Floodplain Mapping & Hydraulic Analysis with HEC
Contents
1. River Reach River Station Fretn n K nel n e nea a 1 Rivert Reach 4600 3534 ri 2 Rivert Reach 4340 715 ri 3 Rivert Reach d2z0 529 i 4 Rivert Reach 4116 786 ri 5 Rert Reach 4091 636 ri 6 Rivert Reach 3906 540 ri T Riverl Reach 3691 426 i 0 Rivert Reach 3200 91 i 9 Rivert Reach 3066 478 ri 10 i Rer Reach 2059 056 z E E OK Cancel Levees Levees are linear features that contain the flow of water inside the floodplain Some channel scenarios may require levees to be defined in order to maintain the true flowpath of the water Usually levees represent man made features in tended to constraint the floodplain but can also represent other type of high ground such as roadway embankments or ridges in the natural topography of the landscape that blocks the flow until they are overtopped Levees are only required if the high ground prevents the stream from being hydraulically connected to the terrain at the other side If the terrain at the other side is hydraulically connected to the stream upstream of the high ground a levee should not be placed on the cross section In the example presented in this tutorial the railroad track embankment which runs somewhat parallel to the creek acts as a levee The way the cross sections have been drawn in this tutorial the most upstream cross sections intersect the railroad embankment and require levees to be defined in HEC RAS Your cross sections may or m2. AO ear Help Cancel Three new TINs t 100 year t 50 year and t 10 year will be added to your map On the HEC GeoRAS toolbar select RAS Mapping Inundation Mapping Floodplain Delineation GRID Intersection from the menu The following window will appear Again select all three water surface profiles and then select OK It may take a few minutes to finish depending on your computer Floodplain Delineation x Select water surface profile Help Cancel After this process is finished several new feature classes will be added to your data frame The feature classes named b 10 year b 50 Year and b 100 Year are the floodplain boundary feature classes The grids d 10 Year d 50 Year and d 100 Year represent the water inundation depths within the delineated floodplains You should examine your map with the following points in mind and if something is not right you may have to redo part of your analysis e Does the cross section cut lines fully encompass the floodplain polygons If not you may need to extend your cross section cut lines e Does the placement of your levees make sense with the extents of the floodplains you have mapped The following maps show some final results for this hydraulic analysis and floodplain delineation using HEC GeoRAS Yours should look similar but probably not identical Note that in the following figure the floodplain is wider than the cross sections in some places u
3. Zachry Department of Civil Engineering HEC R AS Finished Computations IOl x Steady Flow Simulation River River RS 4653 894 Reach Reach Node Type Cross Section Profile 100 Year Simulation 3 4 Computation Messages Steady Flow Simulation Version 3 1 2 April 2004 Finished Steady Flow Simulation Total Computation Time 0 min 0 45 sec e Exporting Data Back to GIS Once our hydraulic model is run successfully we are ready to export the high water surface elevations for the three flow scenarios back to GIS From the main HEC RAS window select File Export GIS Data The following window will appear Save this file to your RAS folder in your working directory and let it be saved with the default name RASexport Choose the same options as shown in this picture and then select Export Data Export File EST utora RAS Creek AAS export sdf Browse Results Export Options M Export Water Surfaces Select Profiles to Export Profiles to Export Velocity Distribution Information where available Use version 2 2 export format Geometry Data Export Options IM Export River Stream Centerlines Cross Section Surlace Lines Additional Properties Export User Defined Cross Sections Reach Lengths all 85 s except Interpolated 15 s Bank Stations Export Interpolated Cross Sections IW Levees f Entire Cross Section Ineffective Areas Channel only Blocked
4. www hec usace army mil software hec ras hec georas_downloads html e HEC RAS River Analysis System User s Manual CPD 68 Hydrologic Engineering Center U S Army Corps of Engineers Davis California November 2002 http www hec usace army mil software hec ras hecras document html Sarah Meyer is a Civil Engineering Graduate of Texas A amp M University She developed this exercise in partial fulfillment of the requirements of the CVEN658 Civil Engineering Applications of GIS class taught the Fall 2006 Francisco Olivera folivera civil tamu edu is an Assistant Professor of Civil Engineering at Texas A amp M University He teaches graduate and undergraduate courses and conducts research on the use of GIS in water resources engineering Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page l of 42 Texas A amp M University Zachry Department of Civil Engineering e HEC RAS River Analysis System Hydraulic Reference Manual CPD 69 Hydrologic Engineering Center U S Army Corps of Engineers Davis California November 2002 http www hec usace army mul software hec ras hecras document html The HEC RAS manuals are useful to answer any questions you may have about the hydraulic analysis portion of this tutorial If you want to apply the procedures from this tutorial to a new location or you need to trouble shoot a specific problem all three manuals will be a valuable reference to
5. 44 Downstream Invert Elev 659 8 _ Entrance Loss Coeff 0 3 o identical barrels 2 Exit Loss Coeff Stations Manning s n for Top Manning s n for Bottom Depth to use Bottom n Depth Blocked z OK Cancel Help Select culvert to edit After clicking OK in the Culvert Data Editor window the Bridge Culvert Data window should look similar to the picture below Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 30 of 42 Texas A amp M University Zachry Department of Civil Engineering Bridge Culvert Data Geometry3 File View Options Help River Rivet ss Apply Data 10 Reach Recht gt River Sta naa y a t Description He Bounding XS s 4229529 4116 788 Distance between 111 74 ff Deck RS 4181 474Upstream Culvert 685 Ground 675 Levee Ss amp 5 670 Bank Sta iG 665 685 RS 4161 474Downstream Culvert 675 5 670 3 a 665 0 100 200 300 400 500 600 Station ft iv Bridge amp Culvert Data Downstream Bridge This section describes how to enter the data to model the bridge and culvert for the second bridge crossing The following site photo shows this bridge crossing 7 F ms ee E r 5 L 4 7 _ a r Page eee cia Th S T i 7 Fy Sine a ee r i A a Ri ae Ss a E cee lh ge A Na aS OR ace etree ar at M Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeo
