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5 c 1-hec-georas_part1

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T
Taoufik Byou

This document provides an overview of a workshop on using HEC-GeoRAS to link GIS and hydraulic modeling software. The workshop is aimed at engineers, GIS professionals, and planners. It introduces HEC-GeoRAS and HEC-RAS software, the process of generating spatial data in HEC-GeoRAS from GIS layers, importing it into HEC-RAS, and exporting modeling results for mapping floodplains in GIS. Key topics covered include developing stream centerlines, cross sections, flow paths, and other data layers in GIS, validating data, running hydraulic models in HEC-RAS, and mapping inundation polygons with HEC-GeoRAS.

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HEC-GeoRAS Walkthrough Workshop Ryan Meekma, GISP Gregory Byard, P.E., CFM
©2013 University of Illinois Board of Trustees. All rights reserved. For permission information, contact the Illinois State Water Survey.
Welcome (Who is in the Audience?) Engineers • HEC-RAS experts GIS Professionals • GIS experts Engineering + GIS = HEC-GeoRAS City Planners Flood Plain Managers
Why Are We Here? Learn about: • Data • GIS • Engineering • Geo-RAS • HEC-RAS • TROUBLESHOOTING Geo-RAS Walkthrough • Not a live DEMO • Screenshots captured at each step
Agenda • Introduction to HEC-GeoRAS and Spatial Data • Generating Required Data in HEC-GeoRAS • HEC-GeoRAS to HEC-RAS • Tools and Tips for modeling & managing spatial data in HEC-RAS • HEC-RAS to HEC-GeoRAS • Post Processing in GIS • Additional HEC-GeoRAS capabilities (as time allows)
Benefits of Using HEC-GeoRAS • Spatial Relationships – Link input data, hydraulic modeling, and final floodplain mapping • Better utilize detailed topographic information – Make use of LiDAR / survey data – Increase accuracy and precision in overbank • Improve modeling efficiency – Quickly identify impacts of modeling changes and areas of concern – Utilize GIS staff to aid in model development and mapping • Visualize results to improve model accuracy – Easily identify areas of basin interaction
Software Requirements • HEC-GeoRAS – HEC-GeoRAS 4.3.93 for use with ArcGIS 9.3 – HEC-GeoRAS 10 for use with ArcGIS 10.0 (today’s discussion) – HEC-GeoRAS 10.1 for use with ArcGIS 10.1 (just released) • ArcGIS – Required Extensions • Spatial Analyst • 3D Analyst • HEC-RAS – Full functionality of HEC-GeoRAS 4.3.93 requires HEC-RAS 4.0 or later – RAS Mapper Utility requires HEC-RAS 4.1.0
Identify the Scope of Work Type Level of Analysis • Regulatory Use – Detailed Floodplain Study – Approximate Floodplain Study • Sediment Transport • Research and Scientific Analysis Study Extents • Upstream and downstream extents, tributaries, etc. • Available data • Access to survey data • Metadata (digital data is useless without it!)
Metadata, Metadata, Metadata (We hate it until we need it) What is Metadata? • Descriptive • Data about data • Content about content • Data about content Why do you need Metadata? • It answers questions about the integrity / quality of data used in modeling. – Where did it come from – Who created it – How was it created – When was it created – Why was it created – Who published the data – Was the data ever published – Did data go through a QA/QC process – What is the RMS Error
Digital Data Creation - Flowchart Figure 3-1 from HEC-GeoRAS User’s Manual v10 Tips
GIS Geo-RAS Walkthrough Version 10.0
New MXD
Turn on Extensions
Add Data
Digital Data Creation Projections Coordinate Systems • Units – Feet – Meters File Management • File location affects processing time • File paths are limited to <128 characters with no “wildcard” characters
Save MXD – Set File Path
Turn on Hec-GeoRAS Toolbar
HEC Geo-RAS Toolbar
Digital Data Creation Supported topographic data • DTM – DEM GRID • Can be tiled to improve processing – TIN • May allow for faster processing over large areas • Should be generated from the LiDAR points • Survey Points – Supplement the DTM within the channel • Manual Elevations – For lateral structures (with interpolation between points), ineffective flow areas, blocked obstructions, levees
TIN
DEM
Orthophoto
Create RAS Layers “make it if you need it” (walk through) or “all at once” (this slide only)
Create Stream Centerline Layer
Layer Name and Filepath
5 c 1-hec-georas_part1
Create XS Cut Lines Layers
Layer Name and Filepath
What Have We Created?
