A Tutorial for Preparing GEOtop Input Files with JGrass
Contents
1. Figure 3 4 h pitfiller Dialog box where the names of the input and output maps are specified 763 9551 006 047 1048 1389 1190 2307 1332 3226 1474 4746 1616 5063 1758 5983 1900 6002 2042 7821 2184 874 Figure 3 5 h pitfiller Depitted elevation map The Flanginec Basin 15 3 Data Preprocessing for the Extraction of the Hydrographic Basin 3 2 FlowDirections The following step is to determine how water moves on the surface in relation to the topography that characterizes the region in question The Flowdirections command calculates the drainage directions The exact identification of the natural path is limited due to the way in which the Earth s surface is discretized There are in fact only 8 possible directions in which the flow can be directed Flowdirections identifies the drainage direction by directing the flow along the line of maximum slope according to the D8 scheme In figure the adopted convention for the numbering of the 8 possible flow directions is represented The command to execute ish flowdirections from the main menu select HortonMachine gt Basic topographic attributes gt h flowdirections or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Basic topographic attributes Figure 3 6 shows the toolbar with the h flowdirections icon The legend of figure 3 8 highlights the fact that only 8 drainage direct2. 60 Bibliography 1 A Antonello S Franceschi E Ghesla R Rigon JGrass 2 0 Manuale Utente Maggio 2006 2 R Rigon E Ghesla C Tiso A Cozzini The Horton Machine a system for DEM analysis Dipartimento Ingegneria Civile ed Ambientale Maggio 2006 3 E Ghesla R Rigon JGrass2 0 Un tutorial per il trattamento di modelli digitali del terreno 10 111 es Le Dipartimento Ingegneria Civile ed Ambientale Maggio 2006 Bertoldi G R Rigon e T M Over Impact of watershed geomorphic characteristics on the energy and water budgets to appear Jour of Hydromet 2005 Rigon R Bertoldi G e T M Over GEOtop A distributed hydrological model with coupled water and energy budgets Jour of Hydromet to appear 2005 Zanotti F Endrizzi S Bertoldi G e R Rigon The GEOTOP snow module Hydrol Proc 18 3667 3679 2004 DOI 10 1002 hyp 5794 Tiso C Bertoldi G and R Rigon Il modello Geotop SF per la determinazione dell innesco di fenomeni di franamento e di colata Atti del Convegno Iterpraevent 2004 Riva del Garda 24 28 Maggio 2004 Zanotti F Endrizzi S Rigon R Il modulo di accumulo e scioglimento della neve in Geotop Atti del XXIX Convegno di Idraulica e Costruzioni Idrauliche Settembre 2004 Bertoldi G Rigon R Over T Geotop A Hydrological Balance Model Technical Description and Users Guide Dipartimento Ingegneria Civile ed Ambientale 2003 R Rigon G Bertoldi
3. Figure 3 10 h draindir Dialog box where the names of the input and output maps are specified In the example the drainage directions are calculated without fixing the hydrographic network beforehand select the normal method for the execution of the command in net fixed mode refer to the JGrass Tutorial 3 The required input data are the depitted DEM calculated with h pitfiller and the drainage directions map calculated with h flowdirection Furthermore it is necessary to assign a value to the A parameter this parameter assigns a weight to the correction made on the drainage directions the value assigned must be within 0 and 1 You must also choose the algorithm type used to carry out the calculation LAD least angular deviation which calculates the angular deviation with respect to the real flow path or LTD least transversal deviation which calculates the transversal deviation In the example the LAD method is used and the the A parameter was assigned a value of 1 in this way the calculated correction is fully taken into account For further details about the methods and the parameters please refer to The Horton Machine 2 and the article by Orlandini et al 2003 15 The results obtained are shown in figure 3 11 the corrected 19 3 Data Preprocessing for the Extraction of the Hydrographic Basin drainage directions and figure 3 12 the contributing areas L ha taal E uni j E a
4. Figure 3 11 h draindir Map of the corrected drainage directions The Flanginec Basin 20 3 Data Preprocessing for the Extraction of the Hydrographic Basin 1 0 3 0 6 0 7 5 10 0 30 0 50 0 75 0 100 0 300 0 500 0 G6924 0 113348 0 Figure 3 12 h draindir Total contributing areas map based on the corrected drainage directions The unit of mea surement is pixels The Flanginec Basin 2i 3 Data Preprocessing for the Extraction of the Hydrographic Basin 3 4 MarkOutlets At this stage it is necessary to mark all the outlets of the considered region on the drainage directions map Indeed by following the drainage directions you will eventually reach the border of the DEM These points on the border can in fact be the closing sections of a basin MarkOutlets identifies these points A convention has been adopted by which the drainage direction value of these points is replaced with 10 This operation is of fundamental importance for the calculation of other quantities During the following processing operations reference will always be made to the drainage directions map with marked outlets even if not specifically stated The command to execute is h markoutlets To do so from the main menu select HortonMachine gt DEM manipulation gt h markoutlets or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt DEM manipulation Figure 3 13 The h markoutlets icon Th
5. 1144 doi 10 1029 2002WR001639 2003 62
6. SPOT DU EA A RA ds IDA ee oe 53 24 DBO 222642222 ea en a A Len ee 55 020 Channel Networks es Des Laia e a ai eS an ek Yee ia 57 List of Figures 2241 22 2 3 2 4 2 9 2 6 2 7 2 8 2 9 2 10 2 11 2 12 2 13 2 14 2 15 2 16 3 1 3 2 3 3 3 4 3 0 3 6 3 0 3 8 3 9 3 10 3 11 Accessing a mapset from the main menu 4 La Seb ESS RRA De PERS SG 4 Accessing a mapset Troni the toolbar s a sars OM SO A Boke x 4 The dialog box for the selection of the workspace from a list of available ones 4 Importing digital data into JGrass R RT OR Re Re Bee 6 5 The icon to click in order to import digital data into JGrass 5 Importing digital data into JGrass sip RALE e EES wR 6 r in ascit Dialog box for the selection of the file to import to JGrass 6 The icon to click in order to view the console lt lt 7 KieJGrass Console su ona 5 Sod nn Lead on he Be See ore d 7 Execution of the r in ascit command from the command line o x A A FORTE ae A Bre ed 9 Fhe PERONI 000 pena cow dra de e e we Bow amp Be oe 10 Displaying a map in JGrass a Dia an a EO ee de we e 11 Selecting the toolbar with the d rast command icon 1 6 ee o 11 Displaying a map in JOTASS bas ia AA a a 12 The result of the importation process DEM of the Flanginec Basin 12 Executing the h pitfiller command Li Lins io ds dia li BOR 13 Executing the h pitfiller command a a aooaa 14 Eie hpitlle
7. T M Over and D Tamanini GEOTOP a distributed model of the hydrological cycle in the remote sensing era www cahmda wur nl Rigon_102 pdf Bertoldi G Rigon R Overt T M Un indagine sugli effetti della topografia sul ciclo idrologico con il medello GEOTOP Atti del XXVIII Convegno di Idraulica e Costruzioni Idrauliche Potenza pp 313 324 2002 Bertoldi G Dietrich W E Rigon R Il contributo del substrato roccioso e del suolo nella formazione del deflusso superficiale per saturazione nei bacini di testa non canalizzati Os servazioni sperimentali e simulazioni usando un modello idrologico distribuito Atti del XXIX Convegno di Idraulica e Costruzioni Idrauliche 2004 BIBLIOGRAPHY 13 Rinaldo A R Rigon e A Marani On what is explained by the form of the channel network In Entropy and Energy Dissipation in Water Resources V P Singh e M Fiorentino editors Kluver Dordrecth 379 399 1992 14 Laa Bertola P Bertoldi G Grisenti P Piva G Ragazzi M Righetti M Rigon R Salvaterra M Soppelsa G Tomazzolli V Integrated research on eutrophication processes on Caldonazzo lake Trento Italy Atti del Convegno Simposio Internazionale di Ingegneria Sanitaria e Ambientale Taormina 23 26 Giugno 2004 15 Orlandini S Moretti G Franchini M Path based methods for the determination of non dispersive drainage directions in grid based elevation models Water Resources Research Vol 39 NO 6
8. a threshold value is imposed on a map in the example the contributing areas map is used but one could use for example the map of area to slope ratio this map can be generated quite easily with the r mapcalc command for further details about this command refer to the JGrass 1 h extract network parameters formato della mappa grass mappa delle direzioni di flusso vidi flan_geotop formato della mappa grass mappa delle aree contribuenti dica test dine Sfoglia formato della mappa grass Sfoglia formato della mappa grass Tappa e valet class3 test flan_geotop di valore della soglia formato della mappa grass mappa della rete A O soglia sulle aree contribuenti O soglia sullo sforzo al fondo modalit di esecuzione fu soglia sullo sforzo al fondo solo nei siti convergenti Figure 3 32 h extractnetwork Dialog box where the names of the input and output maps are specified The result of the choices made is shown in figure 3 33 37 3 Data Preprocessing for the Extraction of the Hydrographic Basin Figure 3 33 h extractnetwork Map of the hydrographic network obtained by imposing a threshold value on the contributing areas The Flanginec Basin 38 4 Extraction of the Basin of Interest 4 1 WaterOutlets Once the hydrographic network has been identified with the aid of one of the methods described in the previous chapter it is possible to extract the catchment area of interest which