6. All The following pop up window will be displayed Use the drop down menu to select the correct layer name for each item on the list The first 5 items on the list will be used to populate the empty fields in the attribute table of the XSCutLines feature class The last item 1 e XS Cut Lines Profiles is the name of a new feature class that will be created The 2D feature class XSCutLines will be intersected with the TIN to create a feature class with 3D cross section cut lines Accept the default name for this feature class XSCutLines3D EN All Cross Section Tools Ei Stream Centerline Bwe Bank Lines Baks Flow Path Centerlines Flowpaths evo Cut Lines XSCutlines Terrain tin_ ft 235 Cut Lines Profiles xs CutLines30 Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 15 of 42 Texas A amp M University Zachry Department of Civil Engineering Select OK on the All Cross Section Tools window and the following message will appear Select OK again All Cross Section Tools x Batch process on Cross section tools completed successfully Open the attribute table of the new feature class XSCutLines3D and examine of the populated fields viii Bridges Culverts Bridges and culverts are treated similarly to creating the cross section layer Begin an editing session and then select Create New Feature for the Task and Bridges as the Target layer in the Editor toolbar Di
7. Culverts Bridges ss stream Centerline Rives Terrain lint Bridges Lulverts Profiles Bridges3D Select OK on the All Bridge Culverts Tools window and the following message will appear All Bridge Culverts Tools X Batch process on bridgefculverts tools completed successfully x Optional RAS Layers For the purpose of this tutorial we are finished digitizing RAS layers In the table of contents window in ArcMap you will notice that there are several empty feature classes SAConnections StorageAreas IneffAreas BlockedObs LandUse that were created at the beginning but we did not populate them It is fine to not use all of the optional RAS layers but in the future you may come across a project where their application is beneficial to you The HEC GeoRAS User s Manual describes these additional RAS layers their use and instructions for applying them to a scenario 4 Exporting GIS Data to HEC RAS a Selecting Data for Export From the HEC GeoRAS toolbar select RAS Geometry Layer Setup from the menu The Layer Setup window with four tabs Required Surface Required Layers Optional Layers and Optional Tables will appear These tabs are shown in the next four figures and include the preferences you should choose for this tutorial The purpose of the Layer Setup menu is to define which layers will be exported to HEC RAS In this example many of the menu items will show a Null value because we did not use all of
8. HECGeoRAS after FO doc Page 12 of 42 Texas A amp M University Zachry Department of Civil Engineering Assign LineType to Flowpath Featur x Assign LineType to Flowpath Feature Ed ee mem toa eine OF Help Cancel OF Help Cancel vi XS Cut Lines Cross sectional cut lines are used to define cross sections along the channel network by using vertical planes i e the XS cut lines to cut the terrain TIN There are a few important rules to keep in mind when drawing cross section cut lines Cut lines should be perpendicular to the direction of flow You can use both the river centerline and the flowpath lines to assist you in this task You can dog leg cut lines 1f need be to keep them perpendicular to the direction of flow Cut lines should be drawn directionally from left to right bank Cut lines should extend far enough on either side of the channel to encompass the entire portion of the floodplain you want to model They should end at the same elevation at both ends e Cut lines should not intersect each other Cut lines should be spaced close enough to account for notable changes in the hydraulics or geometry of the stream such as changes in discharge slope cross section shape roughness or presence of hydraulic structures bridges levees weirs Each bridge intersection will require 4 cut lines 2 upstream of the bridge and 2 downstream of the bridge See the following figure for an i
9. down menu Select Create New Feature in the task window of the toolbar and River name of stream centerline for the target feature class as seen in the figure below Editor ae x Editor b Task create Mew Feature Target River Ea E Select the sketch tool E from the Editor toolbar to digitize the stream centerline in the downstream direction Left clicking the mouse will drop a vertex point for the an line and double clicking the left mouse button will finish the line You can pan and zoom in and out aa without interrupting your line drawing After panning or zooming you will have to select the sketch tool again to resume drawing your line Selecting the undo tool lt will remove the last point you placed and can be very useful for erasing mistakes When your centerline is complete from the Editor toolbar select Editor Save Edits and then Editor Stop Editing to end your edit session Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 6 of 42 Texas A amp M University Zachry Department of Civil Engineering Digitizing the Stream Centerline The following picture shows a close up view of the stream Begin digitizing your stream centerline at the downstream end of the railroad crossing and follow through to the outlet into the Guadalupe River o Ra Bridge 1 Railroad Crossing Bridge 2 The next picture shows a close up view of digitizing the str
10. exe has been included in the HECSoftware folder a Creating a HEC RAS Project Begin by opening the HEC RAS program The main HEC RAS interface window will appear on your screen and looks like the following picture ii HEC RAS 3 1 3 File Edit Run View Options Help ES Esd us army corps orenga gail Project Plan Geometry Steady Flow Unsteady Flow E O i E US Customary Units 1 Select File New Project from the main HEC RAS interface A window will appear which looks like the next picture Browse to your working directory and create a new folder called RAS in it to store the HEC RAS files separately Enter a title and file name for the project they can have the same name Select OK Select OK again on the menu that pops up Note that by default the units are US Customary Units 1 e English units Do not change them since these units match the ones we were working with in GIS Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 20 of 42 Texas A amp M University Zachry Department of Civil Engineering Sew Project Title File Hame Directories Creek Creek pr EAT utora AAS ar E Tutorial OF Cancel Help Create Directory EP f Metudentrd1 Skbrumbelow2 E et dive and path then enter a new project title and file name b Importing RAS Layers from GIS Open the Geometric Data window by selecting from the mai
11. for the 2003 FEMA mapping of the Guadalupe River For the purpose of this tutorial these data is given to you Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 34 of 42 Texas A amp M University Zachry Department of Civil Engineering Enter Edit Number of Profiles 2000 mas 3 Reach Boundary Conditions Apply Data Locations of Flow Data Changes River Riveri Reach Reach 7 River Sta 2035 310 Add 4 Flow Change Location Flow Change Location Profile Names and Flow Rates BO year Feach 4659 894 3363 57 5196 00 5839 90 Tawasa Sere errr erry Reach 2039 310 721 27 1070 65 1169 57 Edit Steady flow data for the profiles cfs Now select the Reach Boundary Conditions button Since a subcritical flow analysis requires only a downstream boundary condition click on the cell below the word Downstream Next click the Normal Depth button and enter 0 009 in the blank space as seen in the next picture This slope value is approximately the average slope of the entire channel Click on OK Enter the downstream slope for narmal depth computation tor reach leach for all profiles o 003 LE Cancel The Steady Flow Boundary Conditions window should now look like the following picture Click on OK Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 35 of 42 Texas A amp M University Zachry Department of Ci