Geo-RAS Data Requirements Minimum Requirements • DTM (single or multiple) • Stream Centerline • Cross Section Cut Lines Existing Data can be loaded / copied to blank feature classes Optional Data • Flow Path Centerlines • Main Channel Banks • Land Use (for Manning’s n) • Bridges/Culverts • Inline Structures • Levee Alignments • Ineffective Flow Area • Lateral Structures • Storage Areas • Storage Area Connections Tips
Digital Data Creation General Editing Rules • Stream centerlines and flow paths are digitized upstream to downstream • Cross sections, inline structures, and bridges/culverts are digitized from left to right looking downstream • Use directional symbology for cross sections and stream centerlines during digitization – Layer Properties -> Symbology -> Symbol -> Arrow at End • Flip reversed cross sections rather that re-digitizing Tips
Developing Stream Centerline • River stationing is based on the Stream Centerline – Use the most up to date aerial photography available to check for development since the most recent orthophotography – Ensure agreement between the aerial photography and DTM • Junctions (aka confluences) – Snapping • River Reach naming • Downstream reach lengths are based on the Flow Path Centerlines (Profile Baseline), which may or may not follow the Stream Centerline for large events
Simple Data Loader
• Start ArcMap Edit session • Select your “Input data” • Object Loader Summary • & Repeat for other Layers • Select your “Target” – River Simple Data Loader
Tule Creek - Tributary Baxter River – Lower Reach Baxter River – Upper Reach
Assign River and Reach Names • Flow Path ID Icon
Line Direction and Label
Developing Cross Section Data Manual Cross Sections • Digitized left to right looking downstream • Perpendicular to the direction of flow (cross sections can have bends) • Must not intersect • Cross the stream line only once • Must be contained within DTM • Can be imported from previously digitized data
Developing Cross Section Data Automated Cross Sections • Specified interval and width • Perpendicular to stream centerline • “This is NOT the preferred method and should be used with caution because the lines are not generated following the guidelines necessary for modeling one-dimensional flow.” - HEC-GeoRAS User’s Manual v10
Load Cross Sections (using simple data loader, same process as Stream Centerline)
Line Direction and Label • NOTE: XS has not been attributed yet
Manually Digitizing Cross Sections • Begin Edit Session • Choose Layer to Edit
Manually Digitizing Cross Sections • Click on XSCutlines • Begin Digitizing FLOW DIRECTION
Manually Digitizing Cross Sections • Double Click to End Sketch • Save Edits FLOW DIRECTION
Developing Flow Path Centerlines (optional … sort of) • Necessary for downstream reach length extraction • May specify either: – Main channel flow path – Main channel, left overbank, right overbank flow paths • Main channel flow path may utilize stream centerline • Consider the flow path over the range of discharges to be modeled
Create Flow Path
Flow Path Layer
Select Flowpath & Linetype button Types of Flowpaths • Three types of lines – Centerline – Left overbank – Right overbank Flowpath Usage • Defines the downstream reach lengths between cross-sections in the main channel and over bank areas
Developing Channel Bank Data (optional) Bank Lines = RED Bank Points = YELLOW (Bank points are created where bank lines intersect cross section line)
Finished Creating RAS Layers • Layer Setup
RAS Layer Setup
Stream Centerline Attributes • Layer Name = River (feature class name) • Terrain = Source selected in Layer Setup (TIN)
What Have We Created for the Water Line? • RiverCode • ReachCode • FromNode • ToNode • FromSta (From Station) • ToSta (To Station)
XS Cut Line Attributes • Only showing Required Layers above
What Have We Created for the XS Layer? (EVERYTHING! To get started with modeling at least…)
Export RAS Data • Select Output Folder • Name File
Exported RAS Data Two files were created: • Next step is importing data into a HEC-RAS model
Transitioning from Geo-RAS to RAS Gregory Byard, P.E., CFM byard@illinois.edu (217) 244-0360
Transitioning from Geo-RAS to RAS Open HEC-RAS • Start a new project in HEC-RAS • From the Geometric Data Editor, import the RAS GIS Import File • Select the appropriate .sdf file
Import Geometry Data Select Unit System • Consider the linear units of the DTM • Consider units of data with which to merge • Select ‘Next’