9. vi N Figure 3 27 Subdivision of the pixels by curvature The command to execute is h tc From the main menu select HortonMachine gt Hillslope analyses gt h tc or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Hillslope analyses The toolbar with the h tc icon is shown in figure 3 28 EEE Figure 3 28 The h tc icon 34 3 Data Preprocessing for the Extraction of the Hydrographic Basin The h tc command can also be executed from the console command line h tc quiet verbose version usage prof_curv lt prof_curv gt prof_curumapset lt prof_curumapset gt prof_curuformat lt prof_curvformat gt tang_curv lt tang_curv gt tang_curumap set lt tang_curumapset gt tang_curvformat lt tang_curvformat gt cp3map lt cp3map gt cp3mapmap set lt cp3mapmapset gt cp3mapformat lt cp3mapformat gt cp9map lt cp9map gt cp9Imapmapset lt cp9mapmapset gt cp9mapformat lt cp9mapformat gt th_prof lt th_prof gt th_tan lt th_tan gt usegui Example The execution of the command requires as input the curvature maps calculated with h curvatures The command s graphic interface where the names of the input and output maps are specified is shown in figure 3 29 The resulting output maps are shown in figures 3 30 and 3 31 rparameters formato della mappa grass mappa delle curvature e longitudinali
10. 1 Introduction 1 1 JGrass JGrass is a GIS based mainly on the analysis of raster and contains innovated algorithms for the analysis of landscape shapes necessary in order to delineate the hydrogeological risk zones In JGrass have been moreover implemented hillslope stability models of stability and floods generation models 1 2 GEOtop GEOtop 5 11 9 came to be through the will of Riccardo Rigon and in order to answer to a series of converging topics the desire to model evapotranspiration and eco hydrological phenomena slope stability 7 and slope hydrology in general 12 as well as snow cover evolution 6 8 GEOtop is a terrain based model it is in fact based on the use of digital terrain models and exploits the knowledge of the interactions between river basin morphology and basin processes It is a distributed model all the simulated variables are returned for every pixel of the basin It is a hydrological model it simulates all the components of the hydrological cycle not only the water budget but also the energy budget the two budget equations are coupled by the evapotranspiration and soil temperature terms the soil temperature term also controls the hydraulic conductivity of the soil and snow cover accumulation 6 The model has been applied in the study of the hydrological cycle of the Serraia Lake Trento 14 and to the data of the SGP97 experiment 5 the model was validated with these data A complete descript
11. 10 is the value that is conventionally assigned to basin outlets e 10 indicates the value that the points which fulfill the condition will be assigned in the new map e drainage directions map indicates that the points which do not fulfill the condition will be assigned the value of the corresponding points of the drainage directions map DT 5 Input Maps for GEOtop Example There now follows a calculation example a new drainage directions map will be created with a value of 10 assigned to the channel network In figure 5 22 there is an image of the graphic interface where the desired expression is inserted r mapcalc rparameters if net test m 2 10 dir test m map format grass hannel test 1 flan_geotop Browse format fluidturtleascii mapset flan_geotop REA map DS_Store tla leli v Il Ok Cancel Figure 5 22 The r mapcalc graphic interface In order to select the fluidturtleasci format for the output map in the format area select fluid turtleasci from the dropdown menu Click ok to start the calculation process Figure 5 23 shows the resulting map 58 5 Input Maps for GEOtop ha al Ex di wj o Figure 5 23 Map of the drainage directions with 10 assigned in correspondence of the channel network The Flanginec Basin 99 5 Input Maps for GEOtop
12. Calculation of the Network The network can now be calculated by imposing a threshold value on the product of the con tributing area and the gradient Click the h extractnetwork icon so that the command s graphic interface appears select the second execution mode and input the information necessary to the calculation The required input data are in order the drainage directions map the contributing areas map the slope map calculated with h gradient and the threshold value In this case as in the last the threshold value is chosen on the basis of the land area being analyzed and the map resolution Figure 3 22 shows the command s graphic interface where the names of the input and output maps are specified The result of the network extraction process is shown in figure 3 23 h extract network parameters formato della mappa grass mappa delle direzioni di flusso edita flan_geotop formato della mappa grass mappa delle aree contribuenti signi Gi formato della mappa grass mappa delle pendenze gradient test flan_geotop formato della mappa grass valore della soglia formato della mappa grass mappa della rete O soglia sulle aree contribuenti soglia sullo sforzo al fondo modalit di esecuzione E n n n n n soglia sullo sforzo al fondo solo nei siti convergenti Figure 3 22 h extractnetwork Dialog box where the names of the input and output maps are specified 29 3 Data Preprocessing for th
13. calculation is done by imposing a threshold on the contributing areas or magnitude In this method it is assumed that all pixels with a contributing area value greater than the threshold are channel pixels The choice of the threshold value is made in relation to the characteristics of the land surface and the resolution of the map pixel size If not enough information is available to make a reasonable choice for the threshold value it is advisable to make a number of attempts changing value each time and then confront the resulting network with an orthophoto of the basin h extract network parameters formato della mappa grass mappa delle direzioni di flusso milite flan_geotop formato della mappa grass mappa delle aree contribuenti eros ejer an_gectop Sfoglia formato della mappa grass Sfoglia formato della mappa grass valore della soglia formato della mappa grass fw soglia sulle aree contribuenti Fall n sp o soglia sullo sforzo al fondo modalit di esecuzione Fai A age soglia sullo sforzo al fondo solo nei siti convergenti Cancel Figure 3 17 h extractnetwork Dialog box where the names of the input and output maps are specified Example The method to use is chosen by selecting the corresponding option in the lower part of the dialog box as shown in figure 3 17 The required input data are in order the drainage directions map 20 3 Data Preprocessing for the Extracti
14. ee a Sk 1 2 Preliminary Operations 3 Za osaat ono GLASS 0 a PALE OH n 3 2 2 Creating of a New Location 0 5 a a bd dena ee BA Oe Je egw Le 3 2 3 Importing the DEM Digital Elevation Model 0 o 5 Lod Exile EA AN sra BAR Ge o oo Se eG 6 2 3 2 Execution from the Command Line 0 7 2 4 Setting Up the Active Working Region 000 eee eee 8 2 STORM te AotW on Oh oh uh eae Hew he a Ee et ie E de ew a 9 2 0 Viewing the Imported Map e e e 11 3 Data Preprocessing for the Extraction of the Hydrographic Basin 13 Sel Pile 22 anadir ge e RR ee 13 Seli Example sg 2 5 do Bae oe oe A e hae AA 14 a FOWD ECONS 4 4 28 4 4h we Beh e o e is dd Pa 16 dz o AA A et deri 17 peo A A A ha 18 A A A e e 19 ds A AI 22 oul EXI ee 4 4 45 pi bee ee ds de LL A SE BR 22 oo JeextrachNectwOrk a eara abi aL ARL SSO oS AA 24 3 5 1 Determination of the Network Using the Contributing Areas or the Magnitude 25 3 5 2 Determination of the Network Using the Contributing Areas and the Slopes 27 3 5 3 Determination of the Network Using the Curvatures 31 CONTENTS 4 Extraction of the Basin of Interest 39 Ad WaterQuvlets ds sulla ti lr eterea 39 5 Input Maps for GEOtop 43 5 1 Format of the Input Files bs et bd e lea PAT n BOS 43 5 2 Creation of the Input Maps for GEOtop ooa aa a a 44 E o A anse ehi ARIAL LAS i 48 922 INaDIa EA plain iii es arpa e das A 51 O29