12. section points filter which will allow us to delete excess and duplicate points In the Geometric Data window select Tools Cross Section Points Filter Once the Cross Section Points Filter window opens select the Multiple Locations tab and then the Minimize Area Change tab In the Da River option select All Rivers and press the arrow LJ to slect them Just for practice we will filter our cross section to 250 points but most of the cross sections already fall below this value Enter 250 for the number of points to filter down to and press the Filter Points on Selected XS button to complete this task The following picture shows all of the appropriate options selected Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 23 of 42 Texas A amp M University Zachry Department of Civil Engineering Cross Section Point Filter f Single Location Multiple Locations Selected Locations 16 selected River All Rivers poses 422 345 4169 684 3989 716 3620 280 3317 565 2926 489 2992 09 2290 983 2181 003 2039 310 1355 543 1780 921 1298 701 013 6921 500 4468 2er 0929 Mear and Colinear Fiter Minimize Area Change Number of points to trim cross section down to 250 Filter Points on Selected 5 OK Cancel E nter the target for paint reduction procedure A new window will appear showing the cross sections that had more than 250 points or duplica
13. step and will be stored collectively in a GeoDatabase which HEC GeoRAS creates automatically By default this GeoDatabase will be saved in the same location as the ArcMap project with which you are working and will be given the same name To create the RAS layers on the HEC GeoRAS toolbar select RAS Geometry Create RAS Layers All as shown in the following figure Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 4 of 42 Texas A amp M University Zachry Department of Civil Engineering HEC GeoRAS x RAS Geometry RAS Mapping rd ant i ae oe d Apwtilities Help Stream Centerline Layer Setup Bank Lines Stream Centerline Attributes p Hew Pein Canola ao Cut Lines s5 Cut Line Attributes b E Manning s n Values Ineffective Flow Areas Levees b Blocked Obstructions Ineffective Flow Areas b Landuse Areas Blocked Obstructions p Levee Alignment Bridges Culverts b Levee Points Inline Structures Inline Structures Lateral Structures H Lateral Structures Storage Areas b TETERE Firetels Storage 4rea Connections p storage Area Connections Aull Extract GIS data Then the following pop up window will appear For this exercise we will accept all of the default RAS layer names by choosing OK on the Create All Layers window Create All Layers X Stream Centerline River Bank Lines Banks Flow Path Centerlines Flowpaths x5 Cut Lines fMSCutlines Bridges Culve
14. the optional RAS layers in this tutorial Once you have made all your selections in the Layer Setup tabs select OK Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 17 of 42 Texas A amp M University Zachry Department of Civil Engineering Layer Setup Terrain Type f TIN i Grid Select Terrain tin ort Multiple DTM Tiles Layer sul f Single T Apply HEC GeoRAS Symbology OF Help Cancel Layer Setup Stream Centerline Fiver Ao Cut Lines XSCutLines s5 Cut Lines Profiles X CutLines30 Apply HEC GeofAS Symbology OF Help Cancel Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 18 of 42 Texas A amp M University Zachry Department of Civil Engineering on Layer Setup x Required Surface Required Layers Optional Layers Optional Tables Bank Lines Bans tts Stream Profiles Nui Flow Path Centerlines Fiowpaths Storage Areas Nui Land Use Nui Storage Points Nui Levee Alignment Nui Levees Profiles Nui Ineffective Flow Areas Nui Levee Points Null v Blocked Obstructions Nui Bridges Culverts Bridges i assis Bridges Culverts Profiles Bridges3s0 xl Inline Structures Nu o Inline Structures Profiles Nui Lateral Structures Nui ts Lateral Structures Nui SA Connections Nui SA Connections Profiles Nui Apply HEC GeoRAS Symbology LE O Manning JNul Levee Posi
15. you The region of study for this exercise is a small tributary to the Guadalupe River named Cypress Rapids Creek which is located in New Braunfels TX This creek is approximately one mile in length drains about 2 3 square miles and has two bridge crossings within the study reach The required data for this exercise is stored in the folder TutorialDataGeoRAS Maintaining the folder structure copy the folder to your hard drive To be safe make sure your folder name and path do not contain blank spaces You might need to change the folder and file properties to remove the Read Only attribute 2 Downloading and activating the HEC GeoRAS 4 1 1 extension If you already have HEC GeoRAS 4 1 1 installed in your computer you may skip this section and continue at 3 Using ArcMap to create RAS geospatial layers for a stream a Make sure that any old versions of HEC GeoRAS APFramework MSXML or XML Data Exchange Tools are properly uninstalled Remove these programs through the Windows Control Panel using the Add Remove Programs option If you do not find APFramework in the Add or Remove Programs list run the program Unwise exe located in C Program Files ESRI WaterUtils APFrameworkX folder to uninstall it Note that the location of Unwise exe might change depending on where ArcGIS was installed in your computer Additionally navigate to C Program Files ESRI WaterUtils the default storage location of APFramework and XML Data Exchange Tools
16. Obstructions Export Data Cancel Help Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 28S HECGeoRAS after FO doc Page 37 of 42 Texas A amp M University Zachry Department of Civil Engineering If your data were successfully exported the following message appears SS Eti lt a i x Export file Fy TuborialiRas Creek RASexport sdf created 6 Importing Data from HEC RAS Return to your project in ArcMap and follow these directions to import the data from your HEC RAS hydraulic model On the HEC GeoRAS toolbar click on the Import RAS SDF File button The following window will appear Use the browser to locate the RAS Output File you just created in HEC RAS probably stored in your RAS folder in your working directory Select OK and this action will convert the SDF file to and XML file which GIS can read Convert RAS Output ASCII File to ML RAS Output File F TutorialsRAS Creek RASexport sf i ML File FST utoriah RAS Creek RAS export sml OF Help Cancel If you are successful in file conversion you will receive the following message RAS Output Conversion x RAS ASCII output successfully converted to XML Next from the HEC GeoRAS toolbar select RAS Mapping Layer Setup from the menu The following dialog box will appear Make the same selections as shown in the picture You will have to give your analysis a name select the TIN option and b
