1 / 39

Application of HEC-HMS for Hydrologic Studies

Application of HEC-HMS for Hydrologic Studies. Texas A&M University Department of Civil Engineering CVEN689 – Applications of GIS in CE Instructor: Dr. Francisco Olivera Logan Burton 3/14/03. Outline. HMS and GIS Project Overview Challenges Solutions Methodology Results. HEC-HMS.

adsila
Download Presentation

Application of HEC-HMS for Hydrologic Studies

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Application of HEC-HMS for Hydrologic Studies Texas A&M University Department of Civil Engineering CVEN689 – Applications of GIS in CE Instructor: Dr. Francisco Olivera Logan Burton 3/14/03

  2. Outline • HMS and GIS • Project Overview • Challenges • Solutions • Methodology • Results

  3. HEC-HMS • HMS Hydrologic Modeling System • Developed by the U.S. Army Corp of Engineers • A numerical model that can help predict runoff volumes, peak flows, and timing of flows by simulating the behaviors of the watersheds, channels, and reservoirs.

  4. HEC-HMS Advantages • Can be applied to a variety of watersheds with different shapes, sizes and characteristics • Graphical User Interface makes the program user friendly • Software is public domain - Can be downloaded from HEC website at no cost

  5. HMS Applications • Urban Flooding This project • Flood Frequencies • Flood-loss reduction • Flood warning systems • Reservoir Design • Other Environmental studies *From HEC-HMS Applications Guide, Dec. 2002

  6. Advantages of Using GIS in Hydrologic Studies • Effective and efficient delineation of watersheds and streams • Quick extraction of watershed and stream parameters • DEMs can define the drainage basin boundaries

  7. Urban Flooding • What is an Urban Flooding Study? A hydrologic study in an urban area to analyze or predict flooding problems. Common Characteristics • Short response times • Drainage systems in place • Development plays large role watershed behavior

  8. Scope of Urban Flooding • Model and analyze existing basin • Edit model to simulate urbanization • Analyze new model to help predict impact of future development

  9. Salado Creek Basin • Location: Bexar County San Antonio, TX San Antonio

  10. Urbanized Watershed

  11. Salado Creek

  12. Required Information • Peak Flows • Runoff Volume • Flow Timing • Peak Stage* • Floodplain Delineation* *HEC-RAS is used to calculate these All of this information is required for current and future development

  13. Required Data for Analysis • DEM (30 meter) • NHD files • USGS Gauging Stations • HUC boundaries Optional: DRG topographic map

  14. GIS Challenges • Gathering Data – different sources

  15. GIS challenges • Managing and Organizing Data - Different Sources = Different Projections - Very Important to keep the metadata with the downloaded files • These problems can be easily solved by using the available tools and extensions

  16. Extensions and Tools • CRWR-Vector* - project vector data • ArcInfo – project raster data • CRWR-Raster* - merge grids • CRWR-PrePro* - data pre-processor • HEC-GeoHMS could have been used in place of PrePro *Programs written by Dr. Francisco Olivera

  17. Projecting Shapefiles • CRWR-Vector is used to project shapefiles (points, lines, polygons) • Use the project tool in the pull down menu

  18. CRWR-PrePro • Can be downloaded from Dr. Olivera’s website • Predecessor to GeoHMS

  19. HEC-GeoHMS • Can be downloaded from HEC website • Menu is very similar to CRWR-Prepro

  20. Methodology • Projected all data to UTM27 – Zone 14 • Ran CRWR-PrePro to delineate watershed - Problem appeared

  21. Problem • PrePro requires that stream lengths be greater than 1 cell • Cell size is 28.85 m

  22. Solution: Step 1 • Add point theme

  23. Step 2 • Add “Elevation” Field to attribute table

  24. Step 3 • Convert the point theme to a grid

  25. Step 4 • Merge original DEM to new grid using CRWR-Raster

  26. Step 5 • Re-run CRWR-PrePro with fixed grid

  27. Process Data • Calculate Attributes • HMS Schematic

  28. HMS Components • Basin Model • Meteorological Model • Control Specifications

  29. Basin Model • Imported from ArcView

  30. Imported Basin Model

  31. Basin Characteristics • Initial/Constant Loss Rate • Initial loss = 0.39 in • Constant loss = 0.20 in - From local soil parameters • Before Development: Northern basins – 10-25% imperviousness Southern basins - 75% imperviousness - HMS Reference Manual

  32. Meteorological Model Input from TxDot Hydraulic Manual for Bexar County

  33. Control Specifications • Rainstorm of October 17-18, 1998 was used

  34. Calibration USGS Fact Sheet FS-147-99

  35. Calibration

  36. Effects of Urbanization • After Development: Entire basin model = 75% imperviousness

  37. Results Undeveloped Basin Developed Basin • Development increased flow 10,000 cfs (16%) at this gauging station

  38. Floodplains • Input channel geometry and roughness data into HEC-RAS • Import peak flows from developed basin into HEC-RAS to calculate water surface elevations and floodplains

  39. Questions? SaladoCreek

More Related