graphical user interface When the simulation has terminated open the file named restart using a text editor such as notepad If the discharges Q correspond to the steady inflow discharge in all cross sections then the steady state has been reached The restart file can now be used as an initial condition file for the next step Set the time to 0 For this purpose it must be saved as a new text file because the filename it currently has is used in subsequent iterations for the new restart file Therefore save the restart file using the name Initial Thur txt CS41 25 785905 30 CS42 24 429422 30 CS43 22 647555 30 CS44 26 453984 30 CS45 34 367756 30 CS46 35 536409 30 CS4 7 39 03467 30 CS48 38 658572 30 CS49 38 016649 30 CS50 37 518627 30 CS51 34 37052 30 552 47 002793 30 CS53 41 384505 30 CS54 39 940648 30 CS55 31 36507 30 You should also have a look at the file named ThurTopoout txt and verify whether there have been any errors or strange values resulting from your topography file Of course the grid file you have here in the tutorial should not have any errors It s just a good exercise to check your geometry if the program does not work as expected You should also have a look at the main output file to see if there appear suspicious values which could indicate that there is an error somewhere in your model setup Now take from the output file the columns named distance
44. file and necessary strings of nodes Strings are used for inflow and outflow boundaries and can also be used for discharge control The node ids of the inflow and outflow string can be read out from the mesh in Fig 16 and Fig 17 respectively GEOMETRY type sms file Flaz mesh 2dm STRINGDEF name Inflow node Gds 4422 3 abo 7 8939 J j STRINGDEF name Outflow node ids 9478 9479 9499 9500 9501 9519 9533 9546 9552 J VAW ETH Zurich U IV 3 3 3 Version 12 16 2010 User Manual BASEMENT TUTORIALS Fig 17 Node id numbers for the definition in the STRING_DEF block for the outflow boundary U IV 3 3 4 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 3 5 1 1 Define the hydraulics The HYDRAULIC block includes all the information necessary for the hydraulic part of the simulation This block is divided into the following sub blocks HYDRAULICS BOUNDARY NE INITIAL A FRICTION PARAMETER S 3 3 5 1 2 Hydraulic boundary conditions For the upper inflow and lower outflow boundary condition we have to refer to the predefined STRINGDEFs see chapter 3 3 5 1 If the boundary condition is not defined explicitly a wall boundary is considered for those edges Except for the explicitly defined inflow and outflow boundary the model boundary is basically an impermeable wall The inlet boundary condition is defined across the predefined string nflow The hydraul
45. for refinement and coarsening of the mesh 1 5 Tools for control over the mesh quality 1 6 Enumeration tool 1 7 Possibility for geometric intervention 2 Boundary Conditions 2 1 Definition of inflow and outflow stationary and instationary in time 2 2 Definition of discharge directions 2 3 Surfaces of different roughness 3 Computational methods 3 1 stationary and instationary 3 2 wet dry criterion 3 9 computational time The development of a pre processing module had no priority Therefore some commercial products have been evaluated on the mentioned criteria The program SMS 10 Surface Water Modelling System proved to be best suited for all requirements SMS is an overall graphic user interface for mesh generation and manipulation specialized on surface water flows Furthermore it is capable for post processing tasks like visualization of the computed results The program is mainly used for the setup of the computational grid and the definition of boundary conditions VAW ETH Z rich U Il 3 5 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING SMS provides various modules for mesh generation For the use with BASEMENT we recommend the following modules map mesh and scatter modules are contained in the SINGLE MODEL package of SMS as generic model interface price ca 2500 1 Mesh module The mesh module constructs a two dimensional computational grid of rivers bays and ports for whi
46. furnished to do so all subject to the following The copyright notices in the Software and this entire statement including the above license grant this restriction and the following disclaimer must be included in all copies of the Software in whole or in part and all derivative works of the Software unless such copies or derivative works are solely in the form of machine executable object code generated by a source language processor THE SOFTWARE IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE TITLE AND NON INFRINGEMENT IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE FOR ANY DAMAGES OR OTHER LIABILITY WHETHER IN CONTRACT TORT OR OTHERWISE ARISING FROM OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE VAW ETH Z rich Version 7 8 2011 System Manuals of BASEMENT LICENSE AGREEMENT v4 6 Cross platform application and UI framework Copyright C 2010 Nokia Corporation and or its subsidiary ies All rights reserved Contact Nokia Corporation qt info nokia com This library is free software you can redistribute it and or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation either version 2 1 of the License or at your option any later version This library is
47. m INDEX AND GLOSSAR local sediment source per cell and grain size class Time Vector of conserved variables Flow velocity vector with Cartesian components u v w shear stress veleocity Cartesian components of flow velocity vector u Cartesian components of depth averaged flow velocity Cartesian components of flow velocity at bottom Cartesian components of flow velocity at water surface Volume Cartesian coordinate axes Distance in corresponding Cartesian direction Bottom elevation Water surface elevation Elevation of active layer floor VAW ETH Z rich Version 4 23 2007 System Manuals BASEMENT A 4 Greek Symbols Symbol Az SI eds aol oe N N 2 x 2 VAW ETH Z rich Version 4 23 2007 m SS lt lt N Xx T Unit 5 5 5 5 m kg ms m s m s m s m s ko m ko m N m N m N m N m N m m APPENDIX AND INDEX Definition Empirical parameter depending on the dimensionless Shear stress of the mixture volumetric fraction of grain size class g in active layer volumetric fraction of grain size class g in active layer Eddy diffusivity K rm n constant Computational time step Time step for hydraulic sequence Time step for sediment transport sequence Overall sequential time step Grid spacing according to three dimensional Cartesian Coordinate system IR with co
48. m below the surface mixture mixture alt bars SOIL DEF name soil fix fixed bed SOIL DEF name soil fix 20 LAYER bottom elevation 0 2 fixed bed 0 2 m below the surface mixture mixture roughness elements VAW Z rich U IV 3 7 5 Version 12 16 2010 User Manual BASEMENT TUTORIALS SOIL DEF name soil fix 40 LAYER bottom elevation 0 4 fixed bed 0 4 m below the surface mixture mixture roughness elements j 3 7 1 5 Bed load boundary condition The bed load input is regulated with a boundary condition which determines the transport capacity at the cross section defined The factor for the bed load at the boundary is an important calibration parameter and depends on the transport formula Therefore this factor is different for single grain and multi grain simulations The outflow boundary is handled as in the single grain simulation BOUNDARY type transport capacity string name Inflow_sed mixture mixture inflow factor 1 0 BOUNDARY type IODown string name Outflow 3 7 1 6 Bed load parameter For the sediment transport computation different bed load transport formulas are available In this tutorial the formula of Meyer Peter and Mueller for multiple grain classes is chosen It is suggested to try different sediment transport formulas U IV 3 7 6 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS
49. mesh properly in SMS and to consider the generated DTM just as a terrain model from which to get the elevation information VAW ETH Z rich U III 4 3 7 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE BASECHAIN GEOMETRY CROSS SECTION 570418 0 403 New Tags Blocks CROSS SECTION C570359 0 462 CROSS SECTION 570269 0 552 Add Block 1 available CROSS SECTION C570212 0 609 CROSS SECTION C570141 0 68 CROSS SECTION C570061 0 76 CROSS SECTION 569926 0 895 CROSS SECTION C569846 0 975 CROSS SECTION 569646 1 175 CROSS SECTION C569466 1 355 CROSS SECTION C569255 1 566 CROSS SECTION C569150 1 671 CROSS SECTION C569049 1 772 CROSS SECTION C568865 1 956 CROSS SECTION C568744 2 077 CROSS SECTION C568636 2 185 Fig 14 GUI of the BASEMENT ID grid file editor The 1 D BASECHAIN GEOMETRY can be exported with Export DTM for BASEplane under the menu bar Tools U Ill 4 3 8 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 5 Built In GUI Tools In this section some built in BUI tools are explained and information about the usage is provided Built in GUI Tools will pop up if a certain tag is activated by the user 5 1 Interactive Visualization during run time using BASEviz BASEviz is a small and lightweight visualization tool which can be used to visual
50. of Contents 1 QGeneral 1 1 Purpose ofthis manual urissa i aa accede usa 1 1 1 2 The Graphical User Interface GUI 2 1 The BASEMENT Main Window J T J 2 1 1 22 General Topics of Editing Files eater ro J J T J J 2 2 1 2 2 1 BASEMEBINI EclilOl 2 29 52 23 58 95905205 2 2 1 222 SOIL and lags xdi dou velia viven dovete ed ive bom dU edu u E 2 2 1 2 2 2 1 Add BIOGKS skua a suka Sat kaun hn 2 2 1 2 2 2 2 SMMC L Y O MEE 2 2 2 2 2 2 3 Remove BIOCKS Ol T age eec YE i vex Eee vus ako ve roe RE CE UE Duns 2 2 2 2 2 3 Automatic uu uu anun eid dama acta Gui 2 2 2 2 2 3 1 Mandatory Blocks and Tags 2 2 2 2 2 3 2 I 2 2 2 2 2 4 Use the Built in Help Function 2 2 2 3 Edit Command File 3 1 BASEMENT Command File Q J Q J 3 1 1 3 2 Create New or Edit Existing Command File 3 2 1 39 Jo t 3 3 1 3 9 1 EdT RAW A Hr 3 3 1 4 Edit 1 D Grid 41 The BASEMENT 1 D Grid File Editor J J J J 4 1 1
51. of the vertical setup for a computational cell within the models The characteristic values are indicated relative to a joint surface e g riverbed level or to a layer e g granulometric composition of bed material in layer S1 Their properties are represented in the balance point of the corresponding joint plane This results in a simplified model of the layering for a computational cell The characteristic data used in the model to describe the state and conditions of the surface are defined as followed VAW ETH Z rich Il 2 3 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING Position lt 3 bottom elevation bed level Zai elevation level of the lower closing joint plane of the corresponding sublayer Sub ie funy with m maximum number of s Sublayers Zo elevation level of the lower joint face of sublayer Sn which finishes the model downwards respectively describes the position of the non erodable underground all variables are measured in m a s l or in m relative to a userdefined reference system Attributes m equivalent sand roughness based on Nikuradse Description of the surface roughness e g grass sealed o plane etc default value or derived by grain distribution covering of the first sublayer N m critical value for begin of sediment movement at the surface in the sense of a rised erosion constancy e g by natural cover default values mass fraction of the g grain c
52. simulation to a morphological simulation An outline of outputs is given and possible visualization is shown for each step http www aquaveo com sms http www tecplot com U IV 3 1 2 VAW ETH Zurich T Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 2 Computational grid The computational mesh is generated with the pre processor program SMS Its detailed setup with SMS is not part of this tutorial Here just important features and characteristics of the computational mesh for the modelling with BASEMENT are mentioned The mesh discretizes the topography of the river in such a way that the important topographical information is maintained Break lines in the mesh are ensuring that important features of the topography such as the river bed and dike crests are represented correctly Fig 13 An important feature is the assignment of the material index to the different groups of elements By the material index different properties such as the friction factor and the soil properties can be assigned The material index is mainly used to assign the friction factor to the different river sections separately For example it is usual to assign different values for the main channel embankments and further surrounding land Fig 15 Elevation m a s 1 Fig 14 Computational mesh generated by SMS for a section in the widening part The bold black lines are break lines for the mesh VAW ETH Z rich U IV 3 2 1 Version 12 16 2010
53. tal 9 show velocitie 0 show discharge time 53280 s Fig 15 Visualization of BASEchain with BASEviz VAW ETH Z rich U III 5 1 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE e BASEviz for 2 D simulations with BASEplane The unstructured 2 D mesh is plotted in combination with a contour plot of a chosen output flow variable Optionally velocity vectors can be added to the data visualization H BP 4 H BP 4 Jog water depth m 49 5 24 8 12 4 0 000 vtk help use left mouse button fo rotate viev use middle mouse button to shift viev use right mouse button wheel to zoom vlev h toggle thb help tex D reset vlev e or q to quit the simukitioi w turn on wireframe styk 6 turn on surface styk 9 toggle grid line p pause simulatio 1 toggle 3D water surfac 2 toggle velocity vector 6 show water deptr 6 show water elevatiol 7 show bedz change 8 show tai 9 show velocitie 0 show bedloac show verticalaccelerqtio time 76 1731 s Fig 16 Visualization of BASEplane with BASEviz BASEviz is based on the visualization libraries of the Visualization ToolKit VTK http www vtk org which makes use of OpenGL for rendering 5 1 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 5 2 Manual Controller Interface HID
54. the cadastral register on demand of the cantons Sedimentological geological data ourface characterization of the riverbed mostly using line samples of the erosion capable underground volume sampling or geological drilling and of the flow induced transported material grain size distribution from sieve analysis Possible data sources geology of cantons FOEN formerly BWG Nagra in situ suspended load and bed load measurements he estimation of sedimentologic data and its analysis is surely the most time consuming part At certain water bodies a continuous monitoring of suspended load exist However the granulometric size distribution is seldom measured Therefore the bed load near the surface but also the suspended load often have to be estimated under certain assumptions or they will have to be measured Hydrological data Temporal or stationary boundary conditions for the numerical model e g inflow discharges water levels and local sources or sinks Possible data sources Hydrological data from the federal measuring facilities specific rainfall discharge models e g IFU ETHZ retention models For larger water bodies within Switzerland observed by the FOEN time series and hydrographs are available online Smaller watercourses are often not covered and need either a hydrologic model or new measuring monitoring to determine the discharge VAW ETH Z rich U Il 2 2 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING
55. the four nodes lie within a plane But in case of strongly varying terrain topographies a bad placement of quadrilateral elements can lead to situations where this is not the case Such elements are deformed and have an ambiguous gradient Fig 3 illustrates a quadrilateral element with ambiguous gradient which is situated across a river dyke Fig 3 Left ambiguous quadrilateral element with false break line right correct discretisation of the dyke crest In such situations a splitting of the quadrilateral element into two triangles becomes necessary The selection of the correct break line within the quadrilateral element here along the dyke crest must usually be done manually according to local topography To facilitate this task most grid generating tools e g SMS offer special features for detecting quadrilateral elements with ambiguous gradients in the mesh U Il 3 3 2 VAW ETH Zurich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 4 Issues on triangulation Mesh triangulation and grid refinement play an important role in almost every numerical simulation Therefore a lot of different techniques have been developed to achieve suitable computational meshes The user is basically free to use any tool or method which generates a mesh of accurate quality out of the raw data This section shall give a short overview on some popular triangulation methods BASEMENT does not provide an automated routine for mesh generatio
56. to elements which are fully wetted or can be considered for all elements Over the material index the scope and the applied angles for the gravitational transport can be defined Note that for soils with a fixed bed the gravitational transport is not active The applied sediment transport formulas are basically just valid for the equilibrium sediment transport With the gravitational transport unevenness occurring due to sediment transport will be smoothed out U IV 3 5 6 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS GRAVITATIONAL TRANSPORT x index 1 234 5 6769 10 ad 12 3 angle failure original_dry 30 30 30 30 30 30 30 30 30 30 30 3072 angle failure original wetted i 25 X5 15 J5 15 db AS 25 35 15 15 15 angle failure deposited 10 10 10 10 10 10 10 10 10 10 10 10 gravity transport on cells partially wetted angle wetted criterion partially wetted VAW Z rich U IV 3 5 7 Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 5 2 Define the output The desired output of the simulation has to be defined explicitly in the OUTPUT block The output time step defines the time steps of the results The console time step defines the time step to appear in the BASEMENT window during simulation Specific output modes have to be defined in the repeatable SPECIAL OUTPUT blocks Inside this block the output time step defines the output time step for this particular output A d
57. within the river monitoring project Flaz of the Laboratory of Hydraulics Hydrology and Glaciology VAW In order to reduce the model size and thus computational run time only the three most interesting sub sections are modelled in this tutorial such as the lower part of the section enriched with roughness elements the widening part and the part with alternating bars shown in Fig 13 StMoritz N amo 1 5 n s S T N _ nx AR km 2 789 km2095 km1147 km0 217 km 4 126 former Flaz E steep section E roughness elements river widening alternating bars C channel E confluence Fig 13 Different morphological river subsections of the new section of the river Flaz VAW ETH Zurich U IV 3 1 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 1 2 Tutorial structure In a first step the important properties of the mesh file are shown The tutorial is designed to run BASEplane with the help of the software SMS as pre and post processor Furthermore the results can be post processed visualized with the software Tecplot Though the main focus is on the setup the command file for the numerical simulation with BASEMENT The tutorial is structured gradually in the way that first of all a calibrated hydraulic model is set up Based on this simulation the morphological part can be added to the simulation with a single grain model This procedure reflects the proposed way from a calibrated hydraulic
58. zbed z and eline for the last time step and use them to plot a longitudinal profile e g with Excel VAW ETH Z rich U IV 2 4 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS 373 talweg 3 2 water surface elevation 371 energy level 370 369 elevation m 368 367 366 0 500 1000 1500 2000 2500 3000 distance m Fig 6 Longitudinal profile As it seems that there is no problem we can proceed to the next step U IV 2 4 2 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 4 2 Perform simulation of the floods Thur2 Copy the following files in a new Folder or take the ones in the second zip file Thur1 bmc ThurTopo txt InztialThur txt Extract the ThurHydrograph txt from the second tutorial zip file It contains the hydrograph of the flood event in 2005 T Q 0 30 648 3600 34 05 7200 37 305 10800 39 707 14400 41 18 18000 41 916 21600 42 275 25200 42 654 28800 43 646 32400 45 444 500000 1000000 1500000 time S Fig 7 Hydrograph of the flood event of 2005 VAW ETH Z rich U IV 2 4 3 Version 12 16 2010 User Manual BASEMENT TUTORIALS Rename the command file Thur2 bmc For the upstream boundary condition change the data file into ThurHydrograph txt BOUNDARY boundary type hydrograph boundary area upstream boundary file ThurHydrograph txt precision 0 001 number of iteratio
59. 08 VAW ETH Z rich Version 6 3 2010 System Manuals of BASEMENT PREFACE Preface to Version 2 0 Four years ago In spring 2006 the first version of the software system BASEMENT was completed and ready for internal use In autumn of the same year the first official version 1 1 of the software was released and made available as tree download on the project website www basement ethz ch Since then the functionality of the program has been enhanced and the international user community has grown gradually Over the last years BASEMENT has become a reliable tool for professional investigations especially within the scope of flood prevention and for scientific studies Furthermore the software is part and parcel of the lecture Numerical Models in Hydraulic Engineering to ensure education of young engineers in the field of hydrodynamic numerical simulation The lecture is held on a regular basis by VAW staff for master students of civil and environmental engineering at ETH Zurich In February 2009 have become the successor of Prof em Dr Ing H E Minor as Director of the Laboratory of Hydraulics Hydrology and Glaciology VAW at ETH Zurich In the meantime have joined the project committee Integrales Flussgebietsmanagement as further representative of VAW besides Dr R Faeh Furthermore there are some changes concerning the personnel of the project team of BASEMENT to mention Lukas Vonwiller joined the team last autumn after ha
60. 16 2010 User Manual BASEMENT TUTORIALS Two types soils are defined one which is fixed code 1 and one with a sub layer of 5 m thickness which is attributed to the bed bottom where bed load takes place code 2 Add twice a block of type SOIL_DEF The first one needs only a name as it has no layers of material In the second one add a LAYER block Then give the layer a bottom elevation and a mixture SOIL DEF name fixed SOIL DEF name mobile LAYER bottom elevation 5 mixture unique 2 5 2 Soil assignment The names of the described soils have now to be assigned to the soil codes used in the topography file Add a SOIL_ASSIGNMENT block and there the attributes type index and soil The first value in the index window has to correspond to the first name in the soil window etc CA D Thur3 1D Thur3 bmc BASEMENT command file editor ole File Tools Input Structure E BASEMENT PROJECT DOMAIN PHYSICAL PROPERTIES BASECHAIN 1D Thur Altikon GEOMETRY HYDRAULICS BOUNDARY hydragraph BOUNDARY harelation INITIAL FRICTION PARAMETER SECTION COMPUTATION MORPHOLOGY PARAMETER SO ASSIGNMENT A FZ Es New Tags Blocks all set nothing left v index Fable vw index Javea soil BEDMATERTAL GRAIN CLASS MIXTURE unique SOIL DEF Fixed SOIL DEF mobile BOUNDARY BOLINDARY PARAMETER 3 OUTPUT SPECIAL OLITPLIT Eecplot all SPECIAL
61. 2 range 167 807 243 755 CROSS SECTION name P7020_95 distance_coord 70 20 reference height 0 00 main channel range 146 363 260 233 friction coefficients 31 35 31 friction ranges 0 000 146 363 146 363 260 233 260 233 336 420 active range node_coords 0 000 418 005 6 401 420 752 10 110 420 869 17 751 321 601 14 658 423 483 16 855 423 629 17 751 423 572 22 284 421 229 92 451 420 263 141 797 420 260 142 699 420 708 146 363 420 721 150 504 418 320 151 095 418 354 159 533 418 876 162 508 416 526 164 873 414 460 v 1 amp 6 SEO did dan Line 2010 Col 27 No errors or warnings Press Validate to check again Validate Apply Fig 7 Grid File Editor Raw Edit Window 4 3 2 Friction With this tool the friction value of the main channel the forelands and the bottom can be assigned to a range of consecutive cross sections The names of the first and the last cross section of the range have to be given VAW ETH Z rich U Ill 4 3 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE C3 BASEMENT v2 From CS P50000_95 P6940_95 Main Channel Resistance 33 Bottom Resistance Foreland Resistance Fig 8 Friction assignment 4 3 3 Remove Nodes Cross sections often consist of a large number of nodes and slices which consumes significant computational
62. 296 U IV 2 2 1 User Manual BASEMENT TUTORIALS Additionally the distance from the upstream end of the channel first cross section has to be determined for each cross section The obtained geometry points can be introduced in the topography by copy pasting it directly into the node coordinates field in the grid file editor The editor will translate the column wise data into the proper syntax Another more efficient way is to use the python scripts available on www basement ethz ch to transform topography data in excel format into the BASEMENT format in a first step Example CA D Thur1 1 D Thur bmeg BASEMENT 1 0 grid file editor File Tools Input Structure BASECHAIM GEOMETRY CROSS SECTIOM node coards 0 376 264 1 455081097 376 3273 4 349044033 377 804 5 134094857 378 133 5 803278107 378 238 8 241452785 378 227 0 123103693 377 965 10 23346129 377 395 4 I8 AA Block Error Tag name is mandatory but missing Block Error Tag distance is mandatory but missing Fig 2 Cross section points inserted in the topography editor The minimum information we have to provide for each cross section besides the node coordinates are the cross section name and the distance coordinate measured from upstream to downstream in km U IV 2 2 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 2 2 Definition of different cross section zones To reduc