17. RAS after FO doc Page 31 of 42 Texas A amp M University Zachry Department of Civil Engineering Follow the same steps you followed for the first bridge The following figures show you the data that has to be entered Recall that some of the data depends on your cross sections aaa Culvert Data Editor z _ Rename 4 t Crouer x es Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 32 of 42 Texas A amp M University Zachry Department of Civil Engineering Bridge Culvert Data Geometry3 O Xx File View Options Help iver ve Apply Data 1 Reach Reach v River Sta 1954 266 Description Bounding xS s 1982 681 1926 639 Distance between 56 04 f Le E 665 RS 1954 266Upstream Culvert E 660 Ground o c 655 Bank Sta 650 TT 645 640 0 100 200 300 400 500 600 700 665 RS 1954 266Downstream Culvert 660 c 655 2 w a 650 mr 645 640 0 100 200 300 400 500 600 700 Station ft Select the river for Bridge Culvert Editing When you are finished entering data make sure you SAVE the geometry data file or all of this will disappear d Running the HEC RAS Model i Enter Steady Flow Data From the main HEC RAS window select the Edit Enter Steady Flow Data button El The Steady Flow Data Editor will open In this editor enter 3 in the op
18. Texas A amp M University Zachry Department of Civil Engineering Floodplain Mapping amp Hydraulic Analysis with HEC GeoRAS 4 1 1 and ArcGIS 9 1 Prepared by Sarah Meyer and Francisco Olivera Ph D P E May 2007 Contents Goals of Exercise amp Additional Resources Downloading amp Activating the HEC GeoRAS 4 1 1 Extension Using ArcMap to Create RAS Geospatial Layers for a Stream Exporting GIS Data to HEC RAS Hydraulic Analysis in HEC RAS Importing Data from HEC RAS Mapping Floodplains Using GIS ee ee 1 Goal of the exercise additional resources and study area The purpose of this exercise is to familiarize the user with the floodplain mapping capabilities of the extension HEC GeoRAS developed by the Hydrologic Engineering Center HEC of the U S Corps of Engineers HEC GeoRAS 4 1 1 requires ArcGIS 9 1 with the 3D Analyst and the Spatial Analyst extensions This tutorial was successfully completed using HEC RAS 3 1 3 The HEC GeoRAS extension has many optional capabilities that will not be explored or do not apply to the stream used in this tutorial Three manuals prepared by the Hydrologic Engineering Center HEC were used extensively in the preparation of this tutorial The references for these manuals are listed below e HEC GeoRAS GIS Tools for Support of HEC RAS Using ArcGIS User s Manual CPD 83 Hydrologic Engineering Center U S Army Corps of Engineers Davis California September 2005 http
19. a r Typical flow transition Piz pattem 2 F ri E x oe ie xpansion Reach L T p x d Idealized flow transition pattern for 1 dimensional i modeling n EM Ne Ul ee USACE HEC RAS User s Manual 2002 To draw cut lines star an editing session and select Create New Feature from the Task menu and XSCutLines from the Target menu Draw all the cut lines do not forget to draw the bridge cross sections and save your edits As you are drawing cut lines you can preview the cross section using the XS Plot tool After pressing the XS Plot tool left click on the cross section of interest a plot will appear in a new window This feature will help you ensure you are drawing your cross sections long enough to capture the entire floodplain After drawing the cut lines they should look similar to the following figure Note the bridge location in the upper right corner Also note that even though two of the cross sections might look like intersecting they are just very close to each other but do not intersect Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 14 of 42 Texas A amp M University Zachry Department of Civil Engineering vii Attributing Cross Section Cut Lines amp Creating a 3D Feature Class Now we will populate the attribute table of the XSCutLines feature class we just digitized From the HEC Geo RAS toolbar select RAS Geometry XS Cut Line Attributes
20. and delete the folder b Navigate to http www hec usace army mil software hec ras hec georas_downloads html and click on Primary Download Site under the heading HEC GeoRAS 4 1 1 for ArcGIS 9 1 Select Save on the pop up menu navigate to the folder where you would like to store the HEC GeoRAS4 1 1 exe file and click Save For your convenience the file HEC GeoRAS4 1 1 exe has been included in the folder HECSoftware so you do not have to access the Internet and download it if you prefer not to do so c Use Windows Explorer to navigate to the folder where you just saved the HEC GeoRAS4 1 1 exe file Unzip it and save it in the same folder Next open the newly unzipped folder HEC GeoRAS 4 1 1 and open the text file Installation Instructions 4 1 1 txt The instructions in this text file will guide you through the remainder of the file installation process Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 2 of 42 Texas A amp M University Zachry Department of Civil Engineering d You are now ready to start working with HEC GeoRAS Open ArcMap HEC GeoRAS will be loaded as a toolbar in ArcMap HEC GeoRAS x RAS Geometry RAS Mapping rad eee IL dl Se se ot fF Apwtilities Help Y If the HEC GeoRAS toolbar is not loaded in ArcMap select Tools Customize from the main interface menu click on the Toolbars tab and place a checkmark in the box corresponding to HEC GeoRAS While in t
21. ation as is shown in the next picture then select OK Do not just copy these values they depend on the location of your cross sections The Distance to Upstrm XS is the same one you entered previously that is the distance between the bridge and the next upstream cross section The Centerline Stations represent the centerlines of the two side by side box culverts Since your bridge cut line may be of a different length or in a different place than mine you must enter these values yourself Find what looks like the center station of your upstream channel cross section subtract 5 feet from this value and enter this value as the Centerline Station for the upstream section of culvert 1 If you add 10 feet to the centerline station of the upstream culvert 1 you get the correct placement of the centerline station of upstream culvert 2 Follow the same process for the downstream culvert alignment based upon the downstream channel centerline and make points and 2 ten feet apart again The Upstream Invert Elev and Downstream Invert Elev will also depend on the specific location where you defined your cross sections a Culvert Data Editor dd Copy Delete Culvert ID Solution Criteria Highest US EG ali Rename aa mG Shape Box x Span fe Rise fe _ Chart a flared wingwalls v _ Scale fi Wingwall flared 30 to 75 deg v Distance to Upstrm XS 38 4 Upstream Invert Elev 660 2 Culvert Length
22. ay not cross the railroad tracks so you will have to inspect your own sections to make sure In the data provided Railroad shp depicts the railroad embankment You may want to add it to your map to see if your cross sections extend across it You can also look for topographical features in the landscape intersected by your cross sections for potential levee locations Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 25 of 42 Texas A amp M University Zachry Department of Civil Engineering To place levees in HEC RAS follow these directions Levees will be placed on the roadway embankment for the most upstream cross sections Only one cross section is presented in this example to show you how to add levees but you should add levees for all the cross sections to which levees apply Cross section In the Geometric Data window select the Cross Section button This will bring up a window displaying your cross sections one at a time Using the arrow buttons sit browse to one of your cross sections that intersects the railroad embankment this tutorial will use the most upstream cross section for this example On the Cross Section Data window select Options Levees and the window in the next picture will appear xs Levee Data i Station Elevation Enter the station and elevation of the levee in this window You can add two levees in a cross section one on the left ban