15. is only a part of the territory analyzed up to this point and proceed to its geomorphological analysis The program for the extraction of the basin requires the closing section to be specified The closing section must belong to the channel network in other words it must be a channel pixel The command to execute is h wateroutlet From the main menu select HortonMachine gt DEM manipulation gt h wateroutlet or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt DEM manipulation Figure 4 1 The h wateroutlet icon The h wateroutlet command can also be executed from the console command line h wateroutlet quiet verbose version usage drainage lt drainage gt basin lt basin gt northing lt northing gt easting lt easting gt extractmap lt extractmap gt usegui Example To execute the command click the corresponding icon and so display the command s graphic interface The required input data are the drainage directions map and the coordinates of the closing section The preliminary operation is to identify the closing section of the basin to be extracted If its coordinates are already known it is sufficient to input them in the appropriate text boxes In the case that the coordinates are not known it will be necessary to view the hydrographic network before launching h wateroutlet Input the name of the hydrographic network map in the 4 Extraction of
16. listed have been calculated already however they will need to be trimmed along the border of the mask of the extracted subbasin so as to carry out an analysis only of the basin of interest This operation can be carried out with the r mapcalc command To execute r mapcalc from the main menu select Raster gt Operations on raster maps gt r mapcalc 44 5 Input Maps for GEOtop In order to carry out the required calculations you will need to input an expression of the type new_map if condition fulfilled then assign null value else assign value from map to trim the drainage directions map the expression to input is dir test m if m null null dir test in this way a map is generated in the specific case called dir test m with a null value in corre spondence of a null value in the map called m m is the mask see chapter 4 and so the new map has null values outside the basin of interest in the other points of the new map within the basin of interest the value assigned is that of the drainage directions map dir test The r mapcalc graphic interface is shown in figure 5 1 while figure 5 2 shows the resulting map r mapcalc parameters if m null null dir test formato della mappa grass Sfoglia dir test m flan_geotop format grass mapset flan_geotop map dir test ala eli lly l lr Figure 5 1 r mapclac Command window where the expressio
17. prof test flan_geotop formato della mappa grass mappa delle curvature tangenziali tang test flan_geotop soglia sulla curvatura 0 001 longitudinale soglia sulla curvatura 0 001 tangenziale formato della mappa grass mappa tc 3 valori class3 test flan_geotop _Sfoglia_ formato della mappa grass mappa tc 9 valori ced ai an_geotop Sfoglia OK Cancel e Figure 3 29 h tc Dialog box where the names of the input and output maps are specified 39 3 Data Preprocessing for the Extraction of the Hydrographic Basin Planar planar sas convex planar sites concave planar sites planar convex sites convex convex sites fon GE VeE DOnVves sas planarconcave sites DOMNVex Doncave sea concave lt oncave Biles Figure 3 30 h tc Map of the topological classes with classification according to 9 categories concave sitas E planar sites O convar sites Figure 3 31 h tc Map of the topological classes reclassified according to 3 categories The concave sites are marked in yellow the convex sites are marked in red and the planar ones are in blue 36 3 Data Preprocessing for the Extraction of the Hydrographic Basin Extraction of the Hydrographic Network Once the concave convex and planar sites have been distinguished the extraction of the hydro graphic network is possible using the third available method In this case also
18. test flan_geotop _Sfoglia formato della mappa grass mappa da estrarre pit test m flan_geotop Sfoglia il coordinate con mouse coordinata nord 5111657 0 coordinata est 1636434 5 Il net test flan_geotop Sfoglia 6 maschera del bacino estratto im OK Cancel 4127 om o Est 1636802 Nord 5111390 Elevazione 0 flan_geotop Lettura della mappa net test Memoria diponibile 251MB a A Figure 4 2 h wateroutlet Dialog box requiring the names of the input maps and the closing section coordinates The blue circle marks the area where the closing section was chosen The red circle shows the value of the network map in correspondence of the selected point the value is 2 therefore the point is effectively part of the channel network 40 4 Extraction of the Basin of Interest Figure 4 3 h wateroutlet Mask of the extracted subbasin superimposed onto the channel network map The Flanginec Basin 704 1018 920 7074 1065 4031 1201 0087 1336 6143 1472 2106 1607 8254 1743 4312 1879 0367 1969 4406 2105 0464 Figure 4 4 h wateroutlet Map of the extracted subbasin The Flanginec Basin Al 4 Extraction of the Basin of Interest 42 5 Input Maps for GEOtop Once the basin of interest has been extracted it is possible to extract the maps necessary for the executi
19. the Basin of Interest dialog box as shown in figure 4 2 in the example the network map is net test The program allows you to click on the map and returns the value of the selected point The closing section of the basin is necessarily part of the channel network it therefore must return a value of 2 according to the adopted convention channel sites have a value of 2 to distinguish them from slope sites Figure 4 2 shows the program window The WaterOutlets program generates two output files one containing a mask of the extracted basin that is a raster with a value of 1 in correspondence of the extracted basin and a null value beyond the basin limits and a second file containing a map trimmed along the mask boundary It is possible to choose the map to trim from among all the maps generated previously by inputting the map name in the appropriate space beside the string the map to extract In this example case it was decided to extract the depitted DEM calculated with h pitfiller The program will assign the trimmed map a compound name made up of the name of the original map and the name of the mask in the example the resulting map is called pit test m Figure 4 3 shows the mask of the Flanginec Basin superimposed onto the hydrographic network map figure 4 4 shows the trimmed DEM h wateroutlet File Visualizza Gis Raster Vettoriali Extra Horton parameters y D i Q RE formato della mappa grass flusso mdir
20. to the map in those points where the real value is not known When the program comes across this value it omits the corresponding point from the calculations In this case the novalue value is 9999 0 The 1 before it means that the novalue value is less than all other values contained in the raster To understand what a novalue is it is worth remembering for example that when the basin of interest was extracted in chapter 4 the points external to the basin of interest were eliminated in these points the map has no value The third block contains the number of rows and columns of the data matrix in the example there are 640 rows and 580 columns In the example the data matrix itself is not shown For further details please refer to The Horton Machine 2 5 2 Creation of the Input Maps for GEOtop GEOtop requires the following input maps for its execution to be possible e depitted elevation map h pitfiller e drainage directions map h flowdirections h draindir e contributing areas map h draindir e channel network map h extractnetwork e gradient map h gradient e map of the slopes calculated along the drainage directions h slope e map of the laplacian nabla operator h nabla e aspect map h aspect e map of the distance to outlet of every point h D20 e map of the drainage directions with a value of 10 in correspondence of the channel network Channel Network Some of the maps
21. 5330 Est 1632957 Nord 5113527 Elevazione 0 Figure 2 9 The JGrass Console To execute programs from the command line you need to know the syntax to use If you are unsure of the exact syntax it is sufficient to type command name usage and then hit enter the string to use will appear on the console The execution of r in asci from the comand line is shown in figure 2 10 Figure 2 10 Execution of the r in ascit command from the command line 2 Preliminary Operations quiet allows you to follow the evolution of the command verbose shows the entire evolution of the command and the internal console messages this option can also be activated with the information icon of the console e usage allows you to view the syntax that is to be used in order to execute a command you must write r in ascii usage this string must not be included for the execution of the command e ascit lt ascii gt the map to be imported the string lt asci gt is to be replaced with the name of the map to be imported e map mapset lt map mapset gt name to be assigned to the new map and the mapset where it will be saved the string lt map mapset gt is to be replaced with the name of the map map and the mapset mapset where it is to be saved e novalue lt novalue gt value to be assigned to the null value points this term is not strictly necessary if it is not specified