Import Geometry Data River Reach Stream Lines • Revise river and reach names as necessary • Select which stream lines to import • Select the merge mode • Select ‘Next’
Import Geometry Data Cross Sections and IB Nodes • Choose which cross sections, bridge/culvert, inline structure, and lateral structure to import • Select cross section properties to import • Assign river stations • Assign stationing offsets • Select ‘Next’
Import Geometry Data Storage Areas and Connections • Choose which to import • Assign names • Select volume- elevation or outline • Select ‘Finished- Import Data’ • Save geometry file
Review Imported Data Things to review • Expanse of Manning’s n values • Location of bank station data • Add/move/delete ground points (check for gaps, erroneous data) • Add/move/delete levees, ineffective flow areas, and blocked obstructions • Compare and merge cross section elevation data • Junction connection and length
Graphical Cross Section Editor Tip Hold ‘Ctrl’ to activate measure tool Hold ‘Shift’ to activate pan toolThroughout HEC-RAS
Graphical Cross Section Editor
Cross Section Points Filter
Modifying Cross Section Extents Very important for proper floodway mappingTip
Modifying Cross Section Extents (If you choose ‘Accept edits and leave cut line alone’)
From Import to Running Model What still needs to be added? • Data purposefully omitted from Geo-RAS • Hydraulic structure data – Opening geometry, connections • Additional levee, ineffective flow, block obstructions data – Opening geometry, revised elevations, etc. • Detailed channel geometry • Flow data (with boundary conditions) Reminder: “Importing data generated from GIS layers will not create a complete river hydraulics model”
Initial Review of Results Compute the Steady or Unsteady Flow Analysis • Review the results and adjust your model as necessary – Check especially for • Cross sections that cannot contain the range of flows • Consistent levee overtopping • Ineffective areas around bridges / natural floodplain constrictions • Tools for review – View Cross Sections – View Profiles – View 3D Multiple Cross Section Plot • Set Azimuth Angle to 90
View Cross Sections
View Profiles
View 3D Multiple Cross Section Plot
RAS Mapper Note: Need DTM in float (.flt) format To convert a DEM, use “Raster to Float (Conversion)” tool in ArcMap
RAS Mapper
RAS Mapper Note: Remove layers and reload following edits, they do not update automatically
Processing HEC-RAS Results Ryan Meekma, GISP rmeekma@illinois.edu (217) 244-6627
Export GIS Files from HEC-RAS 1.) Open HEC-RAS Model 2.) FileExport GIS Data…
Export GIS Files from HEC-RAS 3.) GIS Export (complete fields) 4.) Turn On HEC-GeoRAS Toolbar in ArcMap 10
Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 6.) Save MXD RAS Mapping Layer Setup 5.) Importing the RAS GIS Export file SDF Conversion to XML
Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 7.) Complete Dialog Box • Point to RAS GIS Export File • Set file path to DTM • Set Output Directory
Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 8.) RAS Mapping Toolbar 9.) Watch Magic
Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 9.) Data Processing Completed
Inundation Mapping Using GeoRAS • To begin click – RAS Mapping – Layer Setup • Populate post processing layer menu
Inundation Mapping Using GeoRAS • Next Step – RAS Mapping – Import RAS Data
Inundation Mapping Using GeoRAS • Bounding Polygon Created • Defines analysis extent for inundation mapping
Inundation Mapping Using GeoRAS • RAS Mapping – Inundation Mapping • Water Surface Generation – Pick a profile
Inundation Mapping Using GeoRAS • RAS Mapping – Inundation Mapping • Floodplain Delineation using Rasters – Pick a profile • DTMGRID – Water Surface – Positive Numbers • Water surface is higher than terrain (flooding) – Negative Numbers • Results are dry
Inundation Mapping Using GeoRAS • WARNING: refinement of flood inundation results is not covered in Geo-RAS! • The ability to judge quality of terrain and flood inundation polygons comes with the knowledge of study area and experience. • Smoothing floodplains does not count as creating hydraulically correct output. – It induces error
GIS to RAS, RAS to GIS