63. 5 66 65 CROSS SECTION P6680 95 66 80 CROSS SECTION P6700 95 67 00 CROSS SECTION P6720_95 67 20 CROSS SECTION P6740_95 67 40 CROSS SECTION P6760_95 67 60 CROSS SECTION P6780_95 67 80 Cross Section View Voce nO nee em QUAL ATS 4 SOIL DEF CROSS SECTION P6840 95 68 40 CROSS SECTION P6860 95 68 60 CROSS SECTION P6880 95 68 80 CROSS SECTION P6900_95 69 00 B CROSS SECTION P6920 95 69 20 CROSS SECTION P6940 95 69 40 CROSS_SECTION P6960 95 69 60 CROSS SECTION P6980 95 69 80 E CROSS SECTION P7000 95 70 00 CROSS SECTION P7020 95 70 20 CROSS_SECTION 7040_95 70 40 CROSS SECTION P7060 95 70 60 j CROSS SECTION P7080 95 70 80 active CROSS SECTION P7100 95 71 00 i CROSS SECTION PF120_95 71 20 CROSS_SECTION P7140_95 71 40 CROSS SECTION 7160 95 71 60 S CROSS SECTION 7180_95 71 80 CROSS SECTION 7200_95 72 00 P6820 95 CROSS_SECTION 7220_95 72 20 CROSS SECTION PZ240_95 72 40 CROSS SECTION P7260 95 72 60 OPENS m CROSS SECTION P7280 95 72 80 CROSS SECTION P7300 95 73 00 CROSS SECTION P7320 95 73 20 CROSS SECTION P7340 95 73 40 CROSS SECTION P7360
64. 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 2 Coupling Types The implemented coupling types are briefly sketched in the table below Single sub domains can be combined sequentially via coupling interfaces at the upstream or downstream boundaries This can also be done for sub domains with mixed dimensionalities 1 D 2 D 2 D 1 D These sequential coupling types can be used to combine sub domains over their boundary conditions or external sources For example a weir outflow boundary can be combined with an input hydrograph of a downstream boundary Coupling interfaces for river junctions or river bifurcations allow a simplified modelling of conjunctions of river branches within a 1 D river network For integrated 1 D and 2 D modelling a 1 D sub domain can be coupled laterally with a 2 D sub domain The coupling takes place along the river channel via multiple coupling interfaces which connect cross sections 1 D lateral coupling with corresponding mesh elements 2 D Tab 2 Listing of different coupling types and their descriptions VAW ETH Z rich Ul 6 2 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 6 2 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 3 Coupling Mechanisms Explicit coupling of sub domains Coupling of sub domains is implemented as an explicit coupling approach
65. ACE CA Cross Section Interpolation Range From Cross Section 563136 to S62 34 4 Longitudinal Spacing Max distance between cross sections m 20 Transversal Spacing Use max distance between points in interpolated cross section e Use local segment spacing Interpolation Alignment Fixpoint Spline Alignment 9 Interpolate Angle Spline Contrals Strength of spline orthogonality at Fixpoints 1 0 Master spline is based on Fixpoint 1 wi Interpolate Fig 13 Setup dialog for the cross section interpolation In Fig 13 the setup dialog for the interpolation is shown The different parameters are explained briefly in the following By clicking on nterpolate the interpolation of the cross sections finally starts if all data is available First of all the Range of the interpolation must be defined This is done by specifying two subsequent cross sections which are chosen from a list of all existing cross sections in the drop down menus Another important parameter is the Longitudinal spacing which determines the resolution of the interpolated grid Enter the maximum distance between two interpolated cross sections in m If you choose a small value than many cross sections in small distances will be generated if you choose a large value only few cross sections in large distances will be generated The optimal choice depends on the type of simulation Furthermore also the Transversal spacing c
66. Attribute Obligatory size number of data values time time of data values in sec Yes Q h v Type of data encoding ascii binary No default ascii little endian boundary name of boundary condition Only if data is sent to of data values BASEMENT timestep current time step of model in Only for local time Sec stepping Data communication The data communication via sockets can be compared to data exchange via file streams The data packets are inserted into a pipe and the other side of the connection reads the contents after the FIFO concept First In First Out The receiving part of the connection must parse the contents of the pipe and extract the data packets The time attribute of the data packets indicate the time level of the other program required for the synchronization If the time levels of the data packets are behind the program s time or if no data is in the pipe than the program must wait and continuously check for incoming data In case of local time stepping the data packets also carry the information of the local time step size which has to be used read from stream Fig 20 Sending and receiving data from socket stream FIFO pipe VAW ETH Z rich Ul 6 6 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 6 6 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 7 Flow Control in River S
67. EMENT TUTORIALS IV TUTORIALS Part 1 Applications of BASEchain 2 Hydrodynamics and sediment transport at the river Thur 2 1 Introduction 2 1 1 General description This Tutorial describes the necessary steps for the simulation of hydrodynamics and bed load in a specific section of the river Thur In the considered section a river widening has been realized during the last years It s located in Altikon and illustrated in the photo below The flow direction is from right to left The bed modification over a year including an important flood will be simulated Fig 1 View of the simulated river section 2 1 2 Used features In this tutorial will be treated the following points e Preparation of the needed input files e Simulation of a steady flow to use for the following simulations e Use of composite cross sections e Simulation of bed load with formula of Meyer Peter Muller e Use of dry initial condition VAW ETH Zurich U IV 2 1 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS e Use of a file to define the initial conditions e Use of the following boundary conditions o Inflow hydrograph o Inflow of sediment in out o Outflow h q relation o Outflow of sediment in out e Representation of the results 2 1 3 Purpose In the year 2005 intensive rainfall led to a large flood event The aim of the simulations in this tutorial is to study which influence this flood had on the geometry of the channel of the r
68. GIS Geography Markup Language GML additional information as topology and other attributes e g time are required A further possibility to structure geographical data in a GIS is a splitting on different topic layers Digital terrain models with height information are represented in a GIS either as TIN triangulated irregular network or as a GRID structured mesh With regard to numerical simulation models the topology of a TIN or a GRID corresponds to unstructured resp uniform computational grids 2 5 2 Plane assignment for point data In a GIS real area related conditions are given in an idealized way On the one hand there is a limited number of attributes and on the other hand the values over the surface are averaged Partially the data base is just point wise available and just sparsely against resolution and process scales of numerical simulation models e g at geological probe holes Therefore the coarse values have to be extrapolated on the corresponding surfaces of the numerical grid The determination of the corresponding surface or i e the surrounding polygon needs different geometric constructs as e g Dirichlet Tesselation Voronoi Polygons Additionally one should consider related information from superior scales e g geological maps with layering data and downcasts 2 5 3 Interoperability and standard interfaces assure interoperability meaning system independent communication between different inf
69. II 1 1 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE This page has been intentionally left blank 1 1 2 VAW Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 2 The Graphical User Interface GUI 2 1 The BASEMENT Main Window Starting BASEMENT will first produce a Graphical User Interface as shown in Fig 1 On the top of the screen a menu bar consisting of the menus File Options and Help is available Below the menu bar near the BASEMENT logo there are four action buttons named Edit Command Edit 1D Grid Run and Stop The main window displays a splash screen indicating the current version of the Software A yet empty progress bar is located below the main window Ci BASEMENT File Options Help BASEMENT Version 2 0 1 R894 SESSSSSS SES PSSSSS SSSSSESS BF PE SSSSSSSS SN SS SSSSSESE 8 88 SS SN SS SS SES SES S FEO SS 88 SN SE SESS FEE SESS SSSSSSSS 88 8 88888 88888 8 SES EE FE SS S SS SSSSSSSSES SS SS SSSS SS SS SN SE SS PE SS FHF SESSSSSS SS 88888 FRRRRRR SS SSSSSSSS SE Basic Simulation Environment For Computation Environmental Flow nd Natural Hazard Simulations version 2 0 1 K854 mailto basementlH ethz ch august 2010 http basement ethz ch Copyright cj 2006 2010 ETH Zurich
70. In order to create a controller a new CONTROLLER block is generated in the DOMAIN block The HID controller provides an interface for the manual operation Fig 17 The control window will pop up automatically after starting the simulation with the start button In the CONTROLLER block several manipulated variables and controlled variables can be defined The manipulated variables will appear on the left hand side of the controller interface whereas the monitored variables will show up on the right hand side Fig 17 In this example two manipulated variables height of a weir and height of a gate and two monitored variables discharge over the weir and trough the gate are selected With the cursor the slide can be moved within the predefined range of the manipulated variable Additionally the target value can be entered directly into the white text box Target As the simulation proceeds the impact on the monitored variable is visualized on the chart on the right hand side Additionally the output and the impact of your control measures can be visualised with BASEviz chapter 5 1 BASEMENT v2 _ JG 3 Weir height Weir _ Value Root value 100 65 Target 100 65 Reset scale 2 450 2 500 2 550 2 600 Time 5s Turbine gate height Turbine _ g Value Root value 100 04 Target 100 04 ee ee Reset Yscale 2450 2 500 zogi 2600 Time Fig 17 Interface for the manual control and monitoring of the sel
71. NG For the 1d model it might be necessary to interpolate cross sections or deduce cross sections from a DEM digital elevation model 1 1 2 2 Hydrologic data At all boundaries of the mesh hydrologic boundary conditions such as hydrographs or time series of water levels have to be provided In the case of a simulation with sediment transport also a sediment concentration in the water might be needed The choice of boundary data has to be made with care considering the type of event being simulated The data might be created especially for the wanted simulation hypothesis or be adapted from existing measured or statistical data Some times special manipulation of the data turns out to be necessary for instance to omit discharges not relevant for sediment transport Finally again the hydrologic data has to be put in the format wanted by the program 1 1 2 3 Sediment data Sediment data primarily comes from water sediment samples or surface samples like the line method Possibly a grading curve still has to be built from this raw data Then the number of desired grain classes for the simulation has to be chosen and the characteristic grain classes need to be identified Based on the grain distribution other values like roughness or angle of rest may have to be calculated 1 1 3 Boundary conditions The boundary conditions define quantities at the margin of the computational region during the whole simulation time These are typically hy
72. OLITPLIT monitor 9 Fig 10 Soil assignment in the user interface U IV 2 5 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 5 3 Define general parameters for sediment transport The porosity and the density of the material are standard values The active layer is kept fixed and set to 20 cm The tables for the hydraulic computation will be updated each time when the bed level has changed more than 5 cm PARAMETER porosity 0 37 control volume thickness 0 2 density 2650 max dz table 0 05 VAW ETH Z rich U IV 2 5 3 Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 5 4 Define specific parameters for bed load transport The Meyer Peter and M ller bed load approach will be applied without adjusting the calculated transport capacity bedload_factor 1 0 The parameter for upwind scheme is set to 1 and for the critical angle a standard value has been choosen PARAMETER bedload transport mpm bedload factor 1 upwind 1 angle of repose 30 2 5 5 Define boundary conditions for bed load At the downstream boundary it is considered that the quantity of sediment which enters the last element leaves it by the boundary BOUNDARY type IODown string downstream At the upper boundary the observed modification of the bed level before and after the floods is very small For this reason it can be assumed that at the upstream boundary there is as much sed
73. SS SECTION P56200 95 56 200 CROSS SECTION P56400 95 56 400 THE CROSS SECTION P56600 95 56 600 CROSS SECTION P56800 95 56 800 EH E CROSS SECTION P57000 95 57 000 CROSS SECTION P57200 95 57 200 CROSS SECTION P57400 95 57 400 CROSS SECTION P57600 95 57 600 CROSS SECTION P57800 95 57 800 CROSS SECTION P58000 95 58 000 EE E EE EHE HERE ERE EE EIER EL EE ERE HERE ERE E CROSS SECTION P58200_95 58 200 CROSS SECTION P58374_95 58 374 ZODA Dam cr CELL roe oo or ra EE GREE EEE EL ER GEL EE EIER REI ERI HER GEH ER REL HL Fig 11 in red the guessed fix points for cross section interpolation It is recommended to check the points visually and add other important points especially on the break lines For the interpolation all involved cross sections must have the same number of fix points 4 3 5 Interpolation First of all before an interpolation of 1 D cross sections can be performed some information is needed about the spatial alignment of all cross sections in the x y plane There are two main tags which determine the spatial orientation of the cross section which are crucial for the interpolation algorithm The orientation_angle provides the information which is needed for the orientation of the cross sections This is the angle between the normal vector of the cross section and the vector in x direction 1 0 Consequently in a fu
74. Stop is only active if a simulation is currently being carried out Pressing this button will stop the current simulation U Ill 2 1 2 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 2 2 General Topics of Editing Files 2 2 1 BASEMENT Editor Both the Command File Editor and the 1 D Grid File Editor share a common composition The Window is subdivided into three parts the Input Structure to the left the Main View to the right and the Validation Messages at the lower right corner Fig 2 The Input Structure shows the tree of all Blocks defined and allows the selection of a specific Block The Main View shows all relevant Information for the currently selected Block like available Sub Blocks Tags and the values for all chosen Tags Graphical visualization of e g a Cross section or a time series can also be seen The Validation Messages indicate by their Color whether the Input for the selected Block contains any Errors or Warnings D Vlaz hydraulic stationary Flaz hydraulic stationary bmc BASEMENT command file editor Jae File Tools Input Structure Pa Main View BASIMENT PRUE New TagsfBoc s DOMAIN 1 11 avallable PHY ICM ppi PERLTIES adag FE lt BASEPLANE zD Flaz ame tyne Information STRIMGDEF Inflow STRINGDEF Outflow hydrograph 2 HYDRAULICS BCURDARY hydragraph file PRY here ation Inflow _stationary txt Al N load hle edit Delete PEC AL
75. System Manuals of BASEMENT PREFACE Preface to Versions 1 4 The work since the first release of the software in October 2006 was exciting and challenging go public is paired with interests and demands of users although user support for the software never was intended But interchange with users is definitely one of the most crucial factors of successful software development Feedback from academic or professional users conveys a different point of view and enables the development team to achieve costumer proximity as well as to consolidate experience Accordingly the project team tried to meet the demands as effectively as possible In version 1 3 of BASEMENT which was released in April 2007 there were some errors fixed a few new features added and the documentation was completed Since then many things have changed on the personnel on the project as well as on the software technical level In summer 2007 one of our main software developers Dr Davood Farshi left VAW and changed to an international hydraulic consultant Dr Farshi supported our team from 2002 to 2007 as a profound numeric specialist and was mainly involved in the development of BASEplane At his own request he is still engaged in the development of BASEMENT as external advisor and tester Dr Farshi s position in the project team was reoccupied by Christian Volz an environmental engineer from southern Germany Mr Volz has broad experience in numerical modelling a
76. TUTORIALS 3 4 Perform hydraulic simulation 3 4 1 Perform steady flow simulation Open the command file Flaz_hydraulic_stationary bmc either by double clicking or via the menu of the BASEMENT GUI File gt Open Command Run the simulation with the Run button of the BASEMENT window If the SPECIAL_OUTPUT of the type BASEviz is chosen press the keyboard button p to start the simulation Be aware that the mesh command file and all other input files have to be in the same folder The output files are stored in this same folder In order to check the mass conservation of the model the file Flaz combined th dat is used After approximately 1600 seconds the outflow counterbalances the steady inflow Fig 19 In the file Flaz_balance dat the run time of the simulation the computational time steps and the element which is limiting the computational time step are stored The identification of the limiting element allows for improvement of the mesh at the indicated location by the use of the mesh generator The solution files with the ending so can be imported into the program SMS and the water depth and flow velocities can be visualized as shown in Fig 20 At the end of the simulation the flow variables of the last time step t 3000 s are stored in the Flaz_old_Flaz sim file This file can be used later on to continue the simulation 0 500 1 000 1500 2000 2500 3000 time s Fig 19 Steady inflow hydrograph and outflow hydrograph VAW ETH
77. TUTORIALS This page has been intentionally left blank U IV 3 8 10 VAW ETH Z rich Version 12 16 2010 APPENDIX AND INDEX F Ea Les b B gem y r 0 Lab w Ge 0 U J System Manuals BASEMENT This page has been intentionally left blank VAW ETH Zurich System Manuals BASEMENT APPENDIX AND INDEX Table of Contents A Notation Version 4 23 2007 A 1 Super and Subscripts A 1 1 A 2 Differential Operators L l timo date Eo n la A 2 1 A 3 English Symbols nu u u MA ta duelo at cou desea uA A 3 1 A 4 Greek Symbols u E UEM ECT TRU DI A 4 1 VAW ETH Z rich i System Manuals BASEMENT APPENDIX AND INDEX This page has been intentionally left blank ii VAW ETH Zurich Version 4 23 2007 System Manuals BASEMENT APPENDIX AND INDEX A Notation A 1 Super and Subscripts 5 2 Oj Js sup Oe Wer Qoo Os VAW ETH Z rich Version 4 23 2007 Property of top most soil layer for bed load active layer Critical value Index corresponding to three dimensional Cartesian coordinate system IR with coordinates X y z Property corresponding to g grain size class Property on the left hand side Lateral property n step of time integration Property on the right hand side Property at water surface Property of bed
78. The incremental insertion algorithms successively Insert new points to an existing Delaunay triangulation These algorithms have a worst case running time of if the points are badly ordered But in practice it is near to O nlogn for Green Sibson VVatson or incremental delete and build fas e Fig Z a point insertion and determination of affected triangles b new triangulation In this algorithm after the insertion of the point all the triangles containing the edge q are searched Then the edges of these triangles visible to q are deleted and the new edge is connected with the vertices of the originated polygon creating new edges Green Sibson VA g Fig 8 a insertion of the new point b edge swapping based on empty circle criterion After its insertion the point q is connected to the vertices of the triangle that contains q VAW ETH Z rich Version 10 22 2009 U Il 3 4 4 User Manual BASEMENT PRE PROCESSING Then all suspect edoes have to be swapped to satisfy the empty circle criterion if we want to obtain a Delaunay triangulation Other edge swapping criteria can be used for instance the minimization of the maximum angle 3 4 2 4 Edge flipping algorithm The edge flipping algorithm is based on the local optimization of an initial triangulation For each quadrilateral formed by a convex pair of triangles the diagonal is chosen with regard to a local optimization criterion Possible optimization crit
79. To grasp the meaning of the different parameters it is helpful to understand the basics of this interpolation algorithm This interpolation algorithm bases on the creation of spline curves a spline is a special polynomial function which is often used for smooth interpolations between given points For each fixpoint of the cross sections such a spline curve is determined which connects all the corresponding fixpoints with each other in a smooth way Therefore every cross section must have the same number of fix points Furthermore the spline curves have the special property that they are aligned orthogonal to each cross section profile After the spline curves have been calculated the positions of the new interpolated cross sections are determined in given intervals along the spline curves As soon as these positions are known the cross sections are created orthogonal to the tangent direction of the master spline To determine the fixpoints of the new cross sections the intersections of this orthogonal cross section line with all spline curves of the other fixpoints are calculated Finally the new cross section points are determined in between the fixpoints in a given transversal distance interval The elevations of the cross section points are finally determined using a weighting procedure between the elevations of the left and the right cross section VAW ETH Z rich U Ill 4 3 5 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERF
80. UI enhances the usability but it is still possible to work with BASEMENT console It is now possible to define the whole Command File using the GUI This avoids Syntax Errors within the Command File compared to the versions where the Command File was created manually Furthermore the Command File Editor validates the current state of the Input File and indicates whether there remain some Errors or Warnings Grid generation for 1 D simulations has never been easier The 1 D Grid File Editor allows the definition of cross sections and provides a graphical visualisation of the whole river reach and also every single cross section There are many additional tools to work on cross sections which facilitate the setup of a 1 D geometry The intention of this document is to help the user working with the Graphic User Interface The common basic behaviour is explained in Chapter 2 The Use of the Command File Editor is described in Chapter 3 and the Explanation of the 1 D Grid File Editor can be found in Chapter 4 In Chapter 5 interactive Visualisation and Manipulation tools during the runtime of a simulation are shown In some situations it may be desired to run the program without GUI and without user interaction e g to execute several program runs via batch script over night or when running the program on a high performance machine Further details concerning the batch execution mode are explained in the user manual UI VAW ETH Z rich U I
81. ULICS Dod 2 3 4 2 1 Define the upper boundary condition The upper boundary condition is defined by a hydrograph which is stored in a separate file Indicate also the precision with which the discharge corresponding to the iteratively determined area must correspond to the given discharge and the maximum number of iterations allowed to reach this precision The slope of the first cross section must be given in per mille the last 3 values are used only in case of supercritical flow BOUNDARY type hydrograph string upstream file ThurSteadyHydrograph txt precision 0 001 number of iterations 100 slope 0 93 U IV 2 3 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 3 4 3 Define the lower boundary condition The lower boundary is an h q relation which is calculated internally Again we have to define the boundary condition with a specific slope BOUNDARY type hqrelation string downstream slope 1 5 2 3 4 3 1 Define initial condition The channel is considered to be initially dry Note that starting with a dry channel is for the depth average equations a numerically delicate problem So this option will require some care when we set the numerical parameters INITIAL type dry 2 3 4 3 2 Define default friction values The declaration of a default friction type and a default friction value are mandatory The friction values are overwritten by the values decla
82. Ul 7 2 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U I 7 2 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 7 3 Controller Types 7 31 PID Controller One possible approach to describe the mathematical function f is a PID partial integral differential controller This type of controller relates a monitored variable to a manipulated variable by three additive controller elements J d u t K m t tdt Ky ym s lt Av 7 9 gt r hs gt P Element I Element D Element Internally the PID controller is implemented in its differential form i e the change of is calculated in each time step The three required variables are K and The correct definition of these variables is very crucial to the proper operation of the controller Which values should be used is highly dependent on the system and therefore requires some care and experience The P element represents an adjustment proportional to the deviation and therefore only limits the deviation but does not bring the system back into the state where no deviation exists For this reason the Il Element integrates the deviation and consequently the system can be forced into its equilibrium state If the response of the I Element is too strong compared to the P Element the system oscillates If the values of both P and