22. A Tutorial for Preparing GEOtop Input Files with 704 1518 029 7074 1065 4031 1201 0087 1336 6143 1472 2198 1607 8254 171434312 1879 0367 1866 4406 Grass Erica Ghesla Riccardo Rigon 2105 0461 IS UNIVERSIT DEGLI STUDI DI TRENTO Dipartimento di Ingegneria Civile e Ambientale Trento April 2006 ISBN 10 88 8443 153 0 ISBN 13 978 88 8443 153 0 Translation by Joseph E Tomasi Readme This ebook was written by Erica Ghesla and Riccardo Rigon University of Trento Department of Civil and Environmental Engineering It is distributed according to the CREATIVE COMMONS deed Attribution NoDerivs 2 5 According to this license type you are free to e copy distribute display and perform the work e to make commercial use of the work Under the following conditions e Attribution You must attribute the work in the manner speciied by the author or licensor e No Derivative Works You may not alter transform or build upon this work e For any reuse or distribution you must make clear to others the license terms of this work Any of these conditions can be waived if you get permission from the copyright holder Your fair use and other rights are in no way affected by the above This is a human readable summary of the Legal Code the full license that can be consulted at http creativecommons org licenses by nd 2 5 legalcode Contents 1 Introduction 1 LI A tea Rene ent 1 Pr GEOWD rabarbaro Se
23. M Digital Elevation Model The first necessary operation is to import the digital terrain data of the area that you wish to analyze into JGrass The imported DEM is the basis from which the maps necessary for the execution of GEOtop are generated The command to execute is r in ascii from the main menu select Gis gt Import Export Tools as shown in figure 2 4 009 JGRASS Java GRASS Build 2 File Visualizza K Raster Vettoriali Extra HortonMachine Aiuto Strumenti di importazione esportazione Q a e E Ey Strumenti di importacone esartacon Li Figure 2 4 Importing digital data into JGrass In so doing a new toolbar appears shown in figure 2 5 To view the importation command dialog box click on the icon as shown in figure 2 5 Figure 2 5 The icon to click in order to import digital data into JGrass The command can also be executed by selecting Gis gt Import Export Tools gt r in ascti as shown in figure 2 6 2 Preliminary Operations 606 JGRASS Java GRASS Build 2006013 File Visualizza Raster Vettoriali Extra HortonMachine Aiuto Ss Strumenti di importazione esportazione Q Q e Q Strumenti della regione b Strumenti di importazione esportazione Figure 2 6 Importing digital data into JGrass 2 3 1 Example Let us import the DEM of interest it is the starting point for the generation of the input files necessary for the execution of t
24. SCC hele ty he Ge Been Gt Wah Meade ny DLE 37 h extractnetwork Map of the hydrographic network obtained by imposing a threshold value on the contributing areas The Flanginec Basin LL 38 1V 4 1 4 2 4 3 4 4 5 1 9 2 5 3 5 4 5 9 5 6 O 9 8 9 9 5 10 5 11 5 12 5 13 5 14 5 15 5 16 5 17 5 18 5 19 5 20 5 21 9 22 LIST OF FIGURES The wateroutlel ICO su e coses asia da a o a aa d i 39 h wateroutlet Dialog box requiring the names of the input maps and the closing section coordinates The blue circle marks the area where the closing section was chosen The red circle shows the value of the network map in correspondence of the selected point the value is 2 therefore the point is effectively part of the channel MELIDE lt A E e RAS Ee cl amp Fee 40 h wateroutlet Mask of the extracted subbasin superimposed onto the channel network map Ihe Flanginec DOSING pei LE e a OES ARR Oe 41 h wateroutlet Map of the extracted subbasin The Flanginec Basin 41 r mapclac Command window where the expression to be calculated is input 45 h draindir Map of the corrected drainage directions of the extracted basin The FLONGINEE BASTE 4 5 vba Pilla grab pd fe hi rd t 46 h draindir Total contributing areas map of the extracted basin The Flanginec Basin 46 h extractnetwork Map of the channel network The Flanginec Basin 47 h gradient Map of the gradient of the extracted basin T
25. arameters Dati della regione attiva E Modifica nord 5116490 0 sud 5110090 0 ovest 1635940 0 est 1641740 0 righe 640 colonne 580 nsres 10 0 ewres 10 0 formato della mappa grass flan_geotop Seleziona la mappa DTM Regione di default E Modifica Setta ad una mappa Estendi con mappa Celle attive nord 5116490 0 sud 5110090 0 ovest 1635940 0 est 1641740 0 nsres 10 0 righe 640 colonne 580 formato della mappa grass Y registra i dati della regione attiva mapset di default Y registra i dati della regione di default Figure 2 12 The g region dialog box 10 2 Preliminary Operations 2 5 Viewing the Imported Map Once the map has been imported and the working region has been set it will be possible to view the map and verify that all the operations have been carried out correctly To view the imported map from the main menu select View gt Display a raster map as shown in figure 2 13 tit Gis Raster Vettoriali Extra HortonMact y 3 Strumenti di visualizzazione delle mappe Q ey Visualizza una mappa raster Visualizza una mappa di punti Visualizza un layer da Postgis 5 Cancella le mappe dal display I Rebuild map image at current zoom Figure 2 13 Displaying a map in JGrass The map can also be viewed by selecting View gt Map Display Tools as shown in figure 2 14 In this case a new toolbar appears click on the first icon a display wiza
26. corresponding icon from the toolbar that appears by checking HortonMachine gt DEM manipulation as shown in figures 3 2 and 3 3 JGRASS Java GRASS Build 200601310853 Modifica DEM Attributi del bacino Analisi del reticolo idrografico Analisi dei versanti Indici e relazioni idro geomorfologiche Analisi relative al bacino Statistiche Hydro geomorphology Modifica DEM E Attributi del bacino k Analisi del reticolo idrografico b ds hn elimina i buchi dal DTM Analisi dei versanti P h wateroutlet Indici e relazioni idro geomorfologiche gt Analisi relative al bacino gt h splitsubbasin Statistiche gt Hydro geomorphology gt Figure 3 1 Executing the h pitfiller command 3 Data Preprocessing for the Extraction of the Hydrographic Basin JGRASS Java GRASS Build 20 File Visualizza Gis Raster Vettoriali Extra Mire Aiuto Attributi del bacino Analisi del reticolo idrografico Analisi dei versanti Indici e relazioni idro geomorfologiche Analisi relative al bacino Statistiche Hydro geomorphology Modifica DEM Attributi del bacino Analisi del reticolo idrografico Analisi dei versanti Indici e relazioni idro geomorfologiche Analisi relative al bacino Statistiche Hydro geomorphology TOY Y Y Y FF Yo Figure 3 2 Executing the h pitfiller command Figure 3 3 The h pitfiller icon In both cases a dialog box will appear on display From dialog box you select the
27. e Extraction of the Hydrographic Basin Figure 3 23 h extractnetwork Map of the hydrographic network obtained by imposing a threshold on the product of the contributing areas and the gradient The Flanginec Basin 30 3 Data Preprocessing for the Extraction of the Hydrographic Basin 3 5 3 Determination of the Network Using the Curvatures The hydrographic network is extracted considering only the concave points as belonging to the network As in the first case a threshold value is imposed on a map To identify the concave points it is necessary to calculate the curvatures tangent profile and planar and then execute Topological classes in order to distinguish between concave planar and convex points Curvature This program calculates the planar profile and tangent curvatures of an area The curvatures represent the deviation of the gradient vector per unit length in radians along particular curves traced on the surface under study For further details please refer to The Horton Machine 2 The command to execute is h curvatures from the main menu select HortonMachine gt Basic topographic attributes gt h curvatures or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Basic topographic attributes The toolbar with the h curvatures icon is shown in figure 3 24 The h curvatures command can also be executed from the console command line h curvatures quiet
28. e directions The Flanginec Basin 50 5 Input Maps for GEOtop 5 2 2 Nabla Laplacian The Laplacian of the elevation V 2 will now be calculated The program gives the choice between either calculating the Laplacian in every point of the map or generating a map that distinguishes between concave sites V z lt 0 convex sites V7z gt 0 and planar sites V7z lt e by imposing a threshold value e to the value of the Laplacian For further details please refer to The Horton Machine 2 GEOtop requires the site classes and not the specific values of the Laplacian in the various parts of the map The command to execute is h nabla From the main menu select HortonMachine gt Basic topographic attributes gt h nabla or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Basic topographic attributes The toolbar with the h nabla icon is shown in figure 5 12 Figure 5 12 The h nabla icon The h nabla command can also be executed from the console command line h nabla quiet verbose version usage pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt nabla lt nabla gt nablamapset lt nablamapset gt nablaformat lt nablaformat gt mode lt mode gt th_nabla lt th_nabla gt usegut Example The distinction between concave and convex sites is determined in this specific case by imposing a threshold value e of 0 001 T