23. eam The stream centerline will follow the path of lowest elevation so care must be taken to find the lowest elevations and then connect them with the streamline You can find individual elevation points on the TIN by selecting the Identity tool and then clicking on the TIN layer in the map A pop up box will appear listing the elevation at that point Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 7 of 42 Texas A amp M University Zachry Department of Civil Engineering Identify Results Layers lt T op most laper El tin 2Ft Location 2253029 269202 13818003 183385 H 638 022 Elevation Slope Aspect Face Tag Value Node Tag Value The next picture shows a close up view of one of the bridge crossings When digitizing the stream follow from the centerline of the upstream side of the bridge to the centerline of the downstream side of the bridge passing through the center of the bridge Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 8 of 42 Texas A amp M University Zachry Department of Civil Engineering il River Reach Name Each river and each reach within each river must have a name which uniquely identifies it The River Reach ID tool o on the HEC GeoRAS toolbar will allow you to number the reaches Click on the River Reach ID tool Use the cursor to select the first river reach in this tutorial we have
24. ength for Stations i X River length and station distance successfully calculated iv Bank Lines Layer The purpose of creating this layer is to distinguish between the main channel of the river and the floodplains overbanks of the river The bank lines will be created in similar fashion as the river centerline and also starting from upstream On the Edit toolbar select Editor Start Editing Make sure the task window of the Edit toolbar says Create New Feature and that your target is now set to Banks Select the sketch tool from the Editor toolbar and begin digitizing either the right or left bank line in the downstream direction Left clicking the mouse will drop Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 10 of 42 Texas A amp M University Zachry Department of Civil Engineering a vertex point for the line and double clicking the left mouse button will finish the line You are allowed to pan Ss and zoom in and out aa without interrupting your line drawing After panning or zooming you will have to select the sketch tool again to resume drawing your line Selecting the undo tool will remove the last point you placed and can be very useful for erasing mistakes When the bank line is complete from the Editor toolbar select Editor Save Edits and then Editor Stop Editing to end your edit session Digitizing the Bank Lines Contours lines can help guide you digitize
25. gitize lines tracing each bridge culvert crossing for the stream Bridges culverts follow the same directional rules as the cross section layer Remember to draw them from left overbank to right overbank You can use the TIN the contours layer or the aerial photo provided in the data folder to locate each bridge and draw a line along the centerline of the bridge without intersecting the cross sections Extend your line beyond the ends of the bridge so that you are sure to capture the topography of the section Once finished save edits and end your edit session ix Attributing Bridges Culverts amp Creating a 3D Feature Class From the HEC GeoRAS toolbar select RAS Geometry Bridges Culverts All The following window will pop up menu Use the drop down menu to select the correct layer name for each item on the list The first 3 items on the list will populate the empty fields in the attribute table of the Bridges Culverts feature class The last item 1 e Bridges Culverts Profiles will be the name of a new feature class that will be created The 2D feature class Bridges will be intersected with the TIN to create a feature class of the bridges in 3D In the window below the default name for this feature class Bridges3D is used Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 16 of 42 Texas A amp M University Zachry Department of Civil Engineering All Bridge Culverts Tools X Bridges
26. his menu you may also want to activate the Editor toolbar as it will be needed later Toolbars Commands Options Toolbars Editor Cl Effects O Flood Information Tool Rename CI GPS O Geometric Network Editing Delete Cl Georeferencing Heset C Geostatistical Analyst You will also need to activate both the Spatial Analyst and 3D Analyst extensions for the HEC GeoRAS toolbar to properly work In ArcMap select Tools Extensions from the main interface menu Place a checkmark in the box corresponding to the 3D Analyst and Spatial Analyst extensions Ifthe 3D Analyst and Spatial Analyst toolbars are not loaded select Tools Customize and click on the Toolbars tab as you did before and check the 3D Analyst and Spatial Analyst boxes You are now ready to work with HEC GeoRAS 3 Using ArcMap to Create RAS Geospatial Layers for a Stream a Save your empty ArcMap map in your working directory In this example the map is named RASLayers mxd b The main data input for creating floodplains for a river is a digital terrain model DTM For this exercise you have been provided a triangulated irregular network TIN of the creek study area This TIN was created from a DEM with cell size of 2 feet which makes it appropriate for use in hydraulic analyses and floodplain modeling Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 3 of 42 Texas A amp M University Zach
27. ill describe how to enter the data to model the first bridge crossing The following site photo shows the upstream bridge Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 27 of 42 Texas A amp M University Zachry Department of Civil Engineering BrdgCulu In the Geometric Data window select the Bridge Culvert button will bring up the Bridge Culvert Data editor which Bridge Culvert Data Geometry3 o File View Options Help River jaiNcl Apply Data Reach Peach River Sta 4181 474 al t Description Bounding XS s 4228 529 4116 788 Distance between 111 74 t Reade RS 4181 474Upstream Bridge ke 680 675 Ground E 670 Levee 665 660 Elevation ft a Bank Sta 685 RS 4181 474Downstream Bridge 680 675 670 665 660 Elevation ft 100 200 300 400 500 600 Station ft Select the river for Bridge Culvert Editing options in River Sta select the Deck Roadway button which will bring up Deck Roadway Data editor Enter the Width of the bridge parallel to the flow i e 44 ft and the Distance between the upstream side of the bridge deck and the cross section immediately upstream of the bridge 1 e see figure below and click OK Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 28 of 42 Texas A amp M Unive