83. User Manual BASEMENT TUTORIALS Material Indexes Roughness_elements_bed Id 1 1 Roughness_elements_embankment Id 2 Roughness_elements_surroundings Id 3 Widening_bed Id 4 Widening embankment Id 5 Widening surroundings Id 6 Alternating bars bed ld 7 5 Alternating_bars_embankment Id 8 Alternating bars surroundings Id 9 fixed_bed Id 10 boundary fixed bed 20 cm ld 11 boundary fixed bed 40 cm ld 12 Fig 15 Material indexes Ids used for assignment the friction factor The mesh file is saved as Flaz mesh 2dm and has the following structure MESH2D E3T eN 1 2 n3 eMi triangle element E4Q eN 1 2 n3 n4 eMi qudrilateral element ND ni x y Where E3T and E4Q are the flags for the triangular and quadrilateral elements respectively eN denotes the element number n1 n2 n3 and n4 denote the node numbers of the element and eMi is the material index of the element The elements are defined in a counter clockwise direction The coordinates of the nodes are defined in the second block ND is the flag for a node ni denotes node number and x y and z are the coordinates of the node U IV 3 2 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 3 Setting up the command file The command file with the ending bmc can be built up and changed within the graphical user interface GUI or in any text editor It has the fo
84. al slope is used in order to calculate the normal flow depths and the normal flow velocities at the boundary and can be considered as a calibration parameter A sensitivity analysis of this parameter makes always sense In any case the upper and lower model boundary should be far away enough from the river section of interest in order to minimise the influence of the boundary conditions BOUNDARY type hqrelation string name Outflow Slope 2 0 per mill 3 3 5 1 3 Initial condition The INITIAL block defines the flow variables at the beginning of the simulation In a very first step the simulation is started with a dry initial condition INITIAL type dry 3 3 5 1 4 Friction The FRICTION block defines everything that is related to the friction term in the shallow water equations Within the computational mesh a material index is assigned to all elements By the use of this material index See Fig 15 a friction factor can be assigned The default friction is used whenever there is no friction assigned to an element U IV 3 3 6 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS FRICTION type strickler default frictiom 30 input type index table index 1 2 3 4 5 6 7 8 9 10 11 12 friction 28 30 35 30 30 30 32 32 35 28 28 29 J wall friction off 3 3 5 1 5 Computational parameters The PARAMETER block defines the control parameters for the numerical simulation of the hydrauli
85. an be specified It determines the spacing of the points in the newly generated cross section profile There are two possible choices here two determine the transversal spacing You can either explicitly specify the maximum distance in m using the first option Alternatively by using the second option the distance is chosen automatically from the left and right cross sections by the interpolation algorithm local segment spacing The alignment of the new cross sections in the x y plane can be determined with two different methods in the nterpolation Alignment section The Fixpoint Spline Alignment means that the cross sections are always oriented orthogonal to the master spine s tangent U Ill 4 3 6 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE direction On the other hand using the option nterpolate Angle the orientation of the new cross section is determined by interpolation of the orientation angles of the left and the right cross sections This latter option is recommended in strongly curved streams in order to prevent overlapping cross sections Finally in the Spline controls section some parameters of the spline calculations can be adapted to special needs The Strength of spline orthogonality parameter determines if the spline always must be completely orthogonal to the cross sections or not In strongly curved streams some relaxation from strict orthogonality different from 1 0 may lead to ni
86. as 4 1 1 O Grid Editore SECON VIOW 4 2 1 PiedduorcARauw Edit 4 3 1 4 3 2 9 Node removal dialog for setting up the tolerance eee 4 3 2 10s Schematic Sketch of node TEMOVEL ui eive SS s ico ob Ure doe A SURE 4 3 3 11 in red the guessed fix points for cross section interpolation 4 3 4 13 Curved alignment of the cross 4 3 5 14 Setup dialog for the cross section 4 3 6 15 GUI of the BASEMENT ID file editor The 1 D BASECHAIN_GEOMETRY can be exported with Export DTM for BASEplane under the menu bar Tools 4 3 8 16 Visualization of BASEchain with BASEviz 5 1 1 17 Visualization of BASEplane with BASEYVIZ aaassssssrsssssssssasa 5 1 2 18 Interface for the manual control and monitoring of the selected variables 5 2 1 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE II GRAPHICAL USER INTERFACE 1 General 1 1 Purpose of this manual Since Version 2 0 BASEMENT is not pure console application anymore The Graphic User Interface G
87. aterials provided with the distribution Neither name of Ken Martin Will Schroeder or Bill Lorensen nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY EXPRESS OR IMPLIED WARRANTIES INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT INDIRECT INCIDENTAL SPECIAL EXEMPLARY OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES LOSS OF USE DATA OR PROFITS OR BUSINESS INTERRUPTION HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY WHETHER IN CONTRACT STRICT LIABILITY OR TORT INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE CVM Class Library Copyright c 1992 2010 Sergei Nikolaev Boost Software License Version 1 0 August 17th 2003 Permission is hereby granted free of charge to any person or organization obtaining a copy of the software and accompanying documentation covered by this license the Software to use reproduce display distribute execute and transmit the Software and to prepare derivative works of the Software and to permit third parties to whom the Software is
88. ation before it can be used to make prediction of future evolution VAW ETH Z rich U IV 2 6 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS This page has been intentionally left blank U IV 2 6 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 7 Hydraulic computation using HEC RAS 3 1 3 In future releases BASEMENT will only support its own topography file directly For the support of HEC RAS topography files a separate converter program is planned VAW ETH Z rich U IV 2 7 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS This page has been intentionally left blank U IV 2 7 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS IV TUTORIALS Part 2 Applications of BASEplane 3 Hydrodynamics and sediment transport at the river Flaz 3 1 Introduction This tutorial gives an introduction to the capabilities of the 2 D modelling module BASEplane of BASEMENT It provides a step by step guidance on how build up a model for BASEplane 3 1 1 Case study description The tutorial for the 2 D modelling module is based on an extract of the case study of the river Flaz in Graubunden Within the framework of a high water protection project for the village Samedan a completely new section of the river Flaz was built On a length of 4 1 km morphologically different kind of river subsections can be distinguished Fig 13 The numerical modelling of the whole domain is carried out
89. ation is not given exactly at the desired node coordinates and therefore has to be interpolated The primary variables are defined somewhere inside the element e g the balance point The fluxes between two elements are defined at their corresponding edges Ul 3 2 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 4 Simulation Procedure The procedure to simulate a concrete problem setup is not unique BASEMENT is coded using an object oriented design which allows for flexibility and interchange ability concerning different application problems The possible combinations are manifold On the one hand the governing equations may change dependent on simplifications or extensions of certain terms use of sediment transport or pure hydraulics etc On the other hand there are miscellaneous numerical methods e g for time integration implicit semi implicit explicit or computation of spatial fluxes Therefore the main variables of interest differ from one problem to the other It is of great importance to plan carefully each simulation approach to a certain problem The most difficult and time consuming part is not the simulation itself but the acquisition of all needed data topography boundary and initial conditions and a proper setup of this data This section describes the main activities performed to execute a simulation with BASEMENT very general case In most problems only a part of them a
90. ations two types of meshes are used structured and unstructured grids Structured grids are simpler to use but need an interpolation of the data to determine the values at the desired vertex position if the input is an irregular point cloud In addition they are not sufficiently flexible to fit complex geometries Among unstructured meshes the triangulated irregular networks TIN are most convenient because they fit the irregular distribution and complex geometry of the topography best Furthermore they allow for a rapid transition trom small to large elements and the insertion and conservation of break lines BASEMENT is built on unstructured grids The computational mesh consists of vertices edges which connect the vertices and elements control volumes which are bounded by the edges VAW ETH Zurich U Il 3 1 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING The triangulation of terrain data is a special case of mesh generation as the vertices do not only have a position in the coordinate system but also elevation information This is a so called 2 5 dimensional problem U II 3 1 2 VAW ETH Zurich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 2 Topographical input data The original terrain data typically has a very Irregular distribution and a locally variable density Data can be available in different shapes A cloud of points x z e g digital elevation model Polygons e g digitalized conto
91. aulic model either for further hydraulic modelling or for morphological modelling in a further step U IV 3 4 6 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 5 Morphological simulation with single grain bed load transport The MORPHOLOGY block is not compulsory If this block is not defined the simulation is purely hydraulic The command file of the unsteady hydraulic simulation has to be completed for the single grain bed load transport as shown in this section The morphological simulation is based on the flood event in July 2004 Therefore a single grain bed load transport is added to the unsteady hydraulic simulation in chapter 3 4 2 In the HYDRAULIC block a small change has to be done in order to define the boundary string Inflow_sed for the bed load inflow Thus a new STRINGDEF block is added within the GEOMETRY block as follows GEOMETRY STRINGDEF name Inflow_sed node ids 3 4 5 6 7 3 5 1 Define the morphological information The necessary information for the morphological part of the simulation is defined in the MORPHOLOGY block MORPHOLOGY PARAMETER UNE BEDMATERIAL fel BEDLOAD UE GRAVITATIONAL TRANSPORT ND VAW ETH Z rich U IV 3 5 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 5 1 1 Morphological parameters In the PARAMETER block important parameters for the morphological simulation are defined The bed load control volume is chosen
92. ave only one single memory unit which is shared by multiple cores Fig 10 left side The parallelization of the software BASEMENT is implemented for such shared memory architectures This concept enables fast and easy communication between all cores through global access to memory Furthermore making benefit of parallel computing often is significantly easier and less time consuming especially for already existing sequential applications Such parallel computers with shared memory often termed multi core machines are highly available today at low costs The general trend in processor development is from multi core to many core systems with up to even more than hundred cores in cc NUMA systems As a consequence a major drawback of shared memory parallelization namely not being portable to distributed memory systems seems acceptable for an application like BASEMENT which is not focused on high performance computing Ul 5 1 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 5 2 Parallelization issues on shared memory systems 5 2 1 Levels of parallelization Parallelization in shared memory systems is based on multi threading concepts Threads are a way for a program to divide its work load into several independently running parts which are finally mapped on the available cores Threads can be started forked and terminated joined by an application in order to exploit parallelism provided by mu
93. be stored intermediately to guarantee conservation principles The data is finally passed over when the sub domains reach a common time level After the end of the loop of the level sequence all sub domains have been executed at least once and have finally have reached a common final time L nAt From this starting point the levels L are assigned again to the sub domains and the procedure is repeated U I 6 5 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT The selection of the base time level is done at the beginning of each level loop To account for the possibility that the minimum time step could change during the loop iterations due to changed flow conditions the base time level can be reduced by a factor F lt 1 for stability reasons VAW ETH Z rich Ul 6 5 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 6 5 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 6 External Coupling 6 61 Introduction The term external coupling means the coupling between the program BASEMENT and an external program This may be e g rainfall run off model which delivers input data for a river reach or it may be a standalone groundwater model which makes use of the stream water elevations computed by BASEMENT As described in the model coupling section one can also distinguish here
94. between one way coupling and two way coupling One way coupling Two different scenarios can be distinguished here e external Program may receive data which is sent by BASEMENT Therefore the external program must be defined as an external sub domain in the command file In the OUTPUT block an output must be defined and connected with this external sub domain Wile executing BASEMENT sends data as soon it is calculated using the output routines to the specified external sub domain The external program must fetch the data using TCP IP routines and must take care of the synchronization i e it must always wait until new data is available e Another scenario is to send input data to BASEMENT Thereby the external program again has to be defined as an external sub domain in the coupling process and it must be connected with other sub domains using boundary conditions Then the external program can send its data in the XML format to BASEMENT using TCP IP BASEMENT takes care of the synchronization within the coupling process and always waits until new data Is available Two way coupling It is also possible to couple an external program with BASEMENT with mutual data exchange Again the external program must be defined as an external sub domain in the coupling process Furthermore the external program must implement a synchronization mechanism in order to check if the needed data is available For the two way coupling the local time step
95. by joining a vertex to its nearest neighbour is an edge of the triangulation 3 4 1 1 Constrained Delaunay triangulation CDT The terrain data is sometimes provided in the shape of a PSLG as it contains break lines which must be conserved as edges in the triangulation In this case the constrained Delaunay triangulation can be used For the definition of a constrained Delaunay triangulation the notion of visibility of a point is needed In a PSLG domain a point D Is visible to a point if the open line segment CD lies within the domain and does not intersect any edges or vertices of P Point D is visible to CB if it is visible to some point on CB For the CDT the edge circle and the empty circle criterion are moditied as follows Edge circle for each edge a circle passing through its end points containing no other point of the domain visible to the edge exists Empty circle the circumcircle of every triangle contains no points visible to points inside of the triangle constrained edges Fig 5 a edge circle criterion b empty circle criterion 3 4 1 2 MinMax triangulation The MinMax triangulation minimizes the maximum angle It has proven to be very useful in CFD Bath 1995 U II 3 4 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 4 1 3 Data dependent triangulation A data dependent triangulation can be used for a 2 5 d problem Its aim is to find the best triangulation under data
96. c part The numerical simulation is performed using explicit time integration and the exact Riemann solver for flux computation The elements with a water depth below the minimum water depth will be considered as dry elements due to stability reasons The simulation is performed with a total runtime of 3000 seconds Later on it has to be tested that after this runtime the flow in the model domain has reached a steady state meaning that the outflow counterbalances the inflow see next chapter PARAMETER simulation scheme exp riemann solver exact CFL 0 95 total run time 3000 minimum water depth 0 05 minimum time step 0 0001 3 3 5 2 Define the output In the OUTPUT block the desired output has to be defined During the simulation output can also be visualized with BASEviz VAW ETH Z rich U IV 3 3 7 Version 12 16 2010 User Manual BASEMENT TUTORIALS OUTPUT output time step 1000 console time step 100 SPECIAL OUTPUT type BASEviz variable depth output time step 10 gridlines off vectors on SPECIAL OUTPUT format sms type node centered values depth velocity wse output time step 3000 SPECIAL OUTPUT type balance balance values timestep output time step 100 SPECIAL OUTPUT type boundary history boundary values Q history one file yes output time step 100 U IV 3 3 8 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT
97. c scheduling can improve performance in case of load imbalance but leads also to an increased overhead and suffers from bad data locality Consequently the decision between static or dynamic balancing is largely problem dependent synchronization Synchronization between threads can become time consuming if some threads must wait for other threads to finish execution Quite similar in some cases threads must be prevented from mutual accessing the same memory locations to prevent read write conflicts and data races Such parts of the code must be protected by setting mutual exclusions using locks These code parts can only be accessed by one thread a time and may cause other threads having to wait until access is granted Such bottlenecks caused by synchronisations and mutual exclusions should be avoided and minimized as far as possible They can sometimes be prevented by reorganising parts of the algorithms Prevention of memory conflicts can sometimes also be achieved by privatization of the problematic shared variables i e global variables are replaced by thread private variables VAW ETH Z rich U 5 2 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Locality When parallelizing a program attention should be paid on data locality aspects Modern cache based processors optimize execution speed by caching data which speeds up data load and store cycles Caches are very efficient if a processor can use the cached
98. cer shaped spline curves Some variations and iterative testing with this parameter may improve the interpolation result in such situations And finally also the fixpoint which determines the master spline can be chosen The master spline thereby is the spline which determines the orientation of the interpolated cross sections Please note In order to generate a 2D mesh from a given 1D mesh this interpolation option can be very helpful in combination with the Export DTM option 4 3 6 Export DTM for BASEplane This tool enables the user to convert a 1 D BASECHAIN GEOMETRY Fig 14 into a digital terrain model DTM for further processing in SMS and BASEplane The main application for this tool is to be found in combination with the Interpolation tool see chapter 0 In a first step the cross sections are interpolated with the Interpolation tool in order to get a smooth river topography In a next step the DTM is exported with the Export DTM for BASEplane tool on the menu bar choose Tools The generated DTM can be imported in SMS Although the file is of 2dm type it can be easily converted into scatter points DTM in SMS Then it can be used for the interpolation of the elevation information on any computational mesh Basically a computational mesh can be obtained directly from the Export DIM for BASEplane tool if the interpolated cross sections are chosen in a close and optimal distance to each other Nevertheless it is suggested to generate the
99. ch the shallow water equations are valid variety of sophisticated and automated tools allow fort the treatment of even difficult topographic situations 2 Scattered Data Module This module is used for interpolation of a group of widespread points into suitable meshes Interpolation can be caused by data of vertices measured field data or other sources delivered by the user This feature is intended for the setup of initial conditions or the examination of the existing model The program supports a broad range of different interpolation methods 3 Map Module GlS objects are used within SMS to illustrate topographic attributes SMS assigns properties and conditions to these GlS objects and constructs a mesh of elements This reduces the grid setup and development dramatically SMS imports TIFF and DXF data and uses them to develop and alter specific areas and model boundaries SMS 10 was used and tested during the development of the BASEMENT software After a year of experience it has proved to satisfy the needs concerning functionality and suitability The interactive interfaces provide a wide range of possibilities which simplify the process of grid adaptation and definition of the input data The visualization can be easily performed with SMS Scalar values like water depth or shear stress are rendered as contour plots while vector quantities as velocities are visualized in a scaled manner Another important feature is the possibility t
100. computational grid has great impact on the accuracy of the results and on the computational time needed for the simulation or the numerical time step respectively Generally a suitable VAW ETH Z rich Ul 3 2 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT mesh is dense at regions where strong changes in the flow occur and coarse in regions of lower interest Additionally the grid cells should not underlie strong deformations Usually the raw real world data comes in form of river cross sections or geographic terrain models e g from a GIS This elevation information has to be mapped onto a suitable mesh There are two types of computational grids structured and unstructured ones Structured grids consist of quadrilaterals and can be mapped onto a Cartesian domain They allow for simple data structures and efficient algorithms The mesh generation is relatively simple and can even be done manually However structured meshes are somehow unhandy for the representation of arbitrary topography data Unstructured grids are mostly composed of triangles and cannot be mapped onto Cartesian meshes They usually need more complicated data structures but are highly flexible for automatic mesh generation in complex geometries An unstructured grid is the most general case of a grid based discretization and is perfectly suitable for object oriented modelling BASEMENT is built on unstructured grids The computational grid consist
101. condition The BOUNDARY block within the BEDLOAD block defines the boundary condition for the bed load transport The bed load input is handled with a boundary condition which determines the transport capacity at the inflow cross section The ODown is the only downstream boundary condition available for sediment transport at the moment All sediment entering the last computational cell will leave the cell over the downstream boundary BOUNDARY type transport capacity string name Inflow_sed mixture single grain factor 1 0 VAW ETH Z rich U IV 3 5 5 Version 12 16 2010 User Manual BASEMENT TUTORIALS BOUNDARY type IODown string name Outflow 3 5 1 10 Bed load parameter The control parameters for the bed load simulation are defined in the PARAMETER block within the BEDLOAD block The bed load transport is computed with the Meyer Peter and Muellers mpm formula Since the imit_bedload_wetted tag is turned off the bed load is computed not only in completely wetted cells but in partially wetted cells as well The lateral transport caused by transversal slope in relation to the flow velocity is taken into account PARAMETER bedload factor 0 5 bedload_transport mpm theta Critic 0304 j limit bedload wetted off lateral transport on 3 5 1 11 Gravitational transport In the GRAVITATIONAL TRANSPORT block the parameters for gravitation induced transport are defined The gravitational transport can be limited