29. e h markoutlets command can also be executed from the console command line h markoutlets quiet verbose version usage flow lt flow gt inmapset lt inmapset gt inputformat lt inputformat gt mflow lt mflow gt mflowmapset lt mflowmapset gt mflowformat lt mflowformat gt usegut 3 4 1 Example The command s graphic interface is shown in figure 3 14 The drainage directions map is required as input The result is shown in figure 3 14 22 3 Data Preprocessing for the Extraction of the Hydrographic Basin h markoutlets CCC r par ameters formato della mappa grass mappa delle direzioni di z flusso dir test flan_geotop Sfoglia formato della mappa grass mappa con uscite segnate mdir test flan_geotop Sfoglia OK Cancel gt _A___ Figure 3 14 h markoutlets Dialog box where the names of the input and output maps are specified Figure 3 15 h markoutlets Corrected drainage directions map with the region outlets marked The Flanginec Basin 23 3 Data Preprocessing for the Extraction of the Hydrographic Basin 3 5 ExtractNectwork The hydrographic network can now be extracted with one of the three methods available The first method is based on the magnitude or the total contributing area the second is based on the product of the total contributing area and the gradient the third is based on the curvatures Depe
30. ears by checking HortonMachine gt Network related measures The toolbar with the h D2O icon is shown in figure 5 18 Figure 5 18 The h D2O icon The h D20 command can also be executed from the console command line h D20 quiet verbose version usage flow lt flow gt flowmapset lt flowmapset gt flowformat lt flowformat gt dist2outlet lt dist2outlet gt dist2outletmapset lt dist2outletmapset gt dist2outletformat lt dist2outletformat gt mode lt mode gt usegui Example To execute the command and calculate the number of pixels that separates each point from the basin outlet the topological distance option must be selected An image of the graphic interface where the input and output map names are specified is shown in figure 5 19 Figure 5 20 shows a map of the distances to the outlet 59 5 Input Maps for GEOtop parameters formato della mappa grass mappa delle direzioni di cre flusso dir test m flan_geotop formato della mappa grass mappa di dist2outlet D20 testm flan_geotop O distanza semplice gt opzioni d esecuzione O distanza topografica Figure 5 19 h D20 Dialog box where the names of the input and output maps are specified Figure 5 20 h D20 Map of the distance of each point from the basin outlet The Flanginec Basin 56 5 Input Maps for GEOtop 5 2 5 Channel Network Final
31. ed to calculate the slopes along the drainage directions these differ from the slopes calculated with h gradient as specified in The Horton Machine 2 The command to execute is h slope From the main menu select HortonMachine gt Basic topographic attributes gt h slope or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Basic topographic attributes The toolbar with the h slope icon is shown in figure 5 6 Figure 5 6 The h slope icon The h slope command can also be executed from the console command line h slope quiet ver gt bose version usage pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt flow lt flow gt flowmapset lt flowmapset gt flowformat lt flowformat gt slope lt slope gt slopemapset lt slopemapset gt slopeformat lt slopeformat gt useguil Example The command is executed in the way described above however the format of the output maps must be specified The required input maps are the DEM and the drainage directions map trimmed along the border mask of the extracted catchment basin To select the output format in the third line of the dialog box were the name of the slope map is required click Browse From the dropdown menu of the window that appears select the fluidturtleasci format and click next Type the name of the map to be created the input box will become active once a mapset
32. has been selected Some example images now follow 48 5 Input Maps for GEOtop h slope parameters formato della mappa grass raster delle elevazioni depittato pit testm 1 fian_geotop formato della mappa grass mappa delle direzioni di flusso dir test m_ 1 flan_geotop formato della mappa grass mappa della pendenza flan_geotop Figure 5 7 h slope Dialog box where the names of the input and output maps are specified ODO Procedura guidata per scegliere una nuova mappa grass hed Next gt Figure 5 8 h slope Choosing the output map format The Flanginec Basin Procedura guidata per scegliere una nuova mappa fluidturtleascil Y grass grassascii esriasciigrid O A_N ANNNToc_ co VV Y SnxnNnNT lt Indietro Avanti gt Annulla a LA Figure 5 9 h slope Choosing the output map format The Flanginec Basin 49 5 Input Maps for GEOtop 0 Procedura guidata per scegliere una nuova mappa E ad Location test_corso flan_geotop slope test ml aflan_geotop lt Indietro Fine Annulla i Figure 5 10 h slope Naming the output map to be generated The Flanginec Basin The map will be created and saved in a directory called fluzdturtleascii in the mapset of origin The file can be used directly in GEOtop A plot of the resulting map is shown in figure 5 11 Figure 5 11 h slope Map of the slopes calculated along the drainag
33. he Flanginec Basin 47 FREDS lODEN aa gua Aa e ie ie A a A 48 h slope Dialog box where the names of the input and output maps are specified 49 h slope Choosing the output map format The Flanginec Basin 49 h slope Choosing the output map format The Flanginec Basin 49 h slope Naming the output map to be generated The Flanginec Basin 50 h slope Map of the slopes calculated along the drainage directions The Flanginec Pie e est da amp dee AR LEDA LR A ERROR 50 TREO MabDLA TOON an oa e o A e ce o amp a a ew ee a 51 h nabla Dialog box where the names of the input and output maps are specified 52 h nabla Map of the Laplacian distinguishing between concave convex and planar sites The Flangin ec Basme 4 uo n E ele Ta ae 8 ee a 52 TREMA CONS ais Shy cis E A RE wa Gwe eae A ara 53 h aspect Dialog box where the names of the input and output maps are specified 54 h aspect The aspect map The Flanginec Basin LL 54 Pieh D20O4wcop asini tea Bo ee arena 55 h D20 Dialog box where the names of the input and output maps are specified 56 h D20 Map of the distance of each point from the basin outlet The Flanginec Basin 56 Te CMap CO Sat aa A Ret 57 The t mapcale graphic interface co eaa a lea EL I 58 LIST OF FIGURES 5 23 Map of the drainage directions with 10 assigned in correspondence of the channel network The Flanginee Bast sibi ius aa bn E vi
34. he GEOtop program Figure 2 7 shows the dialog box where the file to be imported is selected Click on the Browse button to select the file to be imported The program requires you to specify the value that has been assigned to the null value points of the map to be imported in the example it is 9999 when the value of a point of the map is unknown these are assigned either a number or a symbol so that they can be recognised In many cases the asterisk is used or another symbol In these cases JGrass requires you to specify the null value so that it can distinguish it from points of known value Specify a name to give to the imported map within JGrass Click ok in order to execute the command In this way the map will be imported r in ascii parameters file ascii da importare Jeclipse workspace jgrass1 DTM browse valore da convertire in null durante l importazione 9999 0 nome della nuova formato della mappa grass mappa sfoglia gt da importare DTM flan_geotop ok cancel Figure 2 7 r in ascti Dialog box for the selection of the file to import to JGrass 2 Preliminary Operations 2 3 2 Execution from the Command Line The JGrass commands can be executed directly from the command line without viewing the dialog box To view the console click the icon as shown in figure 2 8 Figure 2 8 The icon to click n order to view the console 1 3
35. he value itself is to be chosen in reference to the local topography In order to obtain a map that distinguishes the three classes the command must be executed in CLASSES mode The dialog box where the names of the input and output maps are specified is shown in figure 5 13 The result of the process is shown in figure 5 14 ol 5 Input Maps for GEOtop h nabla parameters formato della mappa grass raster delle elevazioni a depittato pit testm flan_geotop formato della mappa grass mappa del laplaciano nabla test m flan_geotop CLASSI VALORI REALI soglia sul laplaciano Figure 5 13 h nabla Dialog box where the names of the input and output maps are specified Figure 5 14 h nabla Map of the Laplacian distinguishing between concave convex and planar sites The Flanginec Basin 92 5 Input Maps for GEOtop 5 2 3 Aspect At this stage the aspect of the local area must be determined The aspect is defined as the angle of inclination of the gradient calculated in degrees For further details about the method please refer to The Horton Machine 2 The command to execute is h aspect From the main menu select HortonMachine gt Basic topographic attributes gt h aspect or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Basic topographic attributes The toolbar with the h aspect icon is shown in figure 5 15 Figu