GIS Approach to Mapping Floodplains Using “3D Analyst” and “Spatial Analyst” Extensions in ArcMap • Extending Cross sections (Manually editing a copy of layer) • Creating a TIN from extended Cross Sections • Convert a TIN to Raster = WSEL Raster • WSEL – Land Surface = floodplain • Reclassify raster results • Convert raster to feature • Clean up the features • Create Topology Rules • Attribute Flood Hazard Lines
Update Elevations • Incorporate Survey Points into 3D XS feature class • XS must have previously extracted elevation from the land surface (DTM or DEM, TIN)
Update Elevations • Elevation Update Tool – Requires: • Point feature class • Field of elevation values
Update Elevations • XSCutlines3D feature class • Elevation Points • “ElevUpdate” field is added and includes a “1” if point is used
Update Elevations
Developing Bridge Culvert Data (optional) Same method for Inline Structures RAS Geometry | Bridges / Culverts| River/Reach Names Stationing Elevations
Developing Ineffective Flow Areas (optional) RAS Geometry | Ineffective Flow Areas | Positions
Developing Blocked Obstructions (optional) RAS Geometry | Blocked Obstructions | Positions
Developing Manning’s ‘n’ from Land Use Data (optional) RAS Geometry | Manning’s n Values | Extract n Values
Developing Levee Data (optional) RAS Geometry | Levee | Profile Completion Positions
Developing Lateral Structures (optional) RAS Geometry | Lateral Structures| River/Reach Names Stationing Elevations
Developing Storage Areas (optional) RAS Geometry | Storage Areas| Elevation Range Elevation-Volume Data
Developing Tiled Terrain Data (optional) • Need a terrain tiles feature class to serve as a look up table • Each RAS layer feature must be contained within one terrain tile polygon feature • DTMs should overlap to properly represent the terrain at the edges when using TIN models • DTMs should break at straight river reaches and not confluences • All of Chapter 9 of the GeoRAS Users Manual is devoted to this topic
Additional Reference Materials • http://www.hec.usace.army.mil/ • HEC-GeoRAS User’s Manual v10 • HEC-GeoRAS 10 Example Data Sets • HEC-RAS 4.1 User’s Manual, Applications Guide, and Hydraulic Reference Manual • Tutorial on using HEC-GeoRAS with ArcGIS 10 and HEC RAS Modeling by Venkatesh Merwade, Purdue University
Ryan Meekma, GISP rmeekma@illinois.edu (217) 244-6627 Gregory Byard, P.E., CFM byard@illinois.edu (217) 244-0360

More Related Content

5 c 1-hec-georas_part1

  • 1. HEC-GeoRAS Walkthrough Workshop Ryan Meekma, GISP Gregory Byard, P.E., CFM
  • 2. ©2013 University of Illinois Board of Trustees. All rights reserved. For permission information, contact the Illinois State Water Survey.
  • 3. Welcome (Who is in the Audience?) Engineers • HEC-RAS experts GIS Professionals • GIS experts Engineering + GIS = HEC-GeoRAS City Planners Flood Plain Managers
  • 4. Why Are We Here? Learn about: • Data • GIS • Engineering • Geo-RAS • HEC-RAS • TROUBLESHOOTING Geo-RAS Walkthrough • Not a live DEMO • Screenshots captured at each step
  • 5. Agenda • Introduction to HEC-GeoRAS and Spatial Data • Generating Required Data in HEC-GeoRAS • HEC-GeoRAS to HEC-RAS • Tools and Tips for modeling & managing spatial data in HEC-RAS • HEC-RAS to HEC-GeoRAS • Post Processing in GIS • Additional HEC-GeoRAS capabilities (as time allows)
  • 6. Benefits of Using HEC-GeoRAS • Spatial Relationships – Link input data, hydraulic modeling, and final floodplain mapping • Better utilize detailed topographic information – Make use of LiDAR / survey data – Increase accuracy and precision in overbank • Improve modeling efficiency – Quickly identify impacts of modeling changes and areas of concern – Utilize GIS staff to aid in model development and mapping • Visualize results to improve model accuracy – Easily identify areas of basin interaction
  • 7. Software Requirements • HEC-GeoRAS – HEC-GeoRAS 4.3.93 for use with ArcGIS 9.3 – HEC-GeoRAS 10 for use with ArcGIS 10.0 (today’s discussion) – HEC-GeoRAS 10.1 for use with ArcGIS 10.1 (just released) • ArcGIS – Required Extensions • Spatial Analyst • 3D Analyst • HEC-RAS – Full functionality of HEC-GeoRAS 4.3.93 requires HEC-RAS 4.0 or later – RAS Mapper Utility requires HEC-RAS 4.1.0
  • 8. Identify the Scope of Work Type Level of Analysis • Regulatory Use – Detailed Floodplain Study – Approximate Floodplain Study • Sediment Transport • Research and Scientific Analysis Study Extents • Upstream and downstream extents, tributaries, etc. • Available data • Access to survey data • Metadata (digital data is useless without it!)