102. ctions Values discharge velocity water bed level concentration shear stress Result types max t min t integral time series with designed timestep Simulation times error estimation Execute Simulation VAW ETH Z rich Ul 4 1 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Elaborate results Flooded surfaces Flood trace Volume balance Hazard map Representative values Display Results Long Profiles Time Series Movies 2 D representation of topography level differences water depths flow field streamlines vorticity shear stress etc 3 D representation of topography Energy line Transport diagram Cross sections Ul 4 1 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 4 22 Scenario Examples Depending on the chosen scenario and on the available boundary conditions or i e topography data the approach for a successful simulation differs from case to case As there are different ways to reach a certain target the following activity diagrams just present possibilities but not a strict guideline An important part is always the grid generation Usually the raw topography data needs a lot of treatments manual correction interpolation adjustment of single elements etc until a suitable computational mesh can be generated Although programs for grid generation like SMS provide some powerful tools to manipulate mesh transfo
103. d to the single grain simulation just the modifications of the command file are pointed out Basically there is the possibility to use the grain size distribution to determine the bed friction in the FRICTION Block To simplify matters the friction is defined with the Strickler value Generally it is suggested to try both options and to choose the most suitable for your model purpose 3 7 1 1 Morphological parameters In the PARAMETER block important parameters for the morphological simulation are defined In multi grain simulations the thickness of the bed load control volume is an important calibration parameter This parameter influences significantly the grain sorting process PARAMETER control volume type constant control volume thickness 0 1 m 3 1 2 Grain size distribution The grain size distribution is discretized with six grain classes They have to be defined in ascending order from the smallest to the largest grain GRAIN CLASS diameters 15 15 44 82 150 mm j VAW ETH Z rich U IV 3 7 3 Version 12 16 2010 User Manual BASEMENT 3 7 1 3 Grain mixture TUTORIALS In the MIXTURE block the volume fraction of the different mixtures are defined The three river sections are considered with different sediment mixtures Furthermore a mixture for the inflow is defined MIXTURE name volume _ MIXTURE name volume MIXTURE volume MIXTURE name volume _
104. data the local data for many operations instead of having to reload them from memory or from caches of other processors In general better data locality is guaranteed if the work load is distributed statically among the threads instead of using a dynamic schedule Additional problems limiting the parallel performance may arise when OpenMP parallelized programs are executed on cc NUMA architectures with large number of cores due to general aspects of the underlying hardware architecture Chapman 2008 Ul 5 2 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 5 3 Parallelization with OpenMP 5 3 1 Overview As mentioned before parallel programming for shared memory systems bases on multi threading software concepts Thread programming can be done on a rather complex and time consuming low level by explicitly specifying and controlling all threading options In recent years high level concepts for thread based parallelization were developed which ease parallelization and do not require low level thread programming skills Among these high level concepts it can be differentiated between implicit parallelism using parallel programming languages or automatic parallelization by compilers and explicit parallelism where the developer controls the parallelism with support of parallel libraries and application programmer interfaces APIs In cooperation with leading software and computer enterprises a parallel
105. ded and the simulation can be started BASEMENT creates an initialization file as a hidden file in the users HOME directory bm ini which stores the present work directory and scenario name to ease the input procedure for repeated simulations of the same scenario According to the existence of a main control block either BASECHAIN 1D or BASEPLANE 2D the appropriate simulation will be carried out 4 3 4 Executing BASEMENT in batch mode Executing a simulation with BASEMENT normally opens the graphical user interface GUI and requires some input from the user e g to select the model data and to confirm warnings generated by the program at the start and during run time But BASEMENT can optionally be started without any graphical interaction and without user input This feature is especially useful if one or several models shall be run automatically via batch or script file VAW ETH Z rich Ul 4 3 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT But be aware that executing in batch mode requires special attention since significant warnings may be suppressed without being noticed It is recommended to study the generated log file after the simulation to check the program output for warnings which may have been generated during run time Executing in batch mode can be specified at the program start of BASEMENT using program arguments The following list of program arguments is supported at the moment and can b
106. dependent constraints by minimizing a local cost function of a piece wise interpolation Two examples of local cost functions are described in Bath 1995 3 4 1 4 Steiner triangulation A Steiner triangulation is a triangulation in which extra points are added to the original data to improve the quality of the mesh The additional points are called Steiner points The number of Steiner points must be limited limiting also the quality of the mesh 3 4 1 5 Non obtuse triangulation One of the most interesting types of Steiner triangulations is the triangulation without obtuse angles It is a Delaunay triangulation or constrained Delaunay triangulation and also minimizes the maximum angle and maximizes the minimum height Bern and Eppstein 1995 3 4 2 Algorithms 3 4 2 1 Sweep line algorithm The sweep line algorithm can be used to perform a first triangulation without any quality criteria It adds the points by x coordinate order and then connects them to all visible points of the convex hull of the existing triangulation 3 4 2 2 Divide and conquer For the divide and conquer algorithm the point set is divided in two half planes along the x axis Then each half plane is triangulated recursively and finally the two planes are merged AY Fig 6 a triangulated half planes b merged triangulation VAW ETH Zurich U II 3 4 3 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 4 2 3 Incremental Insertion algorithms
107. distributed in the hope that it will be useful but WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE See the GNU Lesser General Public License for more details You should have received a copy of the GNU Lesser General Public License along with this library if not write to the Free Software Foundation Inc 51 Franklin Street Fifth Floor Boston MA 02110 1301 USA Qwt Qt Widgets for Technical Applications BASEMENT v2 2 is based in part on the work of the Qwt project http qwt sf net CGNS CFD General Notation System cgnslib 4 5 http cgns sourceforge net VAW ETH Z rich Version 7 8 2011 U USER MANUAL m J 7 T m i i System Manuals BASEMENT This page has been intentionally left blank VAW ETH Zurich 7 I BASIC SIMULATION ENVIRONMENT alas BASEMENT System Manuals BASEMENT This page has been intentionally left blank VAW ETH Zurich User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Table of Contents 1 General Use 1 1 uy u E u usss 1 1 1 1 2 Product Delineation and Employment Domains 1 2 1 1 2 1 Product Delineation uota tese a USE I Ba 1 2 1 1 2 2 Employment rm 1 2 1 1 3 Processed Data Types and
108. drographs at the inflow boundary and water levels at the outlet boundary In general different special conditions can be applied by defining for instance the water level of a lake weirs steps etc 1 1 4 Source terms and local properties For every mesh element several characteristics can be specified for example not flown through cells mobile bed bed load potential k value roughness shear stress or others oources and sinks of water and or sediments might be added within the computational region U Il 1 1 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 2 Model input data 2 1 Topographic data sources The topographic raw data in the form of digital terrain information builds the fundamentals for grid generation and further numerical simulations using the BASEMENT software In the case of 1d simulation the raw data consists of recordings of river cross sections In a 2d or 3D model the raw data is built from point clouds height contour lines or a digital terrain model DTM Dependent on the assignment and its requirements most of the raw data usually gets collected by experts However there are some extensive topographic models with different quality available see e g the cross sections database from the Federal Office for the Environment BAFU and high resolution terrain models from swisstopo or Swissphoto The next sections provide short overview of different methods da
109. e specified in any order Command line Description arguments b BASEMENTiis run in batch mode without manual user input f filename The file flag f and the space separated filename argument specify the model filename which shall be executed The filename must be the full path including the name of the bmc file Please note No empty spaces are allowed to be part of the filename Display the version number of the BASEMENT executable doc This generates a reference documentation of all blocks and parameters in html format Example Type the following line to execute the model Scenario1 bmc in batch mode without user input BASEMENT vX X exe f d data Scenariol bmc b 4 3 5 Restart the simulation in BASEplane from a given solution In 2D simulations with BASEplane an improved and enhanced method for the restart from existing solutions from old simulation runs was implemented Such a restart file contains all relevant information and data which is needed for the continuation of an old simulation and therefore often needs a lot of disk storage These data are now stored in a binary format to reduce the needs for disk storage and to obtain smaller files For this purpose a standardized CFD format was chosen CGNS CFD General Notation System www cgns org This standardized data format additionally can be edited and visualized by different programs and simplifies data exchange between different programs A simp
110. e command flile J JJ 2 3 1 2 3 1 FO emet LT D 2 3 1 2o22 Bolle Em 2 3 1 2 3 3 Define the physical properties 2 3 1 2 3 4 One dimensional simulation 2 3 1 2 3 4 1 Define the geometry 2 3 2 2 3 4 2 Define hydraulic information 2 3 2 2 3 4 2 1 Define the upper boundary condition 2 3 2 2 3 4 3 Define the lower boundary condition 2 3 3 2 9 4 3 1 Deine i itial condiliglivu Qu k eo pev eo asss 2 3 3 2 3 4 3 2 Define default friction values 2 3 3 2 3 4 3 3 Declare parameters for hydraulic computation 2 3 4 2 3 4 4 CUMS OD Db ry uns 2 3 4 24 Perform hydraulic simulations 2 4 1 2 4 1 Perform steady flow simulation Thur1 2 4 1 2 4 2 Perform simulation of the floods Thur2 2 4 3 2 5 Complete the co
111. e some drawbacks of the 1 D simulation in the present case it is useful to define a main channel and flood plains as well as the bed bottom to which is limited the bed load transport In the figure below the flood plains are given by the part of the cross section not defined as main channel The soils by their indexes The keys 2 or 1 refer to the type of soil which 15 defined later in the command file Here we use only one soil for the whole bottom but it is also possible to add several soils of the same type or of different types as shown in figure Fig 3 Further different friction values can be defined for different parts of the cross section The active range should span from the left to the right dike Points outside the active range are simply ignored The graphical view of the cross section data helps to identify the correct point and set the ranges to the correct lateral node coordinates For convenience one can switch into the text editor mode of the input file by choosing from the Tools Menu the option Edit Raw Example Fig 3 Delimitation of cross section zones VAW ETH Zurich U IV 2 2 3 Version 12 16 2010 User Manual BASEMENT TUTORIALS Example name cs2 distance coord 0 049921 main channel range 60 523 117 128 Friction _coeFFicients s Friction ranges 10 233 60 523 50 523 67 274 57 274 109 984 109 984 117 128 117 128 167 344 node coords 10 233 377 395
112. ected variables VAW ETH Zurich U III 5 2 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE This page has been intentionally left blank U Ill 5 2 2 VAW ETH Z rich Version 12 16 2010 TUTORIALS of BASEMENT System Manuals BASEMENT This page has been intentionally left blank VAW ETH Zurich User Manual BASEMENT TUTORIALS Table of Contents NECI e uu a ip a sas 1 2 Hydrodynamics and sediment transport at the river Thur 2 1 MEME 9011 uuu l ul 2 1 1 2 1 1 I igie i te flojo P 2 1 1 2 1 2 1 lt 2 1 1 N N passa 2 1 2 22 Setting up the topography lile J J J T J J 2 2 1 2 2 1 GROSS SGCIIOlfS u oec ebat ed No diae ol fev esc oboe 2 2 1 2 2 2 Definition of different cross section zones 2 2 3 A2 2 2 4 2 2 4 Computation of water surface elevation 2 2 5 2 2 5 Characterisation of the ttnn 2 2 6 220 D lin eTIowingzonoSu ne vote Ra presi aa u up Rak ie 2 2 7 23 setting Up th
113. ed 2 1 1 2 1 3 Mrz h 2 1 2 2 1 4 SOB COS susunan kanaa 2 1 3 22 River related data sources 2 2 1 23 Characteristic quantities Of riverbed 2 3 1 24 Processing the raw data nio 2 4 1 2 4 1 TOBOOSDIV cost yu uu M ME Pe E ME MEM E ME 2 4 1 2 4 2 uum au NOM PER 2 4 1 2 4 3 A un una hu ee abi han assay 2 4 2 2b GISMMC E ass ooi uuu uu rece an ee eT 2 5 1 2 5 1 Administration of geographical data eet tet estet ee tus 2 5 1 2 902 Plaheassionnent Tor p usa eris 2 5 1 2 0 3 Interoperability and standard interfaces 2 5 1 3 Grid generation 3 1 nikod ctioiuuu uu l nre u QU u xu u Era Ru eR 3 1 1 3 4 Topographical input data 3 2 1 3 3 Mesuqualilyuyu uu uu 3 3 1 oup babet ust 3 3 1 O9 ANIDIGHOUS idt rei totale cue au ptio Pau ts 3 3 2 3 4 lssues on triangulation
114. ee of spatial and temporal compatibility of the sub domains Especially in case of combined 1 D and 2 D simulations the spatial extends and time step sizes can vary considerable Mainly two different coupling concepts are often encountered for the selection of the time step sizes of the sub domains e All sub domains are executed in a synchronous manner with an equal time step size To guarantee stable execution the chosen time step size global time step is set to the minimum time step size of all sub domains which is determined by stability conditions CFL criterion But due to the fact that the sub domains time step sizes can vary considerable such a restriction on the minimum time step size can lead to inefficient small time step sizes resulting in large computational efforts e In contrast all sub domains can be executed asynchronous with different time step sizes local time steps which are chosen according the sub domains optimal time step size This approach does not suffer the computational inefficiency due to small time step sizes But generally more synchronization efforts a required and data exchange between the sub domains requires interpolations and can become cumbersome especially for complex interfaces like junctions or bifurcations Here another approach is selected a local time stepping approach lying in between these concepts and combining efficiency and simplicity 6 5 2 Local time stepping approach
115. eeeseeeeeeeeeennneennn 4 3 1 4 3 4 Executing BASEMENT in batch mode 4 3 1 4 3 5 Restart the simulation in BASEplane from a given solution 4 3 2 5 Parallelization WEE ead Dem 5 1 1 5 1 1 Needs for parallel computing 5 1 1 5 1 2 Parallel computer architectures 5 1 1 5 2 Parallelization issues on shared memory systems 5 2 1 5 2 1 u uu m uD GD uu a ya phu 5 2 1 5 2 2 Factors influencing parallel performance 5 2 2 VAW ETH Z rich Ul i Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 5 3 Parallelization with OpenMP 5 3 1 9 99 Sl m 5 3 1 0 3 2 Characteristics or OpenMP uu uu u ines eu moe ie map a aide 5 3 1 5 3 3 Parallel directives in OpenMP 5 3 2 6 Model Coupling O VEO CUCU OI Ld 6 1 1 62 TY OCS reto dores isse k bs uyata SW kak uba 6 2 1 63 Coupling Mechanisms en u na hau u
116. een refinement The new vertex has to be connected on both sides of the edge with the opposing vertices of the neighbouring elements If one of the two resulting triangles still has a bad aspect ratio the element gets divided again In the same manner resulting in three new elements This is called the blue refinement It is the goal of the blue and green refinement to halve the longest side of the original triangle and whereas degeneration of the mesh in repeated mesh refinement steps is prevented Finally the red refinement connects all midpoints of the original edges which leads to four new elements VAW ETH Z rich U II 3 4 5 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING This page has been intentionally left blank U Il 3 4 6 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 5 Use of the grid generator of SMS 10 Obviously the pre processing before running a simulation needs a lot of work and effort The input for the numerical module consists of a computational mesh geometric and topographic attributes boundary conditions material properties e g friction factor etc A Suitable pre processing unit should therefore satisfy as much as possible of the following requirements 1 Grid generation 1 1 Import of referenced Image data TIFF and DXF 1 2 Capability to produce trianoular quadrilteral orids 1 3 Mapping of point clouds on a computational grid by interpolation 1 4 Tools
117. elements are too small the reaction of the system is very slow or even too weak to re establish the given targets The D Element depends on the change of the monitored variable and is used to quickly adapt the manipulated variables in case of a fast change More on the determination of correct PID coefficients can be found in the article by Fah and K hne 1987 Recommendations on how to choose the coefficients are given in the integrated help of the software VAW ETH Z rich Ul 7 3 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U 7 3 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT References Beffa C 2002 Integration ein und zweidimensionaler Modelle zur hydrodynamischen Simulation von Gew ssersystemen Int Symposium Moderne Methoden und Konzepte im Wasserbau ETH Z rich Oktober 2002 Chandra R Dagum L Kohr D Maydan D McDonald J Menon R Parallel Programming in OpenMP Chapman B Jost G van der Pas A 2008 Using OpenMP Portable Shared Memory Parallel Programming MIT Press Fah R K hne A 1987 Wasser Energie Luft eau nergie air Heft 5 6 p 93 1987 Miglio E Peretto S Saleri F 2005 Model coupling techniques for free surface flow problems Part Nonlinear Analysis Theory Methods amp Applications 63 2005 1885 1896 Kuhn B P
118. enMP does not support the whole range of threading concepts e g no support for semaphores for synchronization U I 5 3 1 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT The source code can be compiled as serial program without support of OpenMP compiler directives treated as comments This may ease debugging of new implemented application features Tab 1 OpenMP parallelization pro and contra 5 3 3 Parallel directives in OpenMP The basic parallelization construct in OpenMP is the so called parallel region The source code placed within a parallel region is executed in parallel on a number of threads At the end of a parallel region an implicit barrier is automatically set to synchronize the threads Parallelization with OpenMP serial code parallel region pr agrra onp parallel Codebl ock 7 Codebl ock serial loop for work sharing construct pragma omp parallel for for i 0 i lt n i Codeblock serial tasks sections work sharing construct w for 1 0 ien i Codeblock onp parallel section section Calculat eDomainA j section w Calculat eDomainA Calculat eDomainB DomainB Calculat eDomainB O Fig 12 Compiler directives for basic parallelization constructs in OpenMP Ul 5 3 2 VAW ETH Z rich Version 7
119. engineering of existing codes Floris 2dmb has been carried out while merging it with modern and new numerical approaches From a software technical point of view an object oriented approach has been chosen with the aim to provide reusability reliability robustness extensibility and maintainability of the software to be developed After four years of designing implementing and testing the software system BASEMENT has reached a state to go public The documentation at hand confirms the invested diligence to create a transparent software system of high quality The software in terms of an executable computer program and its documentation are available free of charge It can be used by anyone who wants to run numerical simulations of rivers and sediment transport either for training or for commercial purposes VAW ETH Z rich Version 6 3 2010 System Manuals of BASEMENT PREFACE The further development of the software tends to new approaches for sediment transport simulation carried out within the scope of scientific studies on one hand side On the other hand effectiveness and composite modelling are the goals On either side a reliable software system BASEMENT will have to meet expectations of the practical engineer and the scientist at the same time em Prof Dr Ing H E Minor Member of the steering committee of Rhone Thur Project 2002 2007 Director of VAW 1998 2008 October 2006 VAW ETH Z rich Version 6 3 2010
120. ent choice of Blocks and Tags is valid Fig 2 In case of errors the Block and its parent Blocks in the Input Structure are red In case of warnings the Block and its parent Blocks in the Input Structure are brown Blocks without warnings or errors are green Selecting a red or brown Block in the Input Structure will show all errors and warnings as Validation Messages An Input without red messages has no errors and can be used for simulation 2 2 3 1 Mandatory Blocks and Tags Certain Blocks and Tags may be mandatory to define If a mandatory Block or Tag is missing an error message like Block Error Tag XY is mandatory but missing is displayed until the Block or Tag is defined 2 2 3 2 Default Values Some Tags have default values They are usually not mandatory to define Defining a Tag with an associated default value will show the specific Tag value in the Input Field for the Tag where it can also be changed to a user defined value 2 2 4 Use the Built in Help Function Every Block and Tag is documented within the Reference Manual R IV This same information is also available within the BASEMENT Editor Clicking on the Information button with a question mark Fig 2 will produce a pop up window with a description of the usage and some examples The Information button for a block is located at the top of the main view near the Blocks name For a Tag the button is to the right of the precise value of a Tag The documentation for
121. eria Empty circle criterion a Delaunay triangulation or constrained Delaunay triangulation Is obtained In this case a global optimum is reached Minimize the maximum internal angle for both triangles gives MinMax triangulation only locally optimized Optimize a local cost function leads to data dependent triangulations only locally optimal triangulation Bath 1994 Other properties that can be optimized with edge flipping are for instance vertex degree or total edge length but a global optimum is not guaranteed If the algorithm is used to obtain a CDT the constrained edges simply are not tested because they can not be swapped 3 4 2 5 Edge insertion This algorithm solves the problem of minimizing the maximum angle in time O n log n exactly Like the edge flipping algorithm it starts from an arbitrary initial triangulation It incidentally inserts candidate edges on a vertex of a worst triangle The crossed edges are removed and the remaining regions are re triangulated If the triangulation gets worse the added edge is rejected This algorithm can also be used to find an interpolating surface with minimal slope in time Bern and Eppstein 1995 3 4 2 6 Blue red and green refinement This is another popular method for mesh refinement Basically an element with an aspect ratio out of bound gets divided into two elements by inserting a new vertex on the midpoint of the longest edge This is the so called gr
122. etailed overview of all possible output types values format types and more is given in the Reference Manual IV RIV Command and input files OUTPUT output time step 2000 console time step 100 SPECIAL OUTPUT format sms type node centered values depth wse velocity deltaz z node output time step 20000 SPECIAL OUTPUT format tecplot binary yes type element centered values z element deltaz output time step 80000 SPECIAL OUTPUT type balance balance values sediment timestep output time step 1000 SPECIAL OUTPUT type boundary history boundary values Q Qsed history one file yes output time step 1000 U IV 3 5 8 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 6 Perform morphological simulation with single grain bed load transport Open the command file Flaz morphology single grain bmc either by double clicking or via the menu of the BASEMENT GUI File gt Open Command Run the simulation with the Run button of the BASEMENT window Be aware that the mesh command file and all other input files have to be in the same folder The defined outputs are now generated in the same folder as the command file The output files with the ending so can be visualized using the program SMS The bed elevation after the flood event is shown in Fig 24 Two cross sections are defined Fig 24 and the bed elevation before and after t