36. ing region and how to set it up All these concepts are explained in detail in the JGrass User Manual 1 there follows here only a brief summary 2 2 Creating of a New Location Once the program has been installed it is necessary to create a workspace also called location The location will contain information relative to the region and the processed maps will be saved therein For instructions on how to create a new location please refer to the JGrass User Manual 1 Once the location has been created it is possible to access the new workspace from the main menu select File gt Load Workspace or else click directly on the icon as shown in figure 2 2 In both cases a dialog box will appear from which to select a working mapset Click on the name of the desired working location in the example shown the location is flan_geotop and then click the Finish button An example of this operation is shown in figure 2 3 The workspace will appear as partially shown in figure 2 4 2 Preliminary Operations ie Aiuto Cdi Nuovo ambiente di lavoro Apri ambiente di lavoro Figure 2 1 Accessing a mapset from the main menu Figure 2 2 Accessing a mapset from the toolbar Selezionare l ambiente di lavoro da usare p JGRASS Test Database flan_geotop Figure 2 3 The dialog box for the selection of the workspace from a list of available ones 2 Preliminary Operations 2 3 Importing the DE
37. input map to be used for the calculation and choose a name for the output map that will be calculated as shown in figure 3 3 The h pitfiller command can also be executed from the console command line h pitfiller quiet verbose version usage elevation lt elevation gt inmapset lt inmapset gt inputformat lt inputformat gt pit lt pit gt outmapset lt outmapset gt outputformat lt outputformat gt usegut 3 1 1 Example There now follows an example of application to a real situation The DEM that was previously imported is now required as input In the specific case the file to input is called DTM The depitted output file is pit test The string flan_test which follows the map name refers to the working location By clicking ok the h pitfiller command is launched For greater clarity during map management it is advised to give the maps names that refer to the command used to produce them At this point it is possible to view the resulting map pit_test For a description of the display method and and for the creation of a map legend please refer to the JGrass Manual 1 Figure 3 5 shows the 14 3 Data Preprocessing for the Extraction of the Hydrographic Basin resulting map h pitfiller r parameters formato della mappa grass raster delle elevazioni DTM flan_geotop formato della mappa grass raster delle elevazioni depittato pit testl flan_geotop
38. ion of the model is found in 5 and 13 while 4 contains an analysis of the effects of topography in the redistribution of hydrological flows For further information please refer to the literature listed in the bibliography and if necessary to Rigon s presentation 2004 10 The present tutorial has been written to facilitate the procedures of preparation of the geo graphic spatial inputs for the hydrological model GEOtop Through the use of the GIS JGrass it is possible to run easely advance analyses for the creation of maps which water drainage direc tions total contributing areas channel network map of the convexities slopes aspect and others important geomorfological parameters These quantities are necessary inputs for the simulation of the hydrological cycle by mass and energy budgets 1 Introduction 2 Preliminary Operations 2 1 Installation of JGrass The JGrass installation package can be found at the www hydrologis com web site in the JGrass section For information about installation please refer to the aforementioned web site the JGrass User Manual 1 and the JGrass Wiki site For particular problems you can consult the mailing list the address is available at the www hydrologis com web site The first steps to take include e understanding the JGrass interface e understanding what a location is e understanding what a digital terrain model DTM is e understanding what is the active work
39. ions are possible Figure 3 6 The h flowdirections icon The h flowdirections command can also be launched from the console command line h flowdirections quiet verbose version usage pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt flow lt flow gt flowmapset lt flowmapset gt flowformat lt flowformat gt usegui 16 3 Data Preprocessing for the Extraction of the Hydrographic Basin 3 2 1 Example In the example that follows you will be shown how to launch the command The depitted DEM calculated with h pitfiller paragraph 3 1 is required as input Figure 3 7 shows the dialog box where the names of the input and output maps are specified h flowd irections parameters formato della mappa grass raster delle elevazioni depittato pit test flan_geotop Sfoglia formato della mappa grass mappa delle direzioni di flusso flow test flan_geotop Sfoglia OK Cancel Figure 3 7 h flowdirections Dialog box where the names of the input and output maps are specified Once the processing has finished it is possible to view the resulting output map figure 3 8 Lr 2 Tal p qm j ve E Figure 3 8 h flowdirections Drainage directions map The Flanginec Basin 17 3 Data Preprocessing for the Extraction of the Hydrographic Basin 33 DrainDir The method used in Flowdirection
40. ly due to the particular way in which GEOtop works it is necessary to mark the channel pixels as if they were closing sections of the basin this is done by creating a map with a value of 10 in correspondence of the channel network and the corresponding values of the drainage directions in all the other points of the basin This operation is carried out with the r mapcalc command which allows you to carry out mathematical operations on the maps To call up the r mapcalc dialog box from the main menu select Raster gt Operations on raster maps gt r mapcalc it is possible to launch the command by clicking the icon that appears by checking Raster gt Raster Map Tools figure 5 21 shows the toolbar from which to select the r mapcalc icon E UN 2 Figure 5 21 The r mapcalc icon To obtain the desired map it is necessary to input an expression of the following type new map if channel netweork map 2 10 drainage directions map an explanation of the different terms of the expression now follows e if condition then else if the condition is met then the first value is assigned otherwise the second value is assigned The condition is checked in every point of the channel network map e channel network map 2 this indicates that only points belonging to the channel network are being sought these are identified by the value 2 as explained in paragraph 3 18 these will be assigned the value 10 in the new map
41. mand line g region quiet verbose version usage west lt west gt east lt east gt north lt north gt south lt south gt map lt map gt resolution lt resolution gt default usetoolbar usegui 2 4 1 Example To set up the working region click the icon as explained in paragraph 2 11 The name of the map of interest can be input directly into the specific text box which is found in correspondence of the string map selection or else by clicking the Browse button and then selecting from the list of available maps Once a map has been selected click the set region from map button in order to set up the region The information relative to the region will then appear as shown in figure DI It is important that a lot of attention be given to this operation as all the calculations that will be carried out afterwards depend on a correct setup of the working region It is necessary to verify that the numbers which indicate the resolution found in the text boxes beside the strings nsres pixel dimension in a north south direction and ewres pixel dimension in an east west direction be integers If necessary modify the coordinates of the region boundary so as to obtain whole number values for the resolution the coordinates can be modified so that the difference between the North South and the East West coordinates be multiples of the pixel resolution 2 Preliminary Operations p