28. k and one on the right bank or just one levee Note that you need levees only in the cross sections that have more than one Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 26 of 42 Texas A amp M University Zachry Department of Civil Engineering channel A simple way to locate the levee points is to click on them using the arrow pointer and reading the coordinates in the lower right corner of the display area Once you entered the levee data select OK Next select Apply Data in the Cross Section Data window for the data to be added to the cross section information and the levees to appear on the cross section schematic The next picture shows a cross station used in this example with the levee on the right overbank XS Levee Data B Ground j 670 Enter station and elevation points to mark levee Levee SRE SELECT Te Bank Sta Left Right Station 460 Elevation e70 OK Cancel Defaults Clear 665 Elevation ft 660 655 0 100 200 300 400 500 600 700 Station ft In this specific case the definition of the levee was unnecessary since the water will overflow the cross section on the left end of the cross section before flowing on the right channel Inspect each cross section and determine whether or not it needs levees Add levees where applicable When finished save your geometry data again i Bridge amp Culvert Data Upstream Bridge This section w
29. llustration for spacing these cross sections In this figure Lc represents the contraction reach length and Le is the expansion reach length Typically Lc lt Le as shown in the picture These distances can be determined by field investigation during high flows or by examining the TIN to locate the point in the channel where the flowpath has fully expanded or contracted The flowpath lines should be parallel to each other where cross sections and 4 are placed Cross sections 2 and 3 should be placed within a short distance of the upstream and downstream ends of the bridge The purpose Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 13 of 42 Texas A amp M University Zachry Department of Civil Engineering of placing these cross sections near the bridge is to capture the natural ground elevations directly next to the bridge A good rule of thumb is to draw cross sections 2 and 3 at the toe of the bridge embankment on their respective sides of the bridge Note More information on this topic can be found on pages 6 23 to 6 26 in the HEC RAS User s Manual There is also an empirical method of determining the distances Lc and Le based upon channel slope ratios for bridge width opening to the total floodplain width and ratios of Manning s roughness values n for the main channel and floodplain explained in this section of the manual This approach however is not used in this tutorial
30. n HEC RAS user interface Select File Import Geometry Data GIS Format In the browser which appears navigate to your working directory where you stored the RAS GIS import file GISZRAS notice it is called GISZRAS RASImport sdf and select it Select OK in the browsing window The Import Options window with four tabs will appear Make sure that US Customary Units is selected on the first tab then press Next The second tab is for selecting river reach stream lines For this tutorial we have only one river and one reach make sure it appears in the import window with the drop down arrow then select Next The third tab is Cross Sections and IB Nodes This tab lists all of our cross sections as well as the two bridges Scroll down to see them all Make sure all of the boxes are checked The window should look like the picture below The fourth tab is grayed out because we did not create any storage areas or storage connections in this tutorial Therefore we are finished selecting the data we want to import so select Finished Import Data from the Import Options window Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 21 of 42 Texas A amp M University Zachry Department of Civil Engineering Import Options The imported RS can be edited here change the import River and Reach names on the previous tab H M M M M S ct Cros
31. only one reach The following box will appear Type in a name for the river and reach you selected then click OK Assign River and Reach Names x River Riveri Reach Reacht OF Help Cancel After labeling the river reach open and examine the attribute table for the river centerline River Notice that many of the fields in the attribute table have been automatically populated iii Network Connectivity Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 9 of 42 Texas A amp M University Zachry Department of Civil Engineering Next we will populate the ToNode and FromNode fields in the River centerline attribute table From the HEC GeoRAS toolbar select RAS Geometry Stream Centerline Attributes Topology The following box will appear Create River Topology j X Stream Centerline Terrain TIN ftin_2f OF Help Cancel Select the name of your stream centerline and terrain TIN in the drop down menus and then select OK After you do the following message will appear Create River Topology X River topology successfully created Next to determine the length of each reach and populate the FromSta and ToSta fields in the attribute table from the HEC GeoRAS toolbar select RAS Geometry Stream Centerline Attributes Lengths Stations from the menu You ll receive the following message Calculate L
32. owpaths feature class but following these steps will save you time In the HEC GeoRAS toolbar select RAS Geometry Create RAS Layers Flowpath Centerlines The following menu will appear asking if you would like to copy the stream centerline as your main channel flowpath line Create Flowpath Layer X The stream centerline is defined Do you want to copy the existing stream centerline shapes into the Flowpath layer Mo Cancel Select Yes In the following window select the Stream Centerline and Flowpath Centerlines feature classes and click OK and the following message window will appear Click OK Create Flow Paths x Flow Path lawer created successfully You still need to digitize the overbank flowpath lines in the downstream direction Do this in an edit session with Create New Feature as the task and Flowpaths as the target in the Editor toolbar Draw the flowpaths using the same methods described above for digitizing the stream centerline and bank lines Next you need to label each flowpath line using the Assign Line Type tool LL After clicking on the Assign Line Type tool click on a Flowpaths line and then select the correct option 1 e right or left in the window that pops up and click OK Repeat with all three flowpaths Note the right flowpath is the line on your right if you were looking downstream and water was hitting you in the back Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285
33. pstream of the first bridge That implies that the XS Cut Lines have to be redefined and the entire process repeated again Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 28S HECGeoRAS after FO doc Page 41 of 42 Texas A amp M University Zachry Department of Civil Engineering These materials may be used for research and educational purposes only Please credit the authors and the Zachry Department of Civil Engineering at Texas A amp M University All commercial rights reserved Copyright 2007 Texas A amp M University Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 42 of 42