123. etersen P Kuck amp Associates Inc OpenMP versus Threading in Manferdelli J L Govindaraju N K Crall C Challenges and Opportunities in Many Core Computing Proceedings of the IEEE May 2008 Online reference of OpenMP freely available at http www openmp org Sanders B 2008 Integration of a shallow water model with a local time step Journal of Hydraulic Research 46 4 466 475 VAW ETH Z rich U References Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U I References VAW ETH Z rich Version 7 8 2011 ull PRE PROCESSING of BASEMENT System Manuals BASEMENT This page has been intentionally left blank VAW ETH Zurich User Manual BASEMENT PRE PROCESSING Table of Contents 1 General TI ReQq liremen l uu au Saa 1 1 1 1 1 1 Projeti belium E 1 1 1 i a M M ML MM EM 1 1 1 1 153 POUNGA eae 1 1 2 1 1 4 source Terms and local properties occa e ero bep e bee tal 1 1 2 2 Model input data 2 1 Topographic data sources 2 1 1 ZA Terrestrial data or surveying with differential GPS 2 1 1 2 132 Oficial TOMO GTA MC SUNY SV uuu tosta bes mencio anc
124. f parallelisation is completed The current implementation of the code includes the OpenMP interface which allows for parallel execution of the basic computation loops In other words the software is now able to exploit the power of current multi core processors with a VAW ETH Z rich Version 6 3 2010 System Manuals of BASEMENT PREFACE convincing speedup Furthermore the revision of some data structures and output routines as well as the application of an optimised compiler led to a reduction in execution time Concerning sediment transport the one dimensional model BASEchain now supports the modelling of fine material either as suspended or bed load Also the advanced models for boundary conditions are worth mentioning On the one hand it is now possible to model domain boundaries with momentum and on the other hand special boundary conditions inside the computational region such as a weir or a gate are implemented The fact that the version 1 4 of BASEMENT is also available for the Linux operating system the first time rounds off the new additions and features of the software package at hand oummarised one may say that the release 1 4 of BASEMENT is a major release due to all the different kinds of changes but it s still a minor release concerning the new features let s call it a major minor release We are looking forward to Version 2 0 of BASEMENT which is planned for next year D Vetsch Project Supervisor October 20
125. fixed bed can be defined either with a separate mesh file containing the fixed bed elevations or with specific fixed bed elevations for some selected nodes Furthermore a fixed bed can be implemented in the SOIL DEF block chapter 3 5 1 5 If there is no layer defined a fixed bed will be assumed In any case a fixed bed is assumed below the last layer In this tutorial the FIXED BED block is used as an example to define a fixed bed for a single node This can be used to consider a big stone for example A fixed node node id 8956 is implemented by giving zb fix a value smaller or equal to 100 U IV 3 5 4 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS FIXED BED type nodes 8956 node ids zbo fix eq pO 3 5 1 7 Assignment of the defined soil types The soil types defined in the SOIL DEF blocks section 3 5 1 5 are assigned to the elements of the mesh by the material index SOIL ASSIGNMENT type index table index 1 2 3 4 5 6 7 8 9 10 11 12 soil soil roughness elements soil fix soil fix soil widening soil fix soil widening soil alt bars S ll fix IBOLI dux SOLL TIK Sol Fix 20 gOIl 21x59 3 5 1 8 Initial condition The initial bed elevation is defined in most cases as the actual topography If there is no INITIAL block defined the initial bed elevation will be automatically set to the bed elevation in the computational mesh file 3 5 1 9 Bed load boundary
126. for revitalisations or protection measures where the consequences of the interventions have to be evaluated Identification and quantification of dangers for the development of danger maps or of protection and emergency measures considering the flow behaviour and sediment deposition both inside and outside of the main channel as well as erosion danger and consequences of debris flows and dam breaks VAW ETH Z rich U I 1 2 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 1 2 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 1 3 Processed Data Types and Capabilities 1 3 1 Processed Data Types The raw data can be divided into three groups topographic data particularly elevation models and cross sections hydrologic data time series of flow discharge water levels or concentration of suspended sediments velocity profiles granulometric data grain size distributions from water sediment or line samples 1 3 2 Capabilities BASEMENT has the following fundamental capabilities Simulation of flow behaviour under steady and unsteady conditions in a channel as well as its transition Simulation of sediment transport both bed load and suspended load under steady and unsteady conditions in a channel with arbitrary geometry Simulation of erosion Choose between different approaches e g choice of prob
127. ge but often these programs are somehow limited to specific applications and data formats It is therefore recommended to specify the desired data format and resolution in advance to avoid unnecessary repetitions More detailed information about grid generation is given in the next chapter 2 4 2 Hydrology The hydrologic raw data for discharge and water levels usually has a non uniform resolution in time Often the measurements are indexed with date and time For the simulation module the time series have to be converted to a system with standard units e g seconds In an easy case the converted data can directly be used as a boundary condition The simulation module will then interpolate the desired values to the actual computational time Further modifications may be necessary e g just some time slots have to be simulated or If the main processes for a phenomenon like sediment transport occur at no more than a certain water discharge VAW ETH Z rich U Il 2 4 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 2 4 3 Grain size distribution As mentioned earlier the granulometric composition of the erodable material gets measured by a line sample or a sieve analysis and results in a grain size distribution grain diameter versus weight percentages relative to the total sample weight For the simulation this distribution has to be discretized and desired grain classes have to be determined Each grain class is defined b
128. h velocity depth max velocity output time step 10000 SPECIAL OUTPUT format tecplot binary yes type element centered values max depth max wse max velocity output time step 80000 SPECIAL OUTPUT type balance balance values timestep output time step 500 SPECIAL OUTPUT type boundary history boundary values Q history one file yes output time step 500 VAW ETH Z rich U IV 3 4 5 Version 12 16 2010 User Manual BASEMENT TUTORIALS Open the command file Flaz_hydraulic_instationary omc either by double clicking or via the menu of the BASEMENT GUI File gt Open Command Run the simulation with the Run button of the BASEMENT window The maxima values of the flow depths and flow velocity vectors can be visualized using SMS as shown in Fig 23 Fig 23 Maximal flow depth and flow velocity vectors of the unsteady flow simulation 3 4 3 Calibration of the hydraulic model The hydraulic model can be calibrated for example based on flood level marks by comparing the modelled water surface elevations with the flood level marks Usually the calibration parameter is the bed roughness introduced with the Strickler value The calibration procedure may need several adjustments and is an iterative process The demonstration of the calibration is not part of this tutorial It should be mentioned that it is important to have a calibrated hydr
129. he private sector Most often the programs were tailored for a specific application and adapted to fulfil costumer needs Consequently the software grew in functionality but with little documentation Due to limited temporal and personal resources to absolve an according project a single point of knowledge concerning the details of the software was inevitable in most of the cases In 2002 the applied numerics group of VAW was invited by the Swiss federal office for water and geology BWG nowadays Swiss Federal Office for the Environment FOEN to offer for participation in the trans disciplinary Rhone Thur project With the idea to build up a new software tool based on the knowledge gained by former numerical codes while eliminating their shortcomings and expanding their functionality a proposal was submitted The bidding being successful a partnership in terms of co financing was established By the end of 2002 a newly formed team took up the work to build the so called BASic EnvironMENT for simulation of environmental flow and natural hazard simulation BASEMENT From the beginning the objectives for the new project were ambitious developing a software system from scratch containing all the experience of many years as well as state of the art numerics with general applicability and providing the ability to simulate sediment transport Additionally professional documentation is a must As to meet all these demands a part wise re
130. he Grid File Editor is opened a new window pops up see Fig 5 In the left part of the window a list of all cross sections is shown where the cross sections can be seen and selected In the right part of the window a visualization of the whole subdomain with all cross sections is drawn and new cross sections can be created with the Add Block option The subdomain view allows zooming and shifting of the display and the selection of a specific cross section by double clicking If a cross section is selected then the view changes to the cross section view G D BASEMENT PROJEKTE Coupling V1 Aarc1 topo korrigiert ncutr bmg BASEMENT 1D grid file cditor BASECHAIN GEOMETR Y New Tags Blocks 1 avaisi Subdamain View List af all 4 Zocor In Out mouse wheel Gross Sections i Shift Display dick hald y CROSS_SECTION Pick Cross Section double click Fig 5 Grid File Editor Subdomain View The real usually curved shape of the stream can only be illustrated if all cross sections are geo referenced and if all corresponding data is set the orientation angle and the left point global coordinates must be set for each cross section If these data are not given than the cross sections are drawn along a straight line VAW ETH Z rich U Ill 4 1 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE This page has been intentionally left blank U Ill
131. he command file reference provides detailed information on the meaning of input parameters This gives way to a clearer model setup compared to the rather fault prone manual text editing which is still available and also accessible through the GUI Another main feature of the new GUI is the editing of the topography for BASEchain Besides the GUI based setup interpolation and thinning out of model cross sections a graphical viewer helps the user to check the configuration and subdivision For this reason the new version VAW ETH Z rich Version 6 3 2010 System Manuals of BASEMENT PREFACE of BASEMENT comes with its own topography file format for BASEchain The new format has a clear structure similar to the style of the command file Moreover the visualisation of actual results during a simulation with BASEviz has been Improved and is now more interactive i e the simulation can be paused continued or the variable shown can be switched Other improvements concern computational efficiency and sediment transport especially gravitational bed load transport Please refer to the release notes in the section introduction and installation of this manual for further details about new features and bug fixes The software system BASEMENT in its current version 2 0 has reached the point to be termed as a state of the art numerical modelling tool for flow and sediment transport in rivers The incorporated well established or new numerical approaches
132. he flood event are compared Fig 25 The result file in the tecplot format can be visualized by the use of the program Tecplot As an example the morphological changes deltaz are shown in Fig 26 bed elevation m a s l 1713 0 1712 0 1711 0 1710 0 1709 0 1708 0 1707 0 1706 0 Qs2 Fig 24 Modeled bed elevation z_bed and two cross sections defined in the widening part VAW ETH Zurich U IV 3 6 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS 1713 ree QS 1 before flood event _ after flood event E 17114 c 1710 S 1709 1708 1707 0 width m 1712 N bed elevation m a s l k aaa N 1705 l l l l l l 0 10 20 30 40 50 60 70 width m Fig 25 Comparison of the river bed before and after the flood event in cross section QS 1 and QS 2 P kE EA NN ANNI jJ i VV n af Ti NV Z7 deltaz m 1 0 8 0 6 0 4 0 2 0 0 2 0 4 0 6 0 8 1 Fig 26 Changes of the morphology deltaz due to the flood event with the single grain model The red colour range represents deposition and the blue colour range shows erosion U IV 3 6 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 7 Morphological simulation with multi grain bed load transport In order to avoid needless duplication compare
133. he original intentions of the parties as closely as possible and maintain the economic balance between the parties 13 Applicable law This Agreement as well as any and all matters arising out of it shall exclusively be governed by and interpreted in accordance with the laws of Switzerland excluding its principles of conflict of laws 14 Jurisdiction If any dispute controversy or difference arises between the Parties in connection with this Agreement the parties shall first attempt to settle it amicably Should settlement not be achieved the Courts of Zurich City shall have exclusive jurisdiction This provision shall only apply to licenses between ETH Zurich and foreign licensees By using this software you indicate your acceptance License version 07 08 2011 VAW ETH Z rich Version 7 8 2011 System Manuals of BASEMENT LICENSE AGREEMENT THIRD PARTY SOFTWARE COPYRIGHT NOTICES The Visualization Toolkit V TK Copyright c 1993 2008 Ken Martin Will Schroeder Bill Lorensen All rights reserved Redistribution and use in source and binary forms with or without modification are permitted provided that the following conditions are met Redistributions of source code must retain the above copyright notice this list of conditions and the following disclaimer Redistributions in binary form must reproduce the above copyright notice this list of conditions and the following disclaimer in the documentation and or other m
134. hed by the flood For this purpose the cross section geometry and can be taken from the topography file and the water surface elevation from the main output file Alternatively a monitoring point of type geometry could be used z m cross section 11 od level 379 378 maximum water surface 377 376 375 374 373 372 371 370 369 elevation 0 50 100 150 200 250 300 350 y m U IV 2 4 6 Fig 9 Example of resulting water surface elevation VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 5 Complete the command file for bed load transport After copying the files from simulation 2 in a new folder the command file must be completed with information about bed load which is grouped in the block MORPHOLOGY The new command file is renamed Thur3 bmc In the block BASECHAIN 1D chose MORPHOLOGY and press Add Block Go in the block MORPHOLOGY 2 5 1 Define the bed material The simulation is executed with a single grain class with mean diameter 2 5 cm This means that you have to define one grain class and one mixture Add a block of type GRAIN CLASS and one of type MIXTURE In the GRAIN CLASS block add the diameter In the MIXTURE block add the name and the volume fraction BEDMATERIAL GRAIN CLASS diameters 25 MIXTURE name unique volume fraction 100 gt VAW Z rich U IV 2 5 1 Version 12
135. hem The phenomena to be considered have to be chosen as well as there are at the moment dam break bed load suspended load debris flow mobile bed erosion collapse pollutants etc 1 1 2 Input data As mentioned in the introduction there are three main types of data to be provided for a simulation topography hydrology and sediment data All data has to be transformed in a certain way to satisfy the input specifications of the main computation program The precise specifications are available in the reference manual 1 1 2 1 Topography Computational mesh The most important and most laborious to achieve input is the retrieval and setup of the computational mesh It is based on the real world topographic data At the end of the pre processing task a grid in a defined shape and format is available for the simulation module This mesh can be generated in different ways The topographical raw data may come from a cluster of points described by three dimensional coordinates digitized contour lines break line polygons or cross sections and probably is furnished in different file formats which have to be interpreted and transformed For a 2d simulation in a first step a TIN Triangulated Irregular Network has to be generated Then this mesh has to be modified and refined in order to satisfy the special mesh qualities needed for stability of computation VAW ETH Z rich U Il 1 1 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSI
136. ic condition at the boundary is set by the use of a hydrograph and a corresponding slope The normal slope is used in order to calculate the normal flow depths and the normal flow velocities at the boundary and can be considered as a calibration parameter BOUNDARY type hydrograph string name Inflow file Inflow stationary txt slope 10 0 per mill The hydrograph is saved in a text file nflow stationary txt in which the first column is the time and the space separated second column is the discharge Fig 18 As a first step a steady inflow hydrograph is an appropriate choice in order to test the mass conservation of the model After a certain run time depending on the size of the model domain the outflow should counterbalance the inflow There should be no uncontrolled mass loss within the model domain Usually the discharge is taken as the mean annual discharge or the beginning discharge of a flood event In this case a steady discharge of 50 m s is chosen in order to be able to continue later on with a flood hydrograph which starts in this range VAW ETH Z rich U IV 3 3 5 Version 12 16 2010 User Manual BASEMENT TUTORIALS uu Av Inflow_stationary txt Notepad Jy Es File Edit Format View Help f Stationary hydrograph ae s _ 5 a 3600 50 Fig 18 Stationary hydrograph file saved as Inflow_stationary txt The outlet boundary condition is defined across the predefined string Outflow The norm
137. ility satisfactory quality and fitness for a particular purpose warranty of accuracy of results of the quality and performance of the Software warranty of noninfringement of intellectual property rights of third parties 8 Liability ETH Zurich disclaims all liabilities ETH Zurich shall not have any liability for any direct or indirect damage except for the provisions of the applicable law article 100 OR Schweizerisches Obligationenrecht 9 Termination This Agreement may be terminated by ETH Zurich at any time in case of a fundamental breach of the provisions of this Agreement by the licensee 10 No transfer of rights and duties Rights and duties derived from this Agreement shall not be transferred to third parties without the written acceptance of the licensor In particular the Software cannot be sold licensed or rented out to third parties by the licensee 11 No implied grant of rights The parties shall not infer from this Agreement any other rights including licenses than those that are explicitly stated herein 12 Severability If any provisions of this Agreement will become invalid or unenforceable such invalidity or enforceability shall not affect the other provisions of Agreement These shall remain in full force and effect provided that the basic intent of the parties is preserved The parties will in good faith negotiate substitute provisions to replace invalid or unenforceable provisions which reflect t
138. iment coming in as is transported out of the first element BOUNDARY type IOUp string upstream U IV 2 5 4 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 5 6 Generate a geometry file To see how the geometry of cross section 14 changes during the flood add a special output to the OUTPUT block OUTPUT output time step 1000 console time step 1000 SPECIAL OUTPUT type monitor output time step 1000 cross sections CS14 geometry time VAW ETH Z rich U IV 2 5 5 Version 12 16 2010 User Manual BASEMENT TUTORIALS This page has been intentionally left blank VAW ETH Z rich U IV 2 5 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 6 Perform bed load simulation Thur 3 Run the file Thur3 bmc When the simulation is terminated look at the Thur3out file take the columns of distance and mean Bottom level of the start and end situation and make a longitudinal profile of it Additionally open the topology file of cross section 15 and plot the old and new geometry of the cross section mean bottom level initial situation simulation result 0 500 1000 1500 2000 2500 distance m Fig 11 Longitudinal profile of mean bottom level cross section 14 initial situation simulation result Fig 12 Cross section Obviously this is only a first run for exercise This computation now needs calibration and valid
139. ines its own local time step size as its level L multiplied with the base time step size Af L At The execution of the sub domains takes place in loops over level sequences One loop sequence of the LTS synchronization is sketched in Fig 18 for three sub domains with different time step sizes At gt At gt At and levels L i legend A B gt data exchange B is 1 1 data exchange mmi e data exchange with L 2 t D intermediate storage BE A L 4 L 1 nn mmm n ua m n Blass sub domains B L 2 L 4 gt b U sx time t C L 1 sequence of levels L N 7 Fig 18 LTS synchronization for 3 sub domains with different time step sizes The sub domain with the smallest time step size determines the base time step Sub domains A and B run for multiples of 4 and 2 of the base time step size For example in case that the maximum level of a sub domain is 8 a level sequence of m 1 2 1 4 1 2 8 is executed where m equals the present level of the loop Each sub domain is executed only if its level L is smaller or equal to the present level m These sub domains are then advanced for a time step size of At L At Data exchange between adjacent sub domains takes place only when the sub domains have reached a common level If adjacent sub domains have different time levels then the exchanged data must
140. ing of the BASEMENT software is described in the part Introduction and Installation of this manual Further details concerning the GUI of BASEMENT are explained in the user manual UIII 4 3 2 Executing BASEMENT on Microsoft Windows When running BASEMENT under Microsoft Windows operating system the easiest way to start a simulation is by double clicking on the command file ending with bmc Otherwise the program can be executed choosing the Run command for the Windows etart menu or by double clicking the executable file in Windows Explorer After running BASEMENT will open the graphical user interface where the command file can be loaded and the simulation can be started BASEMENT creates an initialization file in the users HOME directory bm ini which stores the present work directory and scenario name to ease the input procedure for repeated simulations of the same scenario According to the existence of a main control block either BASECHAIN 1D or BASEPLANE 2D the appropriate simulation will be carried out 4 3 3 Executing BASEMENT on Linux BASEMENT runs as a console application without screen graphics output On LINUX you open a console and type BASEMENT vX Y replace X Y with current version number to start the executable if no environment variables have been set change into your bin directory of the installation path After running BASEMENT will open the graphical user interface where the command file can be loa
141. ituated on a straight line between its two neighboured nodes considering the given tolerance If this is the case the node is removed from the profile see Fie 10 Nodes which are used as fixpoint or which are explicitly referenced by a slice index range are excluded from the algorithm and cannot be removed automatically node rernowe d if l distance to straight line diztarice tolerance Fig 10 Schematic sketch of node removal Guess Active Range This tool provides a definition of the active range where it is not yet defined For this purpose the lowest point of the cross section is searched and then the highest points to the left and the right of it usually the dam crests are set as limits of the active range The definition of the active range can always be changed manually by the user in the interface As an example on how the active range is set see Fig 11 4 3 4 Guess Fixpoints This tool provides the definition of some fix points which are needed for a correct interpolation of new cross sections between existing cross sections So this should be done before an interpolation is executed The fix points are displayed in red The points which are automatically set as fix points are e The limits of soils e The limits of the main channel e limits of the active range e The midpoint of the main channel VAW ETH Zurich U Ill 4 3 3 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE
142. iver Systems 7 1 OCUIG UI ON Eee 7 1 1 TZ Concept of Flow Control beu u 7 2 1 1 2 1 Monitored Via Dle EOM 1 2 1 7 2 2 Manipulated Variable a nnns 7 2 1 Ge Controller Types ve ceo od voted e Eee pavo EU asus 7 3 1 7 3 1 iP 7 3 1 UI ii VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT List of Figures I 2 1 Fig 2 Modules and their Components 3 1 Fig 3 The Meta Model fusion of real world data with abstract numerical considerations 3 2 1 Fig 4 Discrete Representation of the Topography within BASEchain 3 2 3 Fig 5 Discrete Representation of the Topography within BASEplane 3 2 4 Fig 6 Activity diagram generate computational mesh 4 2 1 Fig 7 Activity diagram Sediment balance in a river 4 2 2 Fig 8 Activity diagram Flood 1 2 D 4 2 3 Fig 9 Activity diagram Debris flow 2 D