42. n Te Topological Classes classifies a land surface area subdividing it into 9 topographic classes on the basis of the profile and planar curvature see The Horton Machine 2 From these 9 classes the program then reclassifies the map grouping the planar concave and convex sites into three categories The program requires you to impose a threshold value on the profile curvature and the tangent curvature those sites with an absolute curvature value less than the value of the threshold are considered planar In general in order to determine this value experiments are carried out for every basin depending on the topography The adopted conventions for the description of the topological classes are e 10 planar sites parallel e 20 convex sites parallel e 30 concave sites parallel e 40 planar sites divergent e 50 convex sites divergent e 60 concave sites divergent e 70 planar sites convergent e SO convex sites convergent e 90 concave sites convergent for the map where the 9 classes are grouped into 3 fundamental ones the adopted conventions are the following e 15 concave sites classes 30 70 90 e 25 planar sites class 10 e 35 convex sites classes 20 40 50 60 80 33 3 Data Preprocessing for the Extraction of the Hydrographic Basin Figure 3 27 shows the subdivision of the map pixels according to the adopted convention Contour hne
43. n to be calculated is input Once the drainage directions map of the basin of interest has been obtained it is necessary to mark the basin outlet This is done with the h markoutlets command using the new drainage directions map just calculated as input In order to trim the other maps you only need to repeat the procedure that has just been described Once the maps have been trimmed the commands that have not yet been described can be pre sented These commands allow you to calculate a set of parameters that describe the hydrographic basin 45 5 Input Maps for GEOtop ho w gt na Figure 5 2 h draindir Map of the corrected drainage directions of the extracted basin The Flanginec Basin There now follows a series of maps that were calculated earlier but that have been recalculated considering only the basin of interest 1 0 3 0 5 0 7 5 10 0 30 0 50 0 75 0 100 0 300 0 500 0 25850 0 51200 0 Figure 5 3 h draindir Total contributing areas map of the extracted basin The Flanginec Basin 46 5 Input Maps for GEOtop Figure 5 4 h extractnetwork Map of the channel network The Flanginec Basin 0 0 0 19415843 0 38831684 0 5824753 0 7766337 0 97079206 1 1649505 1 3591089 1 5532674 1 7474258 10415842 pl Figure 5 5 h gradient Map of the gradient of the extracted basin The Flanginec Basin 47 5 Input Maps for GEOtop 5 2 1 Slope We now proce
44. nding on the method chosen different additional maps need to calculated The resulting channel network map will have a value of 2 in correspondence of the network and a null value in the other points The command to execute is h extractnetwork from the main menu select HortonMachine gt Network related measures gt h extractnetwork or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Network related measures Figure 3 16 shows the toolbar containing the h extractnetwork icon Figure 3 16 The h extractnetwork icon The h extractnetwork command can also be executed from the console command line h extractnetwork quiet verbose version usage prof_curv lt prof curv gt prof_curumapset lt prof_curumapset gt prof_curuformat lt prof_curvformat gt tang_curv lt tang_curv gt tang_curumapset lt tang_curumapset gt tang_curvformat lt tang_curvformat gt cp3map lt cp3map gt cp8mapmapset lt cp3mapmapset gt cp3mapformat lt cp8mapformat gt cp9map lt cp9map gt cp9mapmapset lt cp9mapmapset gt cpoImapformat lt cpImapformat gt th_prof lt th_prof gt th_tan lt th_tan gt usegut There follow some examples of the execution of the command using the three available methods 24 3 Data Preprocessing for the Extraction of the Hydrographic Basin 3 5 1 Determination of the Network Using the Contributing Areas or the Magnitude The
45. ne h draindir quiet verbose version usage pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt flow lt flow gt flowmapset lt flowmapset gt flowformat lt flowformat gt net_fixed lt net_fixed gt net_firedmapset lt net_firedmapset gt net_fixedformat lt net_fixedformat gt draindir lt draindir gt draindirmapset lt draindirmapset gt draindirformat lt draindirformat gt tca lt tca gt 18 3 Data Preprocessing for the Extraction of the Hydrographic Basin Htcamapset lt tcamapset gt tcaformat lt tcaformat gt mode lt mode gt netmode lt netmode gt lambda lt lambda gt usegui 3 3 1 Example The graphic interface for the h draindir command is shown in figure 3 10 h draindir rparameters 2 normale seleziona il metodo da usare rete fissata formato della mappa grass raster delle elevazioni depittato pit test flan_geotop Sfoglia formato della mappa grass mappa delle direzioni di flusso fis tant flan_geotop Sfoglia formato della mappa grass Sfoglia valore di lambda 1 formato della mappa grass mappa delle direzioni di flusso a flan_geotop Sfoglia formato della mappa grass mappa delle aree totali contribuenti dica test flan_geotop Sfoglia LAD tipo di algoritmo usato LO LTD ee 7 OK 3 Cancel J
46. on of GEOtop 5 1 Format of the Input Files GEOtop requires the input maps to have a particular format called Fluidturtle see the GEOtop Manual With JGrass it is possible to generate the maps directly in this format These input files are ASCII files with a header containing details about the region resolution coordinates and number of points that make up the map Here is an example Created by h pitfiller from the map DTM index 3 1 float array header 10 0 10 0 5110090 0 1635940 0 2 float array novalue 1 9999 0 3 double matrix pit 640 580 The first line is a comment that the program does not read it contains information about the origin of the file In the example the comment states that the map was created with h pitfiller using the map DTM as input The string index 3 specifies the number of blocks of data in the file in this case 3 The first data block has information about the region in question e 10 0 10 0 are the pixel dimensions in metres e 5110090 0 1635940 0 are the coordinates of upper left corner of the map The term float array means that the data are floating points and they are contained in an array which in Fluidturtles jargon means a data set of unspecified length contained between two header is the name of these data while novalue is the name of the second data block The 5 Input Maps for GEOtop second block gives the value assigned
47. on of the Hydrographic Basin with marked outlets the map upon which the threshold will be imposed In the example the map used is the total contributing areas map calculated with h draindir The threshold value is set to 150 pixels the map resolution is 10m Figure 3 18 shows the results of the calculation Figure 3 18 h extractnetwork Map of the hydrographic network obtained by imposing a threshold on the contributing areas The network points are marked in red assigned value of 2 The map represents an area of the Province of Trento It must be noted that in the resulting map numerous groups of hydrographic networks are identified each group corresponds to a small basin as will be seen later 26 3 Data Preprocessing for the Extraction of the Hydrographic Basin 3 5 2 Determination of the Network Using the Contributing Areas and the Slopes The calculation is done by imposing a threshold on the product of two quantities for example the contributing area and the slope The first step is therefore the calculation of the slope map This operation is done with h gradient Gradient The gradient is calculated in each point of the map The command to execute is h gradient From the main menu select HortonMachine gt Basic topographic attributes gt h gradient or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Basic topographic attributes Figure 3 19 sho
48. rd will appear from where the map to display can be selected figure 2 15 JGRASS Java ES Visualizza una mappa vettoriale Visualizza una mappa di punti Visualizza un layer da Postgis amp Cancella le mappe dal display I Rebuild map image at current zoom Figure 2 14 Selecting the toolbar with the d rast command icon The result of the procedure is shown in figure 2 16 11 2 Preliminary Operations Figure 2 15 Displaying a map in JGrass 763 9355 906 0293 1048 1232 1190 217 1332 3108 1474 4047 1616 4985 1758 5924 1900 6863 2042 7802 2184 874 Figure 2 16 The result of the importation process DEM of the Flanginec Basin 12 3 Data Preprocessing for the Extraction of the Hydrographic Basin In order to extract the hydrographic basin of interest some processing of the original digital data of the land area containing the basin is necessary The processing operations include eliminating the pits Pitfiller calculating the drainage directions Flowdirections and Draindir and the extraction of the hydrographic network Extractnetwork 3 1 Pitfiller Pitfiller eliminates possible points of depression thus the drainage directions can be calculated correctly The command to execute is h pitfiller To launch it from the main menu select HortonMachine gt DEM manipulation gt h pitfiller as shown in figure 3 1 The command can also be launched by clicking the
