Application of HEC-Application of HEC-HMS for Hydrologic HMS for Hydrologic

StudiesStudiesTexas A&M UniversityTexas A&M University

Department of Civil EngineeringDepartment of Civil EngineeringCVEN689 – Applications of GIS in CECVEN689 – Applications of GIS in CE

Instructor: Dr. Francisco OliveraInstructor: Dr. Francisco OliveraLogan BurtonLogan Burton

3/14/033/14/03

OutlineOutline

HMS and GISHMS and GIS Project OverviewProject Overview ChallengesChallenges SolutionsSolutions MethodologyMethodology ResultsResults

HEC-HMSHEC-HMS

HMS Hydrologic Modeling HMS Hydrologic Modeling SystemSystem

Developed by the U.S. Army Corp of Developed by the U.S. Army Corp of EngineersEngineers

A numerical model that can help A numerical model that can help predict runoff volumes, peak flows, predict runoff volumes, peak flows, and timing of flows by simulating the and timing of flows by simulating the behaviors of the watersheds, behaviors of the watersheds, channels, and reservoirs.channels, and reservoirs.

HEC-HMS AdvantagesHEC-HMS Advantages

Can be applied to a variety of Can be applied to a variety of watersheds with different shapes, watersheds with different shapes, sizes and characteristicssizes and characteristics

Graphical User Interface makes the Graphical User Interface makes the program user friendlyprogram user friendly

Software is public domainSoftware is public domain

- Can be downloaded from HEC - Can be downloaded from HEC website at no costwebsite at no cost

HMS ApplicationsHMS Applications

Urban FloodingUrban Flooding This projectThis project Flood FrequenciesFlood Frequencies Flood-loss reductionFlood-loss reduction Flood warning systemsFlood warning systems Reservoir DesignReservoir Design Other Environmental studiesOther Environmental studies

*From HEC-HMS Applications Guide, Dec. 2002*From HEC-HMS Applications Guide, Dec. 2002

Advantages of Using GIS in Advantages of Using GIS in Hydrologic StudiesHydrologic Studies

Effective and efficient delineation of Effective and efficient delineation of watersheds and streamswatersheds and streams

Quick extraction of watershed and Quick extraction of watershed and stream parametersstream parameters

DEMs can define the drainage basin DEMs can define the drainage basin boundariesboundaries

Urban FloodingUrban Flooding

What is an Urban Flooding Study?What is an Urban Flooding Study?A hydrologic study in an urban area A hydrologic study in an urban area to analyze or predict flooding to analyze or predict flooding problems. problems.

Common CharacteristicsCommon Characteristics• Short response timesShort response times• Drainage systems in placeDrainage systems in place• Development plays large role watershed Development plays large role watershed

behaviorbehavior

Scope of Urban FloodingScope of Urban Flooding

Model and analyze existing basinModel and analyze existing basin Edit model to simulate urbanizationEdit model to simulate urbanization Analyze new model to help predict Analyze new model to help predict

impact of future developmentimpact of future development

Salado Creek BasinSalado Creek Basin

Location: Location:

Bexar CountyBexar County

San Antonio, TXSan Antonio, TX

San Antonio

Urbanized WatershedUrbanized Watershed

Salado CreekSalado Creek

Required InformationRequired Information

Peak FlowsPeak Flows Runoff VolumeRunoff Volume Flow TimingFlow Timing Peak Stage*Peak Stage* Floodplain Delineation*Floodplain Delineation*

*HEC-RAS is used to calculate these*HEC-RAS is used to calculate these

All of this information All of this information is required for current is required for current and future and future developmentdevelopment

Required Data for Required Data for AnalysisAnalysis

DEM (30 meter)DEM (30 meter) NHD filesNHD files USGS Gauging StationsUSGS Gauging Stations HUC boundariesHUC boundaries

Optional: DRG topographic mapOptional: DRG topographic map

GIS ChallengesGIS Challenges

Gathering Data – different sourcesGathering Data – different sources

Type of DataType of Data SourceSourceDEMDEM TNRISTNRIS

http://www.tnris.state.tx.us/http://www.tnris.state.tx.us/digital.htmdigital.htm

NHD filesNHD files USGSUSGShttp://nhd.usgs.gov/http://nhd.usgs.gov/

Gauging StationsGauging Stations USGSUSGShttp://water.usgs.gov/lookup/http://water.usgs.gov/lookup/getspatial?realstxgetspatial?realstx

Huc BoundariesHuc Boundaries USGSUSGShttp://water.usgs.gov/GIS/huc.htmlhttp://water.usgs.gov/GIS/huc.html

GIS challengesGIS challenges Managing and Organizing DataManaging and Organizing Data

- Different Sources = Different Projections- Different Sources = Different Projections

- Very Important to keep the metadata with - Very Important to keep the metadata with the downloaded filesthe downloaded files

These problems can be easily solved by These problems can be easily solved by using the available tools and extensionsusing the available tools and extensions

Extensions