34. rowse to its location select your working directory for the output file location and input 2 as the rasterization cell size since our original DEM has a 2 foot cell size When you ve made these selections select OK Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 38 of 42 Texas A amp M University Zachry Department of Civil Engineering Layer Setup for HEC R AS PostProcessing x Analysis Type O Existing Analysis f New Analysis SteadyFlow FAAS GIS Export File F TutorialsAS Creek RAS export am E Terrain Terrain Type Select Terrain f Single f TIN Grd F sTutornal Given_Catastin 2ft Multiple OTM Tiles Layer a E Output Directory FAT Utorialy forking Directom S teadyFlow Output GeoD atabase SteadyFlow mdb Rasterzation Cell Size 2 map units OK Help Cancel This action will create a new data frame with the name of your new analysis in this example SteadyFlow Look at the bottom of the ArcMap table of contents and you will see the new data frame with the TIN added to it Next on the HEC GeoRAS toolbar select RAS Mapping Read RAS GIS Export File This action will import the HEC RAS results as feature classes River2D XS Cut Lines and Bounding Polygon to your new data frame It may take a few minutes to finish depending on your computer Additionally a new geodatabase with you analysis name SteadyFlow will be created in your
35. rsity Zachry Department of Civil Engineering Pan 3 BU BD SR l Upstream Bridge Dow nstreani Distance Width Distance l l USACE HEC RAS User s Manual 2002 The following picture shows the Deck Roadway Data editor after the appropriate information has been entered for the upstream bridge Note that the Distance value depends on where you located your cross sections and most likely will not be 38 4 ft for you Deck Roadway Data Editor Del Row Ins Row Downstream high chord low chord 669 82 0 669 82 2 3 9 669 82 3 9 669 82 5 15 669 51 5 15 669 81 4 24 43 669 73 24 43 669 73 5 24 82 669 73 24 82 669 73 6 26 21 669 73 26 21 669 73 27 39 669 72 27 39 669 72 669 66 44 22 669 66 U S Embankment SS fo D S Embankment SS fo Weir Data Max Submergence 4 95 Min Weir Flow El Weir Crest Shape Broad Crested Ogee OK Cancel Clear Copy US to DS Enter distance between upstream cross section and deck roadway ff Culvert Next in the Bridge Culvert Data editor select the Culvert button This will bring up the Culvert Data Editor window The following picture shows this editor after the appropriate information has been entered for the upstream bridge Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 28S HECGeoRAS after FO doc Page 29 of 42 Texas A amp M University Zachry Department of Civil Engineering Enter the inform
36. rts Bridges Ineffective Flow Areas Ineff reas Blocked Obstructions BlockedDbs Land Use Jlandse Levee Alignment levees Levee Points leveePoints 0 Inline Structures lInineStructures Lateral Structures Lateral5tructures Storage Areas Storage reas OO Storage Area Connections 5AConnections OF Help Cancel Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 28S HECGeoRAS after FO doc Page 5 of 42 Texas A amp M University Zachry Department of Civil Engineering It may take a few seconds but once the RAS layers are successfully created you will see the following message and the new layers will appear in the table of contents Create All Layers Feature layers created successfully Complete layers by digitizing Features The following sections discuss how to create digitize each individual RAS layer 1 Stream Centerline Layer This layer will be used to digitize draw the river reach network for the system you are studying For this tutorial we will digitize only one stream with one reach It is possible though to model networks of streams with HEC GeoRAS but that will not be discussed here Note Always digitize the stream in the direction of flow That is you must begin at the most upstream end of the stream and work your way downstream ending at the outlet or beginning of the next downstream reach In ArcMap on the Editor toolbar select Editor Start Editing from the drop
37. ry Department of Civil Engineering Add the TIN named TIN_2ft to the map by selecting the Add Data button Navigate to the directory where the data are stored select TIN_2ft and press the Add button Once the TIN has been added to ArcMap your map should look similar to the figure below Notice the river labels in this figure will not be on your map The rivers on the figure are labeled so that you can distinguish between the study reach Cypress Rapids Creek and the larger Guadalupe River RASLayers mxd ArcMap Arc iew File Edit View Insert Selection Tools Window Help Li gt m a do al x K om 117 785 7 I amp 5 R Editor gt Ed Task Create New Feature Ta ide e Te Ge EE A Ch Gab roo E E KEELER OED Hh OMS E oo _ _ o amp Layers tin_2f Soft Edge Elevation 741 111 758 724 222 741 111 Ml 707 333 724 222 MB 690 444 707 333 E 673 556 690 444 Ml 656 667 673 556 Ml 639 778 656 667 622 889 639 778 606 622 889 janj na J gt 2252487 88 13823440 31 Feet Wy c We are now ready to create the RAS layers in ArcMap which are used to create geometric data sets that will be modeled in HEC RAS Only two RAS layers are needed to map a floodplain Stream Centerline and Cross Section Cutlines All other layers are optional In this tutorial we will use a few of the optional RAS layers The RAS layers can be created in one
38. s Section Properties to Import nain 114374499774 a ies Note If at any point you need to revise or add cross sections or bridges to your data Set you can add them in GIS i e draw and attribute them then return to the Import Options menu in HEC RAS and import only the sections which are new to your data set by checking the appropriate boxes Now your Geometric Data window should look similar to the following picture A georeferenced schematic of your river system will appear in the window To save this data in the Geometric Data window select File Save Geometry Data and enter a filename in the Title slot of the dialog box I descriptively named my geometry data Geometry Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 22 of 42 Texas A amp M University Zachry Department of Civil Engineering Geometric Data File Edit View Tables Tools Help BARY Salg eac rea ion Tools R act 3520 280 4397 467 b 4322 349 Er EEn aaa 4659 894 yo 2926 459 2592 891 2290 983 L 2181 003 2039 310 1780 921 227 0929 619 6921 129A 711 id mf 2255890 00 13817390 00 c Entering Additional Data in the HEC RAS Model We will now use the Geometric Data window to help us enter more data about the stream 1 Cross Section Points Filter HEC RAS allows a maximum of 500 data points per cross section HEC RAS has a cross
39. te points and were filtered Select Close on this window and then select OK on the Cross Section Points Filter window In the Geometric Data window click on File Save Geometry Data to keep these changes li Manning s Roughness Values n Next we need to enter Manning s n values for each cross section In the Geometric Data window select Tables Manning s n or k values In the Edit Manning s n or k Values window select All Rivers from the drop down box in the River option You will see all of your cross sections and two bridges listed in the table with blank spaces where you will type in your n values The fields n 1 and n 3 are for the Manning s n values for the overbanks floodplains Enter 0 1 in these fields for all cross sections but not for the bridges Similarly the field n 2 is for the main channel Manning s n value Enter 0 05 in this field for all cross sections but not for the bridges Once you ve populated the whole table select OK The window will close Make sure you save your geometry data again to retain this information Z Teaching CVEN658 GISNewExercises SarahMeyer Final 2007 05 285 HECGeoRAS after FO doc Page 24 of 42 Texas A amp M University Zachry Department of Civil Engineering Edit Manning s n or k Values Channel n Values have alight green Reach lt Al Regions background selected Area Edit Options Add Constant Multiply Factor set Values Replace