49. re 5 15 The h aspect icon The h aspect command can also be executed from the console command line h aspect quiet verbose version usage pit lt pit gt pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt aspect lt aspect gt outmapset lt outmapset gt outputformat lt outputformat gt useguil Example The dialog box requiring the names of the input and output maps is shown ion figure 5 16 The resulting output map is shown in figure 5 17 99 5 Input Maps for GEOtop parameters formato della mappa grass raster delle elevazioni depittato pit test m flan_geotop formato della mappa grass mappa delle esposizioni aspect test m flan_geotop Figure 5 16 h aspect Dialog box where the names of the input and output maps are specified Figure 5 17 h aspect The aspect map The Flanginec Basin 54 5 Input Maps for GEOtop 5 2 4 Dist2Outlets GEOtop then needs the map showing the distance of every pixel from the outlet following the drainage directions in order to calculate the amplitude function JGrass gives the choice to calculate the distance either in metres or in number of pixels GEOtop needs the distance expressed as number of pixels The command to execute is h D20 From the main menu select HortonMachine gt Network related measures gt h D20 or else click the corresponding icon from the toolbar that app
50. s to calculate the drainage directions causes a deviation of the flow with respect to the real path taken by the water on its descent downstream Orlandini et al 2003 The Draindir command recalculates the flow path with a correction that minimizes the deviation The program also calculates the contributing areas TCA or Total Contributing Area which rep resent the projection onto a horizontal plane of the areas that contribute to a point of the basin The calculation of this quantity is done by following the drainage directions from every point of the basin and then cumulating the area along the paths determined by the drainage directions For further details about the method used please refer to The Horton Machine 2 and the article by Orlandini et al 2008 15 The command to execute is h draindir from the main menu select HortonMachine gt Basic topographic attributes gt h draindir or else click the corresponding icon from the toolbar that appears by checking HortonMachine gt Basic topographic attributes The toolbar with the h draindir icon is shown in figure 3 9 Figure 3 9 The h draindir icon The command gives you a choice of the calculation method to use and allows you to fix the hydrographic network if this is known For details regarding the calculation methods LAD and LTD and the parameters to be input refer to The Horton Machine 2 The h draindir command can also be executed from the console command li
51. scont 5 44 Salsa ds a a a eB A 14 h pitfiller Dialog box where the names of the input and output maps are specified 15 h pitfiller Depitted elevation map The Flanginec Basin LL 15 The D HOWwdiFeGtions ICON s sa A Gd a elia 16 h flowdirections Dialog box where the names of the input and output maps are specified 17 h flowdirections Drainage directions map The Flanginec Basin 17 FRe dfalNdif CoN is o ae dee LETO LE o da 18 h draindir Dialog box where the names of the input and output maps are specified 19 h draindir Map of the corrected drainage directions The Flanginec Basin 20 111 LIST OF FIGURES 3 12 3 13 3 14 3 15 3 16 3 17 3 18 3 19 3 20 3 21 3 22 3 23 3 24 3 25 3 26 3 27 3 28 3 29 3 30 3 31 3 32 3 33 h draindir Total contributing areas map based on the corrected drainage directions The unit of measurement is pixels The Flanginec Basin o 21 The Mem arkOutlets 160M 3 su sand me a o we He Se 22 h markoutlets Dialog box where the names of the input and output maps are specified 23 h markoutlets Corrected drainage directions map with the region outlets marked TATOO RZ A ds a Be e e ee e 23 The Neextractnelwork icon mari da id Se wm Be we ee SH es 24 h extractnetwork Dialog box where the names of the input and output maps are Sii di O LU ee es ee E A Oe ee 25 h extractnetwork Map of the hydrographic network obtained by imposing a
52. the program will automatically assign the value of 9999 0 e usegui allows you to view the dialog box of the command you must write r in ascii usegui this string must not be included for the execution of the command to execute r in ascti as in the example in paragraph 2 3 1 it is sufficient to write r in ascii ascii Users erica Desktop eclipse workspace jgrass1 DTM map mapset DTM flan_ geotop For further information on the use of the console please refer to the JGrass User Manual 1 2 4 Setting Up the Active Working Region Before viewing the imported map it is necessary to set up the active working region This procedure allows you to assign the coordinates and resolution of the imported map to the display screen The command to execute is g region from the main menu select Gis gt Region Tools gt Region Manager as shown in figure 2 11 A dialog box will appear where the information about to the region is input an example is shown in figure 2 12 2 Preliminary Operations e608 JGRASS Java GRASS Build 20060131085 File Visualizza Gis Raster Vettoriali Extra HortonMachine Aiuto AN Strumenti di importazione esportazione Q Q e Q Strumenti della regione gt Gestione della regione Strumenti di importazione esportazione x Proprief Gestione della regione attiva Figure 2 11 The g region con The g region command can be executed from the console com
53. threshold on the contributing areas The network points are marked in red assigned value of 2 The map represents an area of the Province of Trento 4 26 The MOTAClIent COM 52 5 oa 6 S 8 AA AA AAA 21 h gradient Dialog box where the names of the input and output maps are specified 28 h gradient Gradient map The Flanginec Basin o o 28 h extractnetwork Dialog box where the names of the input and output maps are SDOCIICO amp opel MR e Se 29 h extractnetwork Map of the hydrographic network obtained by imposing a threshold on the product of the contributing areas and the gradient The Flanginec Basin 30 TO M CUTVA LUTO ICON Pai aL lai 31 h curvatures Dialog box where the names of the input and output maps are specified 32 h curvatures Map of the tangent curvature left profile curvature right and planar curvature bottom of the Flanginec Basi n o o 32 Subdivision of the pixels by curvature oi AE e OS ES 34 A AE i e 34 h tc Dialog box where the names of the input and output maps are specified 35 h tc Map of the topological classes with classification according to 9 categories 36 h tc Map of the topological classes reclassified according to 3 categories The con cave sites are marked in yellow the convex sites are marked in red and the planar DIOS CPCI OVC siii heel ene do ei 36 h extractnetwork Dialog box where the names of the input and output maps are
54. verbose version usage pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt prof_curv lt prof_curv gt prof_curumapset lt prof_curumapset gt prof_curvformat lt prof_curvformat gt plan_curv lt plan_curv gt plan_curumapset lt plan_curumapset gt plan_curv format lt plan_curuformat gt tang_curv lt tang_curv gt tang_curumapset lt tang_ curumapset gt tang_curvformat lt tang_curuformat gt usegui Figure 3 24 The h curvatures icon Example The curvatures are to be calculated The required input is the depitted elevation map calculated with h pitfiller In figure 3 25 the dialog box where the names of the input map and output maps are specified the resulting output maps are shown in figure 3 26 31 3 Data Preprocessing for the Extraction of the Hydrographic Basin h curvatures formato della mappa grass raster delle elevazioni depittato pit test flan_geotop formato della mappa grass mappa delle curvature eZ longitudinali prof test flan_geotop formato della mappa grass mappa delle curvature I planari plan test flan_geotop formato della mappa grass mappa delle curvature tangenziali tang test flan_geotop Figure 3 26 h curvatures Map of the tangent curvature left profile curvature right and planar curvature bottom of the Flanginec Basin 32 3 Data Preprocessing for the Extraction of the Hydrographic Basi
55. ws the toolbar with the h gradient icon Figure 3 19 The h gradient icon The h gradient command can also be executed from the console command line h gradient quiet verbose version usage pit lt pit gt pitmapset lt pitmapset gt pitformat lt pitformat gt gradient lt gradient gt gradientmapset lt gradientmapset gt gradientputformat lt gradientputformat gt usegui Example The first thing to do is calculate the gradient map to execute the command click the icon shown in figure 3 19 The depitted elevation map calculated with h pitfiller is required as input The graphic interface of the h gradient command where the names of the input and output maps are given is shown in figure 3 20 Figure 3 21 shows the resulting output map 27 3 Data Preprocessing for the Extraction of the Hydrographic Basin parameters formato della mappa grass raster delle elevazioni depittato pittest 1 fiang eotop formato della mappa grass mapa del gradiente flan geotop Figure 3 20 h gradient Dialog box where the names of the input and output maps are specified The result of the processing operation is shown in figure 3 21 0 0 0 46440285 0 9288057 1 3932085 18576114 23220143 2 786417 3 25082 3 7152228 4 0248265 4 489228 Figure 3 21 h gradient Gradient map The Flanginec Basin 28 3 Data Preprocessing for the Extraction of the Hydrographic Basin
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