  • 9. Metadata, Metadata, Metadata (We hate it until we need it) What is Metadata? • Descriptive • Data about data • Content about content • Data about content Why do you need Metadata? • It answers questions about the integrity / quality of data used in modeling. – Where did it come from – Who created it – How was it created – When was it created – Why was it created – Who published the data – Was the data ever published – Did data go through a QA/QC process – What is the RMS Error
  • 10. Digital Data Creation - Flowchart Figure 3-1 from HEC-GeoRAS User’s Manual v10 Tips
  • 15. Digital Data Creation Projections Coordinate Systems • Units – Feet – Meters File Management • File location affects processing time • File paths are limited to <128 characters with no “wildcard” characters
  • 16. Save MXD – Set File Path
  • 19. Digital Data Creation Supported topographic data • DTM – DEM GRID • Can be tiled to improve processing – TIN • May allow for faster processing over large areas • Should be generated from the LiDAR points • Survey Points – Supplement the DTM within the channel • Manual Elevations – For lateral structures (with interpolation between points), ineffective flow areas, blocked obstructions, levees
  • 20. TIN
  • 21. DEM
  • 23. Create RAS Layers “make it if you need it” (walk through) or “all at once” (this slide only)
  • 25. Layer Name and Filepath
  • 27. Create XS Cut Lines Layers
  • 28. Layer Name and Filepath
  • 29. What Have We Created?
  • 30. Geo-RAS Data Requirements Minimum Requirements • DTM (single or multiple) • Stream Centerline • Cross Section Cut Lines Existing Data can be loaded / copied to blank feature classes Optional Data • Flow Path Centerlines • Main Channel Banks • Land Use (for Manning’s n) • Bridges/Culverts • Inline Structures • Levee Alignments • Ineffective Flow Area • Lateral Structures • Storage Areas • Storage Area Connections Tips
  • 31. Digital Data Creation General Editing Rules • Stream centerlines and flow paths are digitized upstream to downstream • Cross sections, inline structures, and bridges/culverts are digitized from left to right looking downstream • Use directional symbology for cross sections and stream centerlines during digitization – Layer Properties -> Symbology -> Symbol -> Arrow at End • Flip reversed cross sections rather that re-digitizing Tips
  • 32. Developing Stream Centerline • River stationing is based on the Stream Centerline – Use the most up to date aerial photography available to check for development since the most recent orthophotography – Ensure agreement between the aerial photography and DTM • Junctions (aka confluences) – Snapping • River Reach naming • Downstream reach lengths are based on the Flow Path Centerlines (Profile Baseline), which may or may not follow the Stream Centerline for large events
  • 34. • Start ArcMap Edit session • Select your “Input data” • Object Loader Summary • & Repeat for other Layers • Select your “Target” – River Simple Data Loader
  • 35. Tule Creek - Tributary Baxter River – Lower Reach Baxter River – Upper Reach
  • 36. Assign River and Reach Names • Flow Path ID Icon
  • 38. Developing Cross Section Data Manual Cross Sections • Digitized left to right looking downstream • Perpendicular to the direction of flow (cross sections can have bends) • Must not intersect • Cross the stream line only once • Must be contained within DTM • Can be imported from previously digitized data
  • 39. Developing Cross Section Data Automated Cross Sections • Specified interval and width • Perpendicular to stream centerline • “This is NOT the preferred method and should be used with caution because the lines are not generated following the guidelines necessary for modeling one-dimensional flow.” - HEC-GeoRAS User’s Manual v10
  • 40. Load Cross Sections (using simple data loader, same process as Stream Centerline)
  • 41. Line Direction and Label • NOTE: XS has not been attributed yet
  • 42. Manually Digitizing Cross Sections • Begin Edit Session • Choose Layer to Edit
  • 43. Manually Digitizing Cross Sections • Click on XSCutlines • Begin Digitizing FLOW DIRECTION
  • 44. Manually Digitizing Cross Sections • Double Click to End Sketch • Save Edits FLOW DIRECTION