40. the bank lines Two foot contours are provided in the data set and can be added to the map to assist you The following picture shows an example of drawing bank lines You will have to zoom in closely to the section of the river you are working with You want the bank lines to represent the edges of the main channel In the following picture you will see that the bank line is drawn at what appears to be the edge of the creek at the top of the steepest grade from the creek and before the land planes out again on a more gradual slope along the floodplain Note that bank lines do not coincide with contour lines v Flowpath Centerlines Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 11 of 42 Texas A amp M University Zachry Department of Civil Engineering The flowpath centerline layer is a set of lines that follows the center of mass of the water flowing down the river For the main channel the stream centerline is the flowpath centerline For the channel overbanks floodplains the flowpath centerline is located in the center of the overbank and is set slightly outside the main channel bank lines Note that the widths of the floodplains are unknown thus far The flowpath centerlines are used to calculate the downstream reach lengths between cross sections Flowpath centerlines are also created from upstream to downstream according to the following instructions You have already created a Fl
41. tion Enter Edit Number of Profiles 2000 max and then click on the Apply Data button Next select Options Edit Profile Names from the top menu and in the table that pops up enter the information displayed in the following picture Click on OK Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 28S HECGeoRAS after FO doc Page 33 of 42 Texas A amp M University Zachry Department of Civil Engineering Edit Profile Hames 16 Characters Max Profile Profile Name 10 year A Year In the Steady Flow Data window you will see that the most upstream station is already listed We will add a second flow change location at the cross section immediately upstream of the second bridge The river station of this second cross section will vary based upon where you placed your cross sections Use the network schematic in the Geometric Data window to identify this cross section Back to the Steady Flow Data window select the cross section from the drop down menu next to River Sta and then click on the Add a Flow Change Location button A second row will be added to your Steady Flow Data table with this river station listed Now we want to enter the peak flows in cfs for these two river stations for the 10 50 and 100 year events The following picture shows the peak flows listed for these river stations Select the Apply Data button after you enter all the flows These peak flows were obtained by running the HEC HMS model
42. tions Null Ineffective Areas Nul Blocked Obstructions Nul Elevation Volume Null Nodes Table Nul Apple HEC GeoRAS Symbaology OF Help Cancel b Exporting GIS Data From the HEC GeoRAS toolbar select RAS Geometry Extract GIS DATA menu item The following window will appear Choose a file name and directory to save the data in Here we will call the file by its default name GIS2RAS and save it in your working directory Select OK pE File Mame F Tutoralorking_Directory GIS2AAS a i Help Cancel Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 19 of 42 Texas A amp M University Zachry Department of Civil Engineering While HEC GeoRAS is exporting the data which takes several seconds a series of information messages appear Select OK for each message prompt Finally the following message will appear signaling successful exporting of GIS data Select OK Export GIS Data X 605 data For RAS exported successfull 5 Hydraulic Analysis in HEC RAS This section presents how to perform a one dimensional steady flow analysis of the creek using HEC RAS Hydrologic Engineering Center River Analysis System If not installed in your computer download the file HEC RAS313_Setup exe from http www hec usace army mil software hec ras hecras download html and install HEC RAS 3 1 3 according to the instructions For your convenience the file HEC RAS313_Setup
43. vil Engineering Set boundary for one profile at a time Steady Flow Aeach Storage Area Optimization OF Cancel Help Enter to make the boundary for selected location normal depth You are now finished entering steady flow data Select File Save Flow Data from the Steady Flow Data window Give this file a name for example Steady_Flow and save it in your RAS file folder in your working directory You can now close the Steady Flow Data window ii Run Steady Flow Analysis We are now ready to do a steady flow hydraulic analysis of the stream In the main HEC RAS user interface press the Steady Flow Simulation button E You ll see the following window appear The names of your Geometry File and Steady Flow File will be listed in the options Choose the Subcritical option as your Flow Regime Ef steady Flow Analysis File Options Help Plan Short ID Geometry File Geometry Steady Flow File Se ady Flow Flow Regime Plan Description Subcritical Supercritical C Mixed Pana Te SAR o 3 E nter to compute water surface profiles Click on COMPUTE to run the steady flow analysis If it is successful you will see the message below if not you may receive a warning error message which you will have to address before the model will run successfully Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 36 of 42 Texas A amp M University
44. working directory Your map should look like the following picture Z Teaching C VEN658 GISNewExercises SarahMeyer Final 2007 05 28S HECGeoRAS after FO doc Page 39 of 42 Texas A amp M University Zachry Department of Civil Engineering Examine the attribute table of the new Bounding Polygon feature class You will notice that there are three rows in the table one for each flood event 10 50 and 100 year flows The purpose of the bounding polygon is to limit the extents of the floodplain You ll notice that the bounding polygon will conform to the boundaries of any levees you placed in the model unless they are overtopped by the flood flows 7 Mapping Floodplains Using GIS Floodplain mapping is completed in two steps First a water surface TIN will be constructed from the cross section water surface elevations We will have three TINs one from each flood frequency Second the water surface TIN is intersected with the digital terrain model to create floodplain polygons for each flow scenario In the HEC GeoRAS toolbar select RAS Mapping Inundation Mapping Water Surface Generation The following window will appear Select all three water surface profiles hold down Ctrl and then select OK Z Teaching CVEN65S GISNewExercises SarahMeyer Final 2007 05 25 HECGeoRAS after FO doc Page 40 of 42 Texas A amp M University Zachry Department of Civil Engineering Water Surface TIM x Select water surtace profile 10 Year
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