143. iver Thur U IV 2 1 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT 2 22 Setting up the topography file 2 2 4 Cross sections TUTORIALS The data of the topography are available in the form of cross section measurements where each measured point is given by its x y and z coordinates This is an extract from the raw data x 69 69 69 69 69 69 69 69 69 69 69 69 69 8578 504 8578 494 8578 32 8577 929 8578 081 8578 533 8578 56 8578 612 8578 86 8579 201 8579 323 8578 937 8579 208 a 272450 272446 272444 272441 272439 272437 272434 272431 272429 272426 272424 272422 272421 223 999 286 889 244 229 366 522 064 526 56 91 645 376 374 373 373 372 371 370 370 370 370 370 370 370 841 991 748 229 207 544 869 766 401 388 617 341 436 These data have to be separated in groups belonging to one cross section and then transformed in a way to have a z y relation where the smallest y is the extreme point on the left river side Example Q H OK 125 14 16 17 18 455081097 349044033 134094857 4803278107 241452785 123103693 23346129 41786604 57016281 53240603 34176138 09961488 74552432 VAW ETH Z rich Version 12 16 2010 376 376 ENAN 378 378 378 377 377 376 376 376 376 375 3 5 264 327 804 133 238 227 965 395 664 221 21 215 99
144. ize simulation results during run time To activate the visualization tool a SPECIAL_OUTPUT block of BASEviz type must be created within the parent OUTPUT block Then the BASEviz window will appear automatically by starting the simulation The output can be visualized interactively using the mouse and keyboard keys according to the legend shown in the BASEviz window see Fig 15 and Fig 16 The view can be changed and the displayed variables can be selected This visualization tool allows to easily check for a correct simulation setup and to stop a simulation run if some evident problems arise Furthermore it is possible to dump the rendered images from the visualization window in a JPEG image for a given time interval e BASEviz for 1 D simulations with BASEchain All 1 D cross sections with its multiple slices are plotted one after the other along the x axis The water elevation is plotted within each cross section slice according to its present value H BC 2 Thur Altikon JL x water depth m 2713 31 BASEchain vtk help use left mouse button to rotate viev middle mouse button to shift viev use right mouse button wheel to zoom vlev h toggle thb help tex D reset vlev or q to quit the simulatio w turn on wireframe styk 5 turn on surface styk g toggle grid line pause 5 show water deptr 6 show water elevatiol 7 show bedz change 8 show
145. key factors influencing the speedup and according parallel programming aspects are briefly discussed in the following section e Parallel overhead Parallel overhead is created at many locations and times in the program Threads must be forked and joined loop iterations must be divided among threads and threads must be synchronized In the worst case the parallel overhead can even exceed the performance gains from parallel execution This is especially a problem in case of small loops with small workload e g in case of initialisation loops Such loops are not suited for parallelization and should better be executed in serial or if possible should be integrated into larger loops For simulations with loops of rather small workload but very high number of time steps it is important to prevent parallel overhead from frequently joining and forking threads This was achieved in Basement by integrating the whole time loop into a single parallel region The significance of parallel overhead in a parallel application depends largely on the computational costs of the simulation domain Simulations with high computational costs e g simulations with large numbers of elements are less negatively affected U 5 2 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Coverage In order to obtain a good parallel scalability it is important to parallelize large portions of the code resulting in a so called high
146. l BASEMENT PRE PROCESSING 2 4 Processing the raw data It was shown in the previous sections that the numerical model needs some specific characteristic values which usually are not given directly by in situ measurements Often some experience in handling computational simulation models is necessary to reproduce the natural conditions in an adequate way and obtain realistic results 2 4 1 Topography The topographic raw data for 1d or 2d simulations comes in the form of cross sections or by a digital terrain model DTM For a 1d model cross sections are mostly of accurate quality and need just few corrections and adaptations However most DTM s serving as a base for a 2d model need an elaborate revision because of the surface triangulation the resolution of the DIM and the computational grid are not congruent e g areas of lower interest shall have a coarse grid to reduce computational effort the DTM usually has a uniform point density the course of water bodies is not continuous or cross sections are not complete e g data only available up to the water level passages are not omitted e g bridges modelling and representation of buildings is not a priori known e g height of buildings retention volume flow resistance relevance of waste edges and artefacts are costly to determine e g small walls temporary dumpsites hedgerows etc The choice of software resources for processing the topographic raw data is hu
147. lass relative to the total mass of sublayer Sub default values according to the pem grain size distribution properties D mass fraction of the e grain class relative to the total mass of the active layer possible default values according to line samples if available The listed attributes are mostly not completely determinable directly For example the equivalent sand roughness K based on Nikuradse is an experimentally obtained value for the flow resistance of different kind of surfaces In the case of a more complex soil structure k may consist of several components Its actual value has to be determined by a calibration of the numerical model The same holds true for the critical value Z e which defines the beginning of movement at the soil surface This value is affected by the character of the bed surface like natural cover or sealing at farmlands Without special conditions the critical value can be estimated via the grain size distribution The mass fraction D sub of grain class g in sublayer Sub has to be derived from an experimental grain size distribution using a sieve analysis The material to be sieved may come from a near surface sample take e g by daggering or a drill hole The granulometric composition directly at the surface can be estimated by a line sample Accordingly the corresponding mass fractions D in the active layer can be determined U II 2 3 2 VAW ETH Z rich Version 10 22 2009 User Manua
148. le Data Viewer for CGNS files is the adfviewer which can be found on www cgns org The restart from an old solution is possible for the hydraulic computations bed load transport computations and suspended load computations Using this new file format the possibilities to continue a simulation from a given solution were enhanced It is possible to continue a simulation not only from the last point in time of the old simulation run but also from different times of the old simulation This can be very helpful Ul 4 3 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT especially for large simulation runs with long durations For example if there was an error in the inflow hydrograph at a point in time than the simulation can be restarted shortly before the time when the error occurred with a corrected hydrograph and without having to repeat the whole simulation from beginning VAW ETH Z rich Ul 4 3 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 4 3 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 5 Parallelization 5 1 Overview 5 1 1 Needs for parallel computing Parallel computing is currently getting increasingly important for numeric scientific and engineering applications and this trend will become even more significant in the near future Where parallel computers in the past were mainl
149. lem matched solver algorithms VAW ETH Zurich U I 1 3 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U I 1 3 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 2 System Overview At the current stage of development the software system consists of the numerical subsystems and the different interfaces to the infrastructural software such as pre and post processors The core of BASEMENT consists of the numerical solution algorithms comprised in the appropriate modules Pre and post processing can be performed with independent products using a well defined common interface The flexible software design enables a future adoption to a common database for input and output data Numerical Models 1d 2d Input Output Pre Post Processing Processing Hydrology Sedimentology and Soil Parameters Topography GIS legend Numerical Subsystems Infrastructural Software External Data mk provided interfaces to infrastructure Fig 1 System Overview VAW ETH Z rich Ul 2 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U 1 2 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 2 1 Numerical Subsystems The core of the software system consists of the numerical subsystems which ac
150. les is given A more detailed description can be found in the reference manual BASEMENT Saint Venant Equ 1d Shallow Water Equ 2d Navier Stokes Equ 3d Closure Conditions Scalar Transport Equ Suspened Sediment Transport Bedload Sediment Trsp Lateral Transport Gravity Induced Transport a Fig 2 Modules and their Components VAW ETH Z rich U I 3 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U I 3 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 3 1 Mathematical Physical Modules The behavior of the fluid hydraulics can be explained with physical models namely the conservation of mass and momentum Theoretically it is possible to resolve the mathematical problem up to small scale phenomena like turbulence structures In a natural problem however it is mostly impossible to determine all boundary and the exact initial conditions Furthermore the computational time needed to solve the full equation system is increasing very fast with higher spatial and temporal resolution Therefore dependent on the problem simplified mathematical models are used In three dimensions the flow and pressure distribution are completely described by the Navier Stokes equations These equations can only be solved numerically as analytical solutions exist only for some strongly simplified problems
151. llowing general structure PROJECT DOMAIN multiregion Flaz PHYSICAL PROPERTIES BASEPLANE 2D region name Flaz GEOMETRY HYDRAULICS MORPHOLOGY ae OUTPUT j j 3 3 1 Project In this block the project name the author and the date will be set PROJECT title e 2D Tutorial author LV date 23 11 2010 VAW ETH Z rich U IV 3 3 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 3 2 Domain The DOMAIN block includes all necessary blocks for a simulation DOMAIN multiregion Flaz PARALLEL PHYISICAL PROPERTIES TE BASEPLANE 2 AE 3 3 3 Parallel In the PARALLEL block the number of processors can be assigned to the computation with BASEMENT Depending on the computer the number of threads can be adjusted PARALLEL number threads 2 on dual core system 3 3 4 Physical properties The physical properties are global constants in a project PHYSICAL PROPERTIES gravity 9 81 m s2 viscosity 1 0e 6 m2 s rho fluid 1000 kg m3 U IV 3 3 2 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 3 5 Two dimensional simulation The BASEPLAIN_2D block within the DOMAIN block contains all information concerning the two dimensional simulation BASEPLANE 2D region name Flaz GEOMETRY HYDRAULICS Darl MORPHOLOGY E OUTPUT E 3 3 5 1 Geometry The GEOMETRY block defines the mesh
152. lly straight channel in x direction all cross sections would have the angle 0 If the orientation angle is not given it is set to this value The other essential tag is the left point global coordinates This parameter sets the global real world x y z coordinates of the outer left point of the cross section This parameter in combination with the orientation angle delivers all needed information about the spatial configuration of the cross section If U Ill 4 3 4 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE this coordinates are not given the value of distance coord is used for x and the elevation of the first point on the left for z y is set to negative distance of the first point on the left from the middle of the cross section If both parameters are set for all cross sections one can see the curved alignment of the stream in the right hand visualization see Fig 12 C D mASEMIMT PROJEKTE Coupling VilAaret topo kerrighert_neutr bme BASEMENT 1D grid file editor BEZ De Eoi BASGECHAIN GEDMETR Y X EST E 0 0 Tags Blocks Dj 2583 1 endi i mua eee m xj m x ELE Xm hp hd So ed od Sd Se kannon aoe oe h Z Q Z Fig 12 Curved alignment of the cross sections The algorithm of the cross section interpolation is briefly sketched in the following
153. ltiple cores The distribution of work load on a series of threads can be made on a small scale loop level fine grained parallelism or on a larger scale procedural or module level coarse grained parallelism See Fig 11 for illustration of these different concepts Parallelizing on each of these levels has certain advantages and disadvantages At the moment BASEMENT mainly implements a fine grained parallelism concept In principle both concepts can also be combined nested parallelism serial execution Levels of parallelism single thread parallel execution multiple threads EA EZ serial fine grained coarse grained combinated approach program parallelism a parallelism b nested pallelism c Fig 11 lillustration of different levels of parallelism Numerical applications like BASEMENT spend most of their execution time in rather small parts of the code These parts are the main calculation loops which iterate over all elements and edges of the computational grid Fine grained or loop level parallelization aims to exploit parallelism by parallelizing these time consuming loops If the serial running program arrives at such a loop its iterations are divided among a certain number of threads and are executed in parallel Afterwards a synchronization of the threads is performed so that the program can continue its serial execution see Fig 11 This parallelization approach usually requires no crucial cha
154. m can be set in OpenMP at the program start or during runtime with library calls or by setting environment variables Such parameters include for example the number of parallel threads or the choice between static or dynamic scheduling This enables the flexibility to let the user determine the number of threads used for parallelization or to optimize the parallel soeedup by varying the type of schedule VAW ETH Zurich U 5 3 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U I 5 3 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 Model Coupling 6 1 Introduction In addition to the simulation of single sub domains using BASEchain 1 D or BASEplane 2 D the software BASEMENT also provides the possibility to connect sub domains for combined numerical simulations Such coupled simulations can range from simple configurations up to simulations of river networks with integrated river junctions bifurcations or integrated 1 D 2 D modelling In Fig 14 a river network of multiple sub domains with several coupling interfaces is illustrated The coupling mechanisms thereby allow to couple hydrodynamic simulations as well as morphological simulations with sediment transport and suspended load LJ m Legend Sub domains 1D sub domain e BASEChain 2D sub domain BASEPlane y Coupling interfaces
155. material storage layer sub layer Property corresponding to three dimensional Cartesian coordinate system IR with coordinates X y z Dual property i e O bed load discharge in x direction Triple property i e bed load discharge of grain size class g in x direction A 1 1 System Manuals BASEMENT A 1 2 This page has been intentionally left blank INDEX AND GLOSSAR VAW ETH Zurich Version 4 23 2007 System Manuals BASEMENT APPENDIX AND INDEX A 2 Differential Operators d dx d dx V VAW ETH Z rich Version 4 23 2007 Differential operator for derivation with respect to variable x Differential operator for derivation of order n w r to var x Partial differential operator for derivation w r to variable x Partial differential operator for derivation of order n w to var X Nabla operator In three dimensional Cartesian coordinate system IR with coordinates x A 2 1 System Manuals BASEMENT INDEX AND GLOSSAR This page has been intentionally left blank A 2 2 VAW ETH Zurich Version 4 23 2007 System Manuals BASEMENT APPENDIX AND INDEX A 3 English Symbols Symbol Unit Definition A m Wetted cross section area a m s2 Acceleration A m7 Reduced area C m s Wave speed C Friction coefficient C Concentration C Dimensionless coefficient used for turb kin viscosity m Mean grain size of the size class g
156. mmand file for bed load transport 2 5 1 2 5 1 Define the bed material ti EE repente ed ode setas ees 2 5 1 202 ION 41541 ys 2 5 2 2 5 9 Define general parameters for sediment transport 2 5 3 2 5 4 Define specific parameters for bed load transport 2 5 4 2 5 5 Define boundary conditions for bed 2 5 4 2 5 6 Generate a geometry file 2 5 5 2 6 Perform bed load simulation Thur 3 2 6 1 2 7 Hydraulic computation using HEC RAS 3 1 3 2 7 1 VAW ETH Z rich UIV i Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 Hydrodynamics and sediment transport at the river Flaz IBHOoG uclionuuo zum Sains a A 3 1 1 3 1 1 ase Study d seripti fi u nated ncn u u e eene cote t a ea eee 3 1 1 l2 POLIOrigliSIRICIDN Gu uu 22 THU 3 1 2 3 2 ner paci eor t uuu mains 3 2 1 3 3 Setting up the command flile J J Q J J Q T J J J 3 3 1 3 3 1 FeO nm Tc n ROT 3 3 1 3 59 27 Bowers 3 3
157. mplemented Within the present implementation the determination of the control structure settings have been strongly abstracted which allow a very flexible integration of further controlling algorithms in the future As reference a classical Partial Integral Differential PID controller has been implemented By combining various control and manipulated variables within a single controller BASEMENT now offers the possibility to simulate complex series of weirs over coupled regions VAW ETH Z rich Ul 7 1 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 7 1 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 7 2 Concept of Flow Control There are many cases where the behaviour of boundary conditions such as weirs or gates depends on the actual state of the river system and cannot be described by a simple time dependent boundary setting An example would be adjusting the weir height in order to maintain a specific water level in front of the weir This process is commonly denoted as controlling The basic controller has a controlled variable such as water surface elevation which is desired to be kept at a certain level i e its target value The deviation from the current value of the controlled variable and its target value also denoted as error is then fed into the controller The controller reads the deviation and calculates the
158. mplifies the coupling setup since no restrictions are set regarding the geometries and number of cells at the boundaries or sources VAW ETH Z rich Ul 6 4 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 4 2 Exchange conditions for mixed dimensional sub domains Exchange via boundary sources Exchange Exchange equations Nr of exchange variable terms 1 gt 0 0 0 areallength weighting or conveyance weighting Water 1 D22 D surface 2 D2 1 D Bed load 2D ID 1 D22 D q 04 area length weighting 2 D gt 1 D q 2 Suspended Not available yet in 2 D load Tab 4 Exchange conditions for mixed dimensional coupling 1 index of 2 D edge or 2 D element 6 4 5 Exchange conditions for river junctions 1 D river networks Within a river network locations are encountered where river branches flow together or where a river bifurcates into several branches The flow characteristics at such conjunctions generally are multidimensional Therefore the preferable modelling approach to achieve a good accuracy is to simulate a 2 D sub domain But if such a situation shall be modelled with 1 D sub domains than special coupling concepts are required Two different approaches are implemented in BASEMENT see Fig 15 These approaches allow no more than three sub domains being part of a junction If a larger numbers of river branches are to be modelled they must be appr
159. n However at the moment the program supports any input generated by SMS 9 2 Surface Water Modelling system a commercial tool specialized on topographic grids for conservation laws which will be discussed shortly in chapter 3 5 3 4 1 Delaunay triangulation and constrained Delaunay triangulation The Delaunay triangulation is one of the most employed triangulation methods because it optimizes several quality criteria It maximizes the minimal angle and minimizes the maximum containment circle radius the maximum enclosing circle radius and the roughness of a piecewise linear interpolation It also provides good results regarding the minimization of the maximum angle but it does not find a global optimum in this case A Delaunay triangulation has the following properties It g the straight line dual of the Voronoi diagram 15 unique respects the circumcircle criterion The circumcircle criterion is respected if the circumcircle of every interior triangle does not contain other points a b C C Fig 4 a Empty circle criterion satisfied b Empty circle criterion not satisfied VAW ETH Zurich U Il 3 4 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING This corresponds to say that If ABC CDA lt 180 the empty circle criterion is satisfied respects the edge circle property for each edge exists some point free circle which passes through the end points respects the neighbour property an edge formed
160. n the sub domains by coupling interfaces using boundary conditions and source terms The following table shows the exchange variables grouped by the direction of the exchange direction of type of coupling exchange variables exchange in downstream boundary conditions Q q o C direction amp sources discharge Bed load Concer tration in upstream boundary conditions 29 direction amp sources water surface elevation Tab 3 Possible exchange conditions between sub domains In order to enable simple flexible and efficient coupled simulations some assumptions are made here e is assumed that flow directions at the coupling interfaces of the river network are known a priori and do not change during the simulation with the exception of special coupling types like the lateral coupling e The cross sections 1 D or mesh elements 2 D of the coupling interfaces should ideally be located at the same or nearby locations and have the same geometries This is necessary to reduce possible errors around the coupling interfaces due to the disregard flow taking place in between and to avoid discontinuities due to abrupt changes in the geometries e It is assumed that the flow is orthogonal over the boundaries i e the directional x and y flow components in 2 D are not exchanged separately e In 2 D coupling only summarized or averaged data are exchanged instead of exchanging data separately for each edge or element This approach si
161. new value for its manipulated variable An example for a manipulated variable would be a weir height The new value for the manipulated variable is then fed into the system i e the hydraulic simulation which finally affects the controlled variable Manipulated variable Controlled variable Deviation Monitored Error variable Controller Target value Fig 21 Basic Control Cycle In Basement the system is represented by the simulation the controller is a mathematical function f determining the values of the manipulated variables u t from the values of the monitored variables m t This can be expressed using the following mathematical expression u t f m r Logically there can be multiple monitored and manipulated variables 7 2 1 Monitored Variable A monitored variable is defined by m t t T Viarget Here v can be either a water surface elevation measured on a specific cross section 1 D or element 2 0 or a water flow over a cross section 1 0 or a STRINGDEF 2 D Verget describes the target value or in case of a feed forward controller the equilibrium state 7 is a delay time controlling when the information of the measured variable is fed into the controller 7 2 2 Manipulated Variable A manipulated variable refers to a boundary condition and can be a weir height a gate level or an outflow in case of 1 D hydrographs as downstream boundary VAW ETH Z rich
162. nges to the source code and is especially suitable for parallelizing already existing serial programs All time consuming loops can be parallelized step by step VAW ETH Z rich Ul 5 2 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT thereby incrementally increasing the parallel performance of the program Due to the small changes in the source code the robustness of a tested serial program is maintained Whereas most loops can easily be parallelized some loops contain flow dependences where the calculation results depend on an ordered succession of all iterations which is generally not maintained during parallel execution Such flow dependences can often be resolved by reorganising some parts of the loop Details on locating and removing flow dependences in loops can be found in literature e g Chandra 5 2 2 Factors influencing parallel performance Parallel performance is often measured as speedup S n which is defined as the ratio between serial execution time and parallel execution time and states how much faster the parallel application runs compared to the serial one The theoretical maximum achievable speedup is limited to the number of cores n The actual speedup is determined by several factors whose influences largely depend on size and type of the simulation Furthermore the scalability indicates wether the speedup increases linearly with increasing numbers of processors or at a slower rate The