  • 45. Developing Flow Path Centerlines (optional … sort of) • Necessary for downstream reach length extraction • May specify either: – Main channel flow path – Main channel, left overbank, right overbank flow paths • Main channel flow path may utilize stream centerline • Consider the flow path over the range of discharges to be modeled
  • 48. Select Flowpath & Linetype button Types of Flowpaths • Three types of lines – Centerline – Left overbank – Right overbank Flowpath Usage • Defines the downstream reach lengths between cross-sections in the main channel and over bank areas
  • 49. Developing Channel Bank Data (optional) Bank Lines = RED Bank Points = YELLOW (Bank points are created where bank lines intersect cross section line)
  • 50. Finished Creating RAS Layers • Layer Setup
  • 52. Stream Centerline Attributes • Layer Name = River (feature class name) • Terrain = Source selected in Layer Setup (TIN)
  • 53. What Have We Created for the Water Line? • RiverCode • ReachCode • FromNode • ToNode • FromSta (From Station) • ToSta (To Station)
  • 54. XS Cut Line Attributes • Only showing Required Layers above
  • 55. What Have We Created for the XS Layer? (EVERYTHING! To get started with modeling at least…)
  • 56. Export RAS Data • Select Output Folder • Name File
  • 57. Exported RAS Data Two files were created: • Next step is importing data into a HEC-RAS model
  • 58. Transitioning from Geo-RAS to RAS Gregory Byard, P.E., CFM byard@illinois.edu (217) 244-0360
  • 59. Transitioning from Geo-RAS to RAS Open HEC-RAS • Start a new project in HEC-RAS • From the Geometric Data Editor, import the RAS GIS Import File • Select the appropriate .sdf file
  • 60. Import Geometry Data Select Unit System • Consider the linear units of the DTM • Consider units of data with which to merge • Select ‘Next’
  • 61. Import Geometry Data River Reach Stream Lines • Revise river and reach names as necessary • Select which stream lines to import • Select the merge mode • Select ‘Next’
  • 62. Import Geometry Data Cross Sections and IB Nodes • Choose which cross sections, bridge/culvert, inline structure, and lateral structure to import • Select cross section properties to import • Assign river stations • Assign stationing offsets • Select ‘Next’
  • 63. Import Geometry Data Storage Areas and Connections • Choose which to import • Assign names • Select volume- elevation or outline • Select ‘Finished- Import Data’ • Save geometry file
  • 64. Review Imported Data Things to review • Expanse of Manning’s n values • Location of bank station data • Add/move/delete ground points (check for gaps, erroneous data) • Add/move/delete levees, ineffective flow areas, and blocked obstructions • Compare and merge cross section elevation data • Junction connection and length
  • 65. Graphical Cross Section Editor Tip Hold ‘Ctrl’ to activate measure tool Hold ‘Shift’ to activate pan toolThroughout HEC-RAS
  • 68. Modifying Cross Section Extents Very important for proper floodway mappingTip
  • 69. Modifying Cross Section Extents (If you choose ‘Accept edits and leave cut line alone’)
  • 70. From Import to Running Model What still needs to be added? • Data purposefully omitted from Geo-RAS • Hydraulic structure data – Opening geometry, connections • Additional levee, ineffective flow, block obstructions data – Opening geometry, revised elevations, etc. • Detailed channel geometry • Flow data (with boundary conditions) Reminder: “Importing data generated from GIS layers will not create a complete river hydraulics model”
  • 71. Initial Review of Results Compute the Steady or Unsteady Flow Analysis • Review the results and adjust your model as necessary – Check especially for • Cross sections that cannot contain the range of flows • Consistent levee overtopping • Ineffective areas around bridges / natural floodplain constrictions • Tools for review – View Cross Sections – View Profiles – View 3D Multiple Cross Section Plot • Set Azimuth Angle to 90
  • 74. View 3D Multiple Cross Section Plot
  • 75. RAS Mapper Note: Need DTM in float (.flt) format To convert a DEM, use “Raster to Float (Conversion)” tool in ArcMap
  • 77. RAS Mapper Note: Remove layers and reload following edits, they do not update automatically
  • 78. Processing HEC-RAS Results Ryan Meekma, GISP rmeekma@illinois.edu (217) 244-6627