163. ns 100 For the initial condition start from the restart file of the last calculation INITIAL Initial frieinput initial file Initial Thur txt The simulation now lasts longer 338 hours So we change it in the parameter section Beside this we increase the initial time_step to 3 PARAMETER total run time 1216800 initial time step 3 CFL 0 95 minimum water depth 0 01 maximum time step 60 The output will be plotted less often Therefore change the console and output time OUTPUT output time step 1000 console time step 1000 Run the file Thur2 bmc On my computer this takes about 23 seconds which means we calculate 50 000 real time seconds in 1 U IV 2 4 4 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS When the simulation is finished have a look at the Thur2out file take the columns of distance zbed z and eline for the time of maximal discharge 933 m s 982000 s 273 hours and plot them talweg water surface elevation 273h energy line 273h water surface elevation 0 h energy line Oh 1500 2000 distance m Fig 6 Longitudinal profile for maximum discharge VAW ETH Z rich U IV 2 4 5 Version 12 16 2010 User Manual BASEMENT TUTORIALS Then plot some interesting cross sections with their water surface elevation for the same time This can help to see what happens and which parts of the cross sections are touc
164. ns of certain constructions and buildings may be helpful The data from the country s information system can be used with some additional work for the definition of boundary conditions e g data about floor cover types The data format used for the AV93 act is called INTERLIS Data exchange mechanism for Landes InformationsSysteme VAW ETH Z rich U Il 2 1 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 2 1 3 Laser scanning Essential factors for an accurate triangulation concerning topographic raw material are accuracy of position and height as well as the density of the measured points Of special interest are therefore height model data taken by Airborne Laser Scanning LIDAR as e g provided by swisstopo This method allows for a good data base within forests Only in dense coniferous forest the determination of the terrain model tends to be impossible Of course as with all measurements from the air neither ground nor surface levels from water bodies can be obtained As the surface model generated from the LIDAR method distinguishes between terrain buildings and vegetation it provides a good starting point for further processing towards a numerical grid The federal office for topography swisstopo has commissioned Swissphoto AG to collect height data all over Switzerland for the identification of agricultural areas However this project is restricted to areas below 2000 m asl For higher located zones which
165. nt occurrence of restoration projects or the study of naturally shaped watercourses implicate the examination of larger regions also outside of the actual waterway and a more manifold shape of the channels The simple formulas for the calculation of flow behaviour used in the past showed in several cases to be insufficient to obtain the desired information The extent of the considered areas makes the application of hydraulic models in a laboratory usually employed for difficult cases impossible or too expensive So the numerical simulation of flow behaviour is in many cases the most obvious solution However existing programs have still some weak points Some are limited in their capabilities e g only steady flow no sediment transport and one dimension only or may lack in user support caused in incompleteness of documentation or training of users Furthermore inherent numerical problems request certain expertise to be overcome In addition the preparation of the input data and the processing of the results to a shape which facilitates the interpretation are often very laborious The aim of the software system BASEMENT in terms of its free availability and its accompanying scholar programs is to enable a broader range of people to skilfully process river modelling projects in a justifiable amount of time VAW ETH Zurich Ul 1 1 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally lef
166. o produce animated graphics in time Like this the results can be visualized Most of the results in manual RIII Test Cases were produced using SMS 10 U II 3 5 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING Szenarien Animation Fig 9 Simulation procedure with use of SMS VAW ETH Zurich U Il 3 5 3 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING This page has been intentionally left blank U II 3 5 4 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING References Bath T J 1994 Aspects of unstructured grids and finite volume solvers for the Euler and Navier Stokes quations VKI Lecture Series 1994 05 Bern M and Eppstein D 1995 Mesh generation and optimal triangulation Computing in Euclidean Geometry D Z Du and Hwang editors 2 Edition pp 47 123 World Scientific Singapore 1995 Bern M and Plassman P 2000 Mesh Generation Handbook of Computational Geometry J Sack and J Urrutia editors Elsevier Science 2000 VAW ETH Zurich U Il References Version 10 22 2009 User Manual BASEMENT PRE PROCESSING This page has been intentionally left blank U 1 References VAW ETH Zurich Version 10 2 2009 2 GRAPHICAL USER INTERFACE of BASEMENT System Manuals BASEMENT This page has been intentionally left blank VAW ETH Zurich User Manual BASEMENT GRAPHICAL USER INTERFACE Table
167. on 2x2m grid interpolated from DSM AV raw Tab 2 Products offered by swisstopo MM ANE S l 10x10m 20x20m Photogrammetric interpretation ASCII xyz height accuracy 3 5 m 50 50 of aerial photos from 1995 96 or GRID midland 7 10 mountains DEM LIDAR 31000 250x 160 Lidar Airborne Laser Scanning ASCII xyz Height accuracy 30 cm on m spacing ASCII commission 1 1 3m Arclnfo Tab 3 Products offered by Swissphoto AG U Il 2 1 4 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 2 2 River related data sources The following list provides some more Swiss data sources for real world problem modelling and boundary conditions River cross sections Primary use for 1d models also qualified for 2d models to improve topography data within a rivers area Terrestrial mapping optimal quality and format according to the cross section database of the Federal Office for Environment FOEN formerly FOWG bafu admin ch Terrain topography Basic dataset for simulations with spatial 2 or 3d models Optimal quality and format ASCII x y z as swisstopo DIM AV DOM AV New swisswide high resolution DIM DOM based on laser scanning http www swisstopo ch de digital dom htm Surface texture and special buildings Declaration of roughness coefficients porosity and erosion resistance of surfaces Optimal format INTERLIS 1 as e g DOM AV or floor cover plans AV93 generated by
168. on 12 16 2010 User Manual BASEMENT TUTORIALS 2 3 Setting up the command file 2 3 1 Project The first command file is called Thur1 bmc The first step is to define a project by its name the author and the date PROJECT title Thur author rm date 10 8 2006 2 3 2 Domain Then a domain is defined in which all parameters concerning this computation are defined The first parameter is the name of the computation region DOMAIN multiregion Thur acd 2 3 3 Define the physical properties The Physical properties normally do not change from one project to another PHYSICAL PROPERTIES gravity 9 83 viscosity 0 000001004 rho fluid 1000 2 39 4 dimensional simulation The next step is to declare a BASECHAIN_1D block This will make the program execute a 1 D simulation The name of the computational region is given here BASECHAIN 1D region name Thur Altikon VAW ETH Zurich U IV 2 3 1 Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 3 4 1 X Define the geometry The next block defines in which file the topography is stored and which type of geometry file is used The cross section names are listed from upstream to downstream GEOMETRY type basement file ThurTopo bmg Cross Section Order e 62 093 MOS 56 66551 2 3 4 2 Define hydraulic information All information concerning the hydraulic simulation is declared in the block HYDRAULICS HYDRA
169. opagation 5 1 2 Parallel computer architectures Types of parallel computing can be differentiated in many aspects concerning hardware software concepts and various other criteria Frequently parallel computers are classified in two groups which differ in the way memory is organized between the multiple processors In so called distributed memory architectures each core possesses its own memory unit which can not be accessed by any of the other cores Distributed memory systems usually consist of large computer clusters which are connected via a network right side of Fig 0 Such a parallelization concept enables the use of very large numbers of processors and is employed in high performance computing HPC But software programming maintenance and debugging for distributed memory systems generally is very time consuming and costly Complex message passing interfaces via network are necessary for data exchange and synchronizations between the processors Out of these reasons distributed memory VAW ETH Zurich Ul 5 1 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT systems or combinations of distributed and shared memory systems so called hybrid systems are not further discussed here Shared Memory Architecture Distributed Memory Architecture Fig 10 Shared memory architectures left and distributed memory architectures right with four cores On the other hand shared memory architectures h
170. or such cases is not trivial and unclear But such situations may arise in coupled large scale simulations where grain classes get finer along course of the river A flexible approach is adopted here which allows the usage of differing compositions as well as different numbers of grain classes of the sub domains For data exchange the bed loads of each grain class are mapped on the grain classes of the receiving sub domain The mapping is achieved by three successive steps as illustrated in Fig 17 The sediment mass balance is thereby fulfilled VAW ETH Z rich Ul 6 4 5 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Determine grain class borders lt I right 91 right g2 right g3 left 02 left g3 Input grain classes Split grain classes d m Target grain classes gt Modified input grain classes gt sediment Target grain classes gt d m Fig 17 Mapping of grain compositions from one sub domain to another U I 6 4 6 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 5 Synchronization Concept 6 5 1 General remarks on synchronization For the coupling of sub domains a synchronization mechanism must be implemented which directs the execution of the sub domains and controls the data exchanges at the appropriate times The type and complexity of the synchronization effort thereby generally depends on the degr
171. ordinates X y z Molecular viscosity Kinematic viscosity ul p Isotropic eddy viscosity Turbulent kinematic viscosity v V cu h Base kinematics eddy viscosity Mass density fluid Bed material density Cartesian components of bottom shear stress vector Vector of shear stress at bottom due to water flow Critical shear stress related to grain size Cartesian components of surface shear stress vector Vector of shear stress at water surface e g due to wind Area of an element Hiding factor A 4 1 System Manuals BASEMENT INDEX AND GLOSSAR This page has been intentionally left blank A 4 2 VAW ETH Zurich Version 4 23 2007
172. ormation systems several norms for a standardized data representation exist Examples are the OpenGIS Geography Markup Language GML or the norms used in owitzerland INTERLIS SN 612 030 612 031 and GEOBAU SN 612 020 VAW ETH Z rich U Il 2 5 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING This page has been intentionally left blank U II 2 5 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 Grid generation 3 1 Introduction The numerical methods used for the approximation of differential equations needed in flow simulations are based on a discretization of the domain in simple small shapes The complex of these elements forms a mesh In BASEMENT the finite volume method being particularly valuable for fluid dynamics is used To describe a topographic surface the terrain data is often triangulated to allow a perspective representation of the topography The result is a piece wise linear interpolation of the surface This triangulation can be used directly as mesh for simulations as it permits to have the original data in the vertices of the initial grid and no interpolation is necessary However most of the time the mesh has to be transformed somehow Regions of high interest need some mesh refinement for higher accuracy and areas of lower interest are often coarsened to save computing power vertex triangel Fig 2 Unstructured grid Triangulation In numerical simul
173. oximated by multiple junctions placed in small distances Ul 6 4 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT inflow 14 a V b Fig 15 Modeling of a river junction with two different approaches black arrows indicate a confluence of river branches red arrows a bifurcation control volume Following the first approach a junction can be regarded as region where three different river branches meet and mutually exchange data a A control volume is defined to which mass and momentum conservation principles can be applied A simple approach is here balancing discharges and assuming equal water surface elevations along the junction PB a Exchange conditions Nr of equations Bed Load 25 Oi tees Suspension nus En oC u2 s m downs Tab 5 Exchange conditions for river junctions The second approach is to regard the junction as a lateral inflow of a tributary into a river at a specified location b The discharge and sediment is passed from the tributary to the river as lateral inflow via source term Additionally the water level at the inflow cross section can be passed in return to the tributary Despite its simplicity this approach can be suited well to simulate simple river junctions in 1 D 6 4 4 Exchange conditions for river bifurcations 1 D river networks In case of modeling a river branch which bifurcates into two branche
174. performance If multiple nodes lie on a straight line within the cross section there is redundant information present which can be removed without reducing the accuracy of the computations Therefore identifying and removing these redundant nodes is a frequent and recommended task before running the simulations BASEMENT offers a tool which performs this task automatically without need for costly manual operations To access this tool open the Tools menu and click on the Remove nodes option The following dialog opens J Matc hing tolerance Max deviation From line Far node to be removed h nsn Fig 9 Node removal dialog for setting up the tolerance In this dialog you can define the maximum tolerance by which a node may deviate from the straight line of its two neighbours If the node lies within this tolerance the node removal is applied If you set the tolerance to small values only nodes are removed which are almost exactly situated on the line If you increase the tolerance more nodes will be removed but some more information about the cross section profile may get lost Usually one should try different tolerances until the best compromise between computational performance and accuracy is found Also the algorithm can be applied multiple times U Ill 4 3 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE The applied algorithm loops all nodes of the cross sections and checks if a node is s
175. ping can be used as described in the previous chapter Thereby BASEMENT finally determines the time steps for all sub domains including the external sub domain in a way that all time steps are multiples of a minimum base time step Using two way coupling is sensitive to dead locks and may need some experimenting Note Please be aware that the external coupling approach is still in an experimental stage Also the usage of this coupling requires programming efforts and knowledge in TCP IP programming and XML parsing External coupling may require the implementation of special boundary conditions in the BASEMENT model For example coupling with a groundwater model requires leakage boundaries for water exchange to be set If you want to make use of such a coupling type you may contact the developer team regarding the implementation of appropriate boundary conditions in the model VAW ETH Z rich Ul 6 6 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 6 6 2 Data exchange over TCP IP The data exchange between BASEMENT and the external program takes place using TCP IP communication This has the advantages that it is generally faster than communications via files and enables the coupling between different computers via intra or internet even using different operating systems Create connection The communication requires an IP address and a port number as identifier and takes place using TCP sockets Usually BASEMENT run
176. priate models for bed load as well as suspended load are forming the core of the software system Two of the main project tasks were the renewal and further development of the existing 1 D 2 D models Floris 2dMB The one dimensional model complies with the upper bound of the considered spatial scale maximum idealization and slightest resolution of spatial processes and is meant to provide appropriate boundary conditions for the 2 D and 3 D models The main focus of conception and development was the stability of the numerical models the flexibility of the computational grid and the combination and efficiency of the method of calculation problem dependent equations coupling of models parallelization The development process was orientated at the concepts of object orientation to assure transparency documentation and flexibility of the software system as far as possible Future developments applications related to practice and scientific projects shall build upon the environment of BASEMENT to ensure sustainability VAW ETH Zurich Ul 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank Ul 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 1 General Use 1 1 Problem Description In connection with watercourses and river areas increasingly complex problems have to be addressed The estimation of floods the more freque
177. quence only discharges are exchanged between the sub Ul 6 4 4 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT domains The exchange between the sub domains is calculated as weir flow over the dykes of the 1 D cross section or as weir flow over the edges of 2 D sub domain The weir level is chosen as the higher elevation of the dyke or the corresponding edge As weir width b the weir formula the length of the 2 D boundary edge is taken Exchange of discharge is possible in both directions either from the river into the floodplains or backwards depending on the water elevations in the 1 D cross section and the corresponding 2 D element To enable a flexible coupling approach it is possible to connect a 1 D cross section with multiple 2 D elements The coupling interfaces are defined using a list from which the connections are automatically extracted and generated during a pre processing step Ooo Exchange conditions Nr of equations Discharge 2 1 D gt 2 D Q J2gh If 25 ip 2252 side weir side weir reduction factor 3 2 D gt 1 D O Woy J22h if 2515 lt 252 weir overfall over edge Tab 7 Exchange conditions for lateral coupling 6 4 6 Data exchange for morphological simulations with multiple grain classes In morphological coupled simulations the possibility exists that sub domains can have differing grain compositions The handling of data exchange f
178. r part of the window the Input is validated and possible parse errors are indicated For the sake of completeness it is mentioned here that the command file can still be built up and edited with a simple text editor CS BASEMENT v2 PROJECT title 2D_Tutorial author Lv date 23 03 2010 DOMAIN 1 multiregion Flaz PARALLEL 1 number threads 2 PHYSICAL PROPERTIES 1 gravity 9 81 viscosity 0 000001 rho_fluid 1000 BASEPLANE_2D region_name Flaz GEOMETRY type sms file Flaz_mesh 2dm STRINGDEF name Inflow node ids2 123456789 STRINGDEF name Outflow node ids 9478 9479 9499 9500 9501 9519 9533 9546 9552 HYDRAULICS BOUNDARY type hydrograph string_name Inflow file Inflow_stationary txt slope 10 0 BOUNDARY type harelation string_name Outflow slope 2 0 INITIAL type dry FRICTION type strickler default Friction 30 input type index table index 1 2345678 9101112 1 No errors or warnings Press Validate to check again Fig 4 Command File Editor Raw Edit Window VAW ETH Zurich Version 12 16 2010 Validate Apply U III 3 3 1 User Manual BASEMENT GRAPHICAL USER INTERFACE This page has been intentionally left blank U III 3 3 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 4 Edit 1 D Grid 4 4 The BASEMENT 1 D Grid File Editor When t
179. re being used VAW ETH Z rich U 4 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U I 4 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 4 1 Flow of main activities Build and Name Project Preparative Work Scenario definition Topography computational mesh Import rough topographic data Import cross sections Add break lines manually Build terrain model triangulate Build cross sections from terrain model Determine mean riverbed level Generate computational mesh Define properties of mesh elements Roughness Grain sizes distribution mean diameters Flow through no flow through elements Mobile fixed bed elements Transport relevant not relevant elements Shear stress Define approaches Simulation Matrix Sediment transport formulas Roughness Friction formulas Debris flow type and approach Define initial boundary conditions and required results Boundary conditions Time discharge from Inlet Hydrographs Water level time series at outflow Special hydraulic elements weir step bridge block wall Sediment discharge dependent on Hydrographs Concentration of suspended material Grain size distribution Height of Subsurface Viscosity Initial conditions Waterlevel Sediment bed level Slope Flow velocities Grain size distribution Required results Monitoring point or se
180. red in the topography file FRICTION type strickler default friction 35 VAW ETH Zurich U IV 2 3 3 Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 3 4 3 3 Declare parameters for hydraulic computation For the first computation the simulation time is set to 15000 s For a computation on a dry bed a small initial time step should be chosen It is used only at the very beginning as there is no flow in the channel from which the time step could be deduced The maximum time step should be bigger as all time steps computed during the simulation PARAMETER total run time 15000 initial time step 1 maximum time step 60 CFL 0 95 minimum water depth 0 0001 Define the hydrograph file named ThurSteadyHydrograph txt Ve Q 0 30 100000 30 2 3 4 4 Define output If only standard output is needed only the time step for file printing and for console printing has to be defined If Tecplot software is available it is also very useful to generate a tecplot file OUTPUT output time step 100 console time step 100 SPECIAL OUTPUT type tecplot all output time step 100 U IV 2 3 4 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 4 Perform hydraulic simulations 2 4 1 Perform steady flow simulation Thur1 The first simulation has the aim to create a steady flow as initial condition Place the 3 files in the same folder and start the simulation by double clicking on the command
181. rmations the user still has to retain an overview over the required steps leading to the final computational mesh importrow perform terrain e topografic data information manually triangulation model define wanted manipulate evaluate terrain mesh qualities gt terrain model q model 4 generate b addpropertiesto mesh elements y 7 computational mesh computation al mesh Fig 6 Activity diagram generate computational mesh The following activity diagrams show a possible procedure for different project scenarios VAW ETH Z rich Ul 4 2 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 4 2 1 Sediment balance in a river 1 D importorenter cross sections define number of N Streamtubes as Ec ms lt OnTIAI c c EN define foreland defineflown define bed load defineK foreach setsediment layer data gt main chanel throughzones activezones section sector _ foreach section sector Suc 2 di E define Y branches boundary conditions at branch connections and ends p enter or calculate initial conditions d perform N Simulation CN represent
182. s the upstream discharge and sediment must be distributed among the two downstream sub domains The distribution factor among the downstream sub domains has to be chosen according the local conditions The downstream water elevations of the two downstream sub domains are averaged and then passed in upstream direction VAW ETH Z rich Ul 6 4 3 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT Exchange conditions Nr of equations nl b g T 1 7 P O usa C m T 1 Q town2 nie Tab 6 Exchange conditions for river bifurcations 6 4 5 Exchange conditions for combined 1 D and 2 D modelling The combined 1 D river flow and 2 D floodplain modelling bases mainly on the approach presented by Beffa 2002 A conceptual overview is given in Fig 16 which illustrates river cross sections of the BASEchain sub domain and the 2 D mesh of a floodplain modelled with a BASEplane sub domain combined1D channel and 2D floodplain modelling 10 cross 2D floodplain section 1D cross nlai gt 4 2D floodplain section P coupling interface Cross section BASEchain BASEplane Fig 16 Conceptual overview of combined 1 river flow 2 D floodplain modeling The coupling interfaces between the sub domains are implemented as one way couplings via source terms As a conse