  • 79. Export GIS Files from HEC-RAS 1.) Open HEC-RAS Model 2.) FileExport GIS Data…
  • 80. Export GIS Files from HEC-RAS 3.) GIS Export (complete fields) 4.) Turn On HEC-GeoRAS Toolbar in ArcMap 10
  • 81. Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 6.) Save MXD RAS Mapping Layer Setup 5.) Importing the RAS GIS Export file SDF Conversion to XML
  • 82. Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 7.) Complete Dialog Box • Point to RAS GIS Export File • Set file path to DTM • Set Output Directory
  • 83. Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 8.) RAS Mapping Toolbar 9.) Watch Magic
  • 84. Export GIS Files from HEC-RAS Extract GIS Data from Hec-RAS using the Geo-RAS Tool in GIS 9.) Data Processing Completed
  • 85. Inundation Mapping Using GeoRAS • To begin click – RAS Mapping – Layer Setup • Populate post processing layer menu
  • 86. Inundation Mapping Using GeoRAS • Next Step – RAS Mapping – Import RAS Data
  • 87. Inundation Mapping Using GeoRAS • Bounding Polygon Created • Defines analysis extent for inundation mapping
  • 88. Inundation Mapping Using GeoRAS • RAS Mapping – Inundation Mapping • Water Surface Generation – Pick a profile
  • 89. Inundation Mapping Using GeoRAS • RAS Mapping – Inundation Mapping • Floodplain Delineation using Rasters – Pick a profile • DTMGRID – Water Surface – Positive Numbers • Water surface is higher than terrain (flooding) – Negative Numbers • Results are dry
  • 90. Inundation Mapping Using GeoRAS • WARNING: refinement of flood inundation results is not covered in Geo-RAS! • The ability to judge quality of terrain and flood inundation polygons comes with the knowledge of study area and experience. • Smoothing floodplains does not count as creating hydraulically correct output. – It induces error
  • 91. GIS to RAS, RAS to GIS
  • 92. GIS Approach to Mapping Floodplains Using “3D Analyst” and “Spatial Analyst” Extensions in ArcMap • Extending Cross sections (Manually editing a copy of layer) • Creating a TIN from extended Cross Sections • Convert a TIN to Raster = WSEL Raster • WSEL – Land Surface = floodplain • Reclassify raster results • Convert raster to feature • Clean up the features • Create Topology Rules • Attribute Flood Hazard Lines
  • 93. Update Elevations • Incorporate Survey Points into 3D XS feature class • XS must have previously extracted elevation from the land surface (DTM or DEM, TIN)
  • 94. Update Elevations • Elevation Update Tool – Requires: • Point feature class • Field of elevation values
  • 95. Update Elevations • XSCutlines3D feature class • Elevation Points • “ElevUpdate” field is added and includes a “1” if point is used
  • 97. Developing Bridge Culvert Data (optional) Same method for Inline Structures RAS Geometry | Bridges / Culverts| River/Reach Names Stationing Elevations
  • 98. Developing Ineffective Flow Areas (optional) RAS Geometry | Ineffective Flow Areas | Positions
  • 99. Developing Blocked Obstructions (optional) RAS Geometry | Blocked Obstructions | Positions
  • 100. Developing Manning’s ‘n’ from Land Use Data (optional) RAS Geometry | Manning’s n Values | Extract n Values
  • 101. Developing Levee Data (optional) RAS Geometry | Levee | Profile Completion Positions
  • 102. Developing Lateral Structures (optional) RAS Geometry | Lateral Structures| River/Reach Names Stationing Elevations
  • 103. Developing Storage Areas (optional) RAS Geometry | Storage Areas| Elevation Range Elevation-Volume Data
  • 104. Developing Tiled Terrain Data (optional) • Need a terrain tiles feature class to serve as a look up table • Each RAS layer feature must be contained within one terrain tile polygon feature • DTMs should overlap to properly represent the terrain at the edges when using TIN models • DTMs should break at straight river reaches and not confluences • All of Chapter 9 of the GeoRAS Users Manual is devoted to this topic
  • 105. Additional Reference Materials • http://www.hec.usace.army.mil/ • HEC-GeoRAS User’s Manual v10 • HEC-GeoRAS 10 Example Data Sets • HEC-RAS 4.1 User’s Manual, Applications Guide, and Hydraulic Reference Manual • Tutorial on using HEC-GeoRAS with ArcGIS 10 and HEC RAS Modeling by Venkatesh Merwade, Purdue University
  • 106. Ryan Meekma, GISP rmeekma@illinois.edu (217) 244-6627 Gregory Byard, P.E., CFM byard@illinois.edu (217) 244-0360