183. s as the server application and must be started first Then it waits for an incoming connection request After the incoming request a connection is established with the external program and the connection information is sent to the external program socket descriptor In case of multiple external programs BASEMENT waits until all connections are established before it starts the computations client execute request connect socket 1X3 Fig 19 Connection request from external program client to BASEMENT server Data packet The data is wrapped in data packets using the common XML format whereby the data values and several additional attributes must be specified All communications between the programs take place by sending data packets Therefore also additional information like e g the time or the time step size must be included in the data packet It is also possible to send or receive multiple data packets for different data types or boundaries The XML tag has the following structure Data attribute 1 7 attribute2 gt lt Data gt The data values within the XML tag can either be written as ascii or binary data If ascii format is used a semicolon separates multiple data values from each other e g Data 10 0 10 0 10 0 Data Ul 6 6 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT The following attributes can be set
184. s granted herein No fees may be charged for use reproduction modification or distribution of this Software neither in unmodified nor incorporated forms with the exception of a fee for the physical act of transferring a copy or for an additional warranty protection 4 Obligations of licensee a Copyright Notice Software as well as interactively generated output must conspicuously and appropriately quote the following copyright notices Copyright by ETH Zurich VAW Faeh R Mueller R Rousselot P Vetsch D Volz C Vonwiller L Veprek R Farshi D 2006 2011 VAW ETH Zurich Version 7 8 2011 System Manuals of BASEMENT LICENSE AGREEMENT 5 Intellectual property and other rights The licensee obtains all rights granted in this Agreement and retains all rights to results from the use of the Software Ownership intellectual property rights and all other rights in and to the Software shall remain with ETH Zurich licensor 6 Installation maintenance support upgrades or new releases a Installation The licensee may download the Software from the web page http www basement ethz ch or access it from the distributed CD b Maintenance support upgrades or new releases ETH Zurich doesn t have any obligation of maintenance support upgrades or new releases and disclaims all costs associated with service repair or correction 7 Warranty ETH Zurich does not make any warranty concerning the warranty of merchantab
185. s in general of cells control volumes In the software model the mesh is based on three different objects node the nodes mass free points in relation to a coordinate system edge the edges which are defined by two nodes and define the place of information flux between two elements in Finite Volume Methods element the elements which are defined by several nodes and define the place of the physical variables e g cell centered methods This data structure allows for similar treatment of 1 D and 2 D methods and schemes As the difficulty of mesh generation occurs in many different computational tasks a broad range of different triangulation techniques or mesh refinement methods can be found in the literature Some of them are specially designed for a certain discretization scheme but can also be used elsewhere As there is nothing such as an ideal or perfect mesh the user is recommended to produce different grids and compare their behaviour to find the best solution There are commercial tools available which can be used for the grid generation e g SMS However the BASEMENT standard for grid representation See Reference manual also allows for self created meshes U 3 2 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 3 2 2 BASEchain one dimensional model Discrete Representation 1d Overview CrossSection original partition basic geometrical information
186. s well as object oriented programming On the project level the framework slightly changed The initial scope within BASEMENT was developed the Rhone Thur project has been finalized by the end of 2007 The sequel is called Integrales Flussgebietsmanagement It has the same co financer as its predecessor namely the Swiss federal office for the environment FOEN and basically the same participating institutions EAWAG WSL LCH EPFL and VAW ETHZ The funding runs until the end of 2011 Due to the retirement of Prof Dr Ing H E Minor in summer 2008 our laboratory is solely represented in the project committee by Dr R F h at the moment he emphases of the new proposal for the further development of BASEMENT are advanced topics of hydraulics and sediment transport such as secondary currents and lateral erosion Furthermore the efficiency of the software should be increased by the implementation of appropriate parallelisation and coupling approaches Since the last minor release a long time passed which was mainly consumed by a general revision of the software After five years of development a diligent consolidation was expedient In addition the coincidence of a new team member offered an unbiased reflection of the source code All in all it was very worthwhile Last but not least there are numerous bugs fixed and some new features in the current version Mainly the efficiency of the software has been improved The first stage o
187. scope of the license a Use The licensee may use the Software according to the intended purpose of the Software as defined in provision 1 by the licensee and his employees for commercial and non commercial purposes The generation of essential temporary backups is allowed b Reproduction Modification Neither reproduction other than plain backup copies nor modification is permitted with the following exceptions Decoding according to article 21 URG Bundesgesetz Uber das Urheberrecht SR 231 1 If the licensee intends to access the program with other interoperative programs according to article 21 URG he is to contact licensor explaining his requirement If the licensor neither provides according support for the interoperative programs nor makes the necessary source code available within 30 days licensee is entitled after reminding the licensor once to obtain the information for the above mentioned intentions by source code generation through decompilation c Adaptation On his own risk the licensee has the right to parameterize the Software or to access the Software with interoperable programs within the aforementioned scope of the licence d Distribution of Software to sub licensees Licensee may transfer this Software in its original form to sub licensees Sub licensees have to agree to all terms and conditions of this Agreement It is prohibited to impose any further restrictions on the sub licensees exercise of the right
188. se of tables for the computation of the water surface elevation and other hydraulic variables is chosen for this example In the case of tables all properties are pre computed for a given set of points and only updated in case of a non negligible change of the soil This is accomplished using the block SECTION COMPUTATION in PARAMETER As all variables are calculated for several water surface elevations the maximum and minimum intervals between the different levels have to be set accordingly The default spacing is given by max_interval min_interval Whenever the bed changes the table is updated accordingly 3 D Thur3_1D Thur3 bmc BASEMENT command file editor oles File Tools Input Structure gt SECTION COMPUTATION PROJECT New Tags Blacks Er DOMAIN PHYSICAL PROPERTIES Add Tag 2 available Nri BASECHAIM 1D Thur Altikon HE GEOMETRY I HYDRAULICS type BOUNDARY hydrograph BOUNDARY hqrelation table eal IMITIAL S PARAMETER ni nn 2 MORPHOLOGY 2 PARAMETER BEDMATER LAL max interval GRAIM CLASS MIXTURE unique 0 2025 SOIL DEF Fixed 3 SOIL DEF mobile IASC Fig 4 Definition of table values VAW ETH Z rich WAIN 2 255 Version 12 16 2010 User Manual BASEMENT TUTORIALS 2 2 5 Characterisation of the sediments Two types of ground will be defined 1 the ground is not erodible 2 the ground is composed by sediments with a mean diameter of
189. ser Manual BASEMENT GRAPHICAL USER INTERFACE This page has been intentionally left blank U Ill 3 1 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 3 2 Create New or Edit Existing Command File A new Command File is created form the menu bar in the Command File Editor Choose File on the menu bar and select New The whole command file consisting of Blocks and Tags can be built up from scratch For further details on how to add Blocks and define Tags see chapter 2 2 2 in this manual If you want to open an existing command file you can do this from the Command File Editor or directly from the BASEMENT Main Window From the Command File Editor choose File on the menu bar and then select Open Then you browse and choose your file as usually Don t forget to save your changes made in the command file before you run a simulation VAW ETH Z rich U III 3 2 1 Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE This page has been intentionally left blank U Ill 3 2 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT GRAPHICAL USER INTERFACE 3 3 Tools 3 3 1 Edit Raw Another way to edit a command file is to edit basically the command file in a raw text mode For this purpose choose Tools on the menu bar and select Edit Raw The Editor window will pop up as shown in Fig 4 Long standing users of BASEMENT will recognize the input structure of the former command file In the lowe
190. software technical features like parallelization or the coupling of sub domains advanced features for sediment transport and flow control are making it a reliable tool for professional as well as scientific applications With the new GUI another hurdle has been cleared and a new era of the software in terms of usability has begun We are looking forward to the further development as well as upcoming releases of BASEMENT and we are curious about how the software will establish itself in the future Z to Prof Dr R Boes Committee Member of Project Integrales Flussgebietsmanagement Director of VAW May 2010 VAW ETH Z rich Version 6 3 2010 System Manuals of BASEMENT LICENSE AGREEMENT SOFTWARE LICENSE between ETH Zurich Ramistrasse 101 8092 Zurich Represented by Prof Dr Robert Boes VAW Licensor and Licensee 1 Definition of Software The Software system BASEMENT is composed of the executable binary file BASEMENT and its documentation files System Manuals together herein after referred to as Software Not included is the source code Its purpose is the simulation of water flow sediment and pollutant transport and according interaction in consideration of movable boundaries and morphological changes 2 License of ETH Zurich ETH Zurich hereby grants a single non exclusive world wide royalty free license to use Software to the licensee subject to all the terms and conditions of this Agreement 3 The
191. t blank Ul 1 1 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 1 2 Product Delineation and Employment Domains 1 2 1 Product Delineation BASEMENT is a river engineering tool which supports the engineer in the solution of tasks in the domain of river area modelling The program permits reliable computations based on state of the art numerical tools constant onward development and successive realisation of case studies Unlike currently used programs for the simulation of a specific flow behaviour BASEMENT intends the arrangement of many different problem types with one single tool to gain a integrated understanding for the initial position the solution process and its results 1 2 2 Employment Domains The aim of BASEMENT is to permit the solution of as many problems as possible in the domain of river engineering especially in cases for which the traditional dimensioning tools are insufficient and studies including physical hydraulic models are not possible or too expensive Typical employment domains are Several problems in relation with the sediment transport of water courses for instance the future development of deltas and alluvial fans the long term evolution of the bottom of channels or the aggradations of storage spaces and the consequences of their scavenging River engineering enterprises which imply the modification of the channel geometry as this can be the case for example
192. ta sources data sources for topography and also hydrology and sediment Most data sources in the next few sections are somehow related to Switzerland Other regions and countries provide similar data depending on the actual law 2 1 1 Terrestrial data or surveying with differential GPS ourveying or special engineering agencies provide terrestrial terrain data or terrain data obtained by differential GPS DGPS of the desired quality A pure terrestrial recording is more expensive because at least two workers are needed in contrast to a DPGS scan which can be done by one employee only The survey with GPS needs a certain visibility concerning the GPS satellites The accuracy depends on the exactness of positioning for the reference point but usually lies in the range of a few centimetres The terrain data is delivered in different formats as e g xyz coordinates or GEOBAU standard Be sure to specify your claims on quality of the data as resolution typical terrain deformations but also the desired data format when asking for a tender offer 2 1 2 Official topographic survey According to a decision of the Swiss federal assembly Einf hrung der amtlichen Vermessung AV93 the bureau of land charge register provides digital cadastral data almost over the whole country ca 8096 and data from the country s information system ca 30 The cadastral information is just of secondary use as the parcels are all flat However the ground pla
193. to be constant with a thickness of 0 1 m PARAMETER porosity 40 density 2650 kg m3 control volume type constant control volume thickness 0 1 m 3 5 1 2 Bed material In the BEDMATERIAL block the grain classes the composition the thickness of the soil layers the level of the fixed bed and the assignment of the soil to the mesh is defined in several sub blocks BEDMATERIAL GRAIN CLASS oe MIXTURE ieri SOIL DEF JUNE FIXED BED TE SOIL ASSIGNMENT 3 5 1 3 Grain size distribution The single grain simulation is performed with only one grain class of a given diameter e g the mean grain diameter GRAIN CLASS diameters 50 mm U IV 3 5 2 VAW ETH Z rich Version 12 16 2010 User Manual BASEMENT TUTORIALS 3 5 1 4 Grain mixture Since we have only one grain size the volume fraction is equal to 100 MIXTURE name single grain volume Traction 100 3 5 1 5 Define the soil composition The soil layers and the according sediment mixture are defined in the SOIL DEF block For a single grain simulation it is not important how many layers are defined The negative bottom elevation defines the thickness of the layer Below the last layer a fixed bed is assumed If no LAYER block is defined then automatically a fixed bed on the surface is assumed We use this especially for the river bed near the upper boundary condition to avoid
194. tually are BASEchain The one dimensional numerical tool named BASEchain enables the simulation of river reaches based on cross sections with respect to sediment transport A coupling with the 2 D tool is foreseen BASEplane The two dimensional numerical tool named BASEplane enables the simulation of river reaches as well as flood plains bases on a digital terrain model with respect to sediment transport BASEspace planned The three dimensional numerical tool named BASEspace is meant for the simulation of local flow fields based on spatial geometry with respect to sediment transport A coupling with the 2 D tool is foreseen For a list of implemented features of each model please refer to the actual release notes VAW ETH Zurich Ul 2 1 1 Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT This page has been intentionally left blank U 1 2 1 2 VAW ETH Z rich Version 7 8 2011 User Manual BASEMENT BASIC SIMULATION ENVIRONMENT 3 Components To reveal the black box of the numerical models Fig 2 gives a graphical insight The simulation tools of BASEMENT can be subdivided into three different parts mathematical physical modules consisting of the governing flow equations computational grid representing the discrete form of the topography the numerical modules with their methods for solving the equations In the next few chapters an overview of these modu
195. upper BOUNDARY block changes to BOUNDARY type hydrograph string name Inflow file Inflow instationary txt slope 10 0 per mill discharge m3 S 0 10000 20000 30000 40000 50000 60000 70000 80000 time s Fig 21 Hydrograph of the flood event of July 2004 VAW ETH Z rich U IV 3 4 3 Version 12 16 2010 User Manual BASEMENT TUTORIALS a lnflow_instationary txt Notepad _ Oleg File Edit Format View Help Inflow highwater 2004 ff time s Q ms s D 0 50 0 2000 30 2 2300 30 7 250 30 8 29000 122 29300 1242 29600 124 29900 124 30200 l27 30500 4 4 4 6 4 6 1 6 3 4 1 sL 9 Fig 22 Inflow hydrograph stored in the file Inflow_instationary txt Note that the points are just illustrative in order to show the first and last line of the file In the PARAMETER block the total run time of the simulation is increased up to 80 000 seconds in order to capture the whole flood event total run time 80000 Last but not least the OUPUT block has to be adjusted to the needs of the simulation For the unsteady simulation maxima values may be of interest U IV 3 4 4 VAW ETH Zurich Version 12 16 2010 User Manual BASEMENT TUTORIALS OUTPUT output time step 2000 console time step 100 SPECIAL OUTPUT format sms type node centered values dept
196. ur lines PSLG planar straight line graph e g a DEM with addition of break lines This is the most general case which the input is a set of vertices and non crossing line segments that must be conserved the triangulation Although the raw input data e g from a point cloud could be directly used as a grid usually further transformations are performed to gain a suitable computational mesh A suitable mesh is mainly defined by its quality VAW ETH Z rich U Il 3 2 1 Version 10 22 2009 User Manual BASEMENT PRE PROCESSING This page has been intentionally left blank U Il 3 2 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 3 3 Mesh quality 3 3 1 Shape of mesh elements The shape of the elements of the meshes has an important effect on the applicability of numerical methods Speed due to convergence time accuracy and stability of a simulation depend strongly on the quality of the employed mesh Therefore it is important to produce the best possible triangulation for the application oize shape and number of the elements play an important role for the quality of the mesh Possible characterizations of a triangulation which can be optimized depending on the application are minimal angle maximal angle maximum edge length total edge length maximum height area of the triangle aspect ratio ratio of the length of the longest side to the height definition after
197. ving obtained his master s degree at ETH Zurich Within the scope of his master thesis at the VAW he studied the hydrodynamics and ecological impact of floods at the river Flaz using BASEMENT Some of his experiences with the application of BASEMENT and selected results are documented in the new tutorial on 2 D simulations in the user manual UIV His current duties are the application and testing of the software in terms of project work We were also very lucky being able to engage Dr Ratko Veprek as a distinguished software engineer for a limited period of time His contributions to the software such as flow control of river systems computational efficiency and the graphical user interface just to name a few are of great value Unfortunately he will leave us by the day of the release to take on a post doctoral position abroad According to the announcement in the preface to version 1 4 the second major version of BASEMENT is released with little delay but with all the more important improvements and substantial new features First of all the new version 2 0 of the program comes with a graphical user interface GUI which allows running or stopping simulations and tracking the progress Furthermore the model setup and configuration i e the assembling of the command file is completely integrated into the GUI The user is guided through the setup and any input is validated directly In addition the integrated help function which is based on t
198. which means that data is exchanged explicitly between the sub domains at certain time intervals This approach is simpler to implement than an implicit approach especially regarding the coupling of sub domains with mixed dimensionalities However in comparison to an implicit coupling approach special care must be taken to achieve robust and stable combined simulations 6 3 1 One way coupling and two way coupling A simple way to couple two sub domains is to exchange data only in one direction from upstream to downstream Such a situation is termed as 1 way coupling from here on It has the advantage that the upstream sub domain can run independently from the downstream sub domain and the flow variables are passed over at some time intervals to the downstream sub domain But being a one directional coupling no information from downstream can travel upstream Therefore this type of coupling is restricted to cases where no backwater effects from downstream take place or such influences can be neglected In contrast a two way coupling enables mutual interactions between the sub domains by providing mutual data exchange In two way coupled sub domains backwater effects from downstream can influence the upstream sub domain Instead of executing the sub domains sequentially from upstream to downstream direction here the sub domains are executed simultaneously The two way coupling approach has the difficulty that no unique flow variables are present
199. y its medium diameter and has a percentage The choice of the numbers of grain classes and thus the resolution of the material composition depends on the size of the problem and the computing power available The classification of the grain diameters which represent a grain class strongly affects the transport behaviour of the whole material and the efficiency of the transport model It is recommended to run several simulations with one but also with more grain classes and to compare them U II 2 4 2 VAW ETH Z rich Version 10 22 2009 User Manual BASEMENT PRE PROCESSING 25 GIS Interface A geographic information system GIS as assistance for a numerical simulation model shall provide several data in best possible spatial and temporal resolution but not necessarily in a model inherent format The data structures described in the following are just proposals For all of them one has to decide a priori whether the raw data shall be saved per se or in a processed form raw data and pre GlS processed data 2 5 1 Administration of geographical data Generally one distinguishes two kind of data types matrix data based on a uniform matrix e g air taken pictures and vector data e g property borderlines Vector data serves for the visualization of the geometry and uses different data structures Objects with simple geometry see OpenGIS Simple Feature Specifications are e g points lines and polygons For complex geometries see Open
200. y limited affordable and manageable by large research institutions today nearly all new available computers provide capacities for parallel computing The famous law of Moore which predicts an increase in computer power about a factor 2 every two years is expected to be valid also in the near future due to parallel computing Manferdelli 2008 In parallel computing the increase of execution speed is mainly achieved by sharing the overall work load between several processors instead of further accelerating single processors by an increase of tact rates Theses changes in computer hardware architectures raise the needs for new parallel programming concepts Programs originally developed and optimized for execution on a single processor can not automatically benefit from the availability of multiple processors Specific software techniques and algorithms must be developed and applied to exploit the additional performance provided by parallel hardware The software BASEMENT therefore needed to be adapted and optimized for the use of parallel computers Some typical hydrodynamic simulation scenarios with high demands on performance are e multidimensional flow simulations with large computational domains consisting of a very large number of elements as well as simulations of large river networks e simulations of river flow over long time periods especially with regard to morphological changes and e real time simulations of river flow and flood wave pr
201. ystems 7 1 Introduction The flow characteristics of a river system are not only governed by the character of a channel the morphology and topography but also by regulations for hydropower stations and lakes Such regulations commonly demand that a certain water level is maintained or impose certain limits on the maximum discharge The exertion of control structures has commonly a significant direct impact on certain river sections or even on the whole river system The setting of the control structures over time cannot be defined in advance but depends on the reaction to a change of the whole river system The numerical simulation of regulations is very helpful to properly judge such river systems as it allows assessing and optimizing the effect of individual regulations of control structures on the whole system This is of great importance as efficient flood control demands an optimal use of existing retention structures Therefore the automatic steering of control structures has been added to BASEMENT covering 1 D and 2 D simulations as well The chosen approach allows the simultaneous combination of different controlled and manipulated variables Controlled variables can be either water surface elevations or discharges Here not only fixed values can be defined but also series in time or values depending on the current flow in the river system As manipulated variable settings of weir or gates and an abstract outflow hydrograph has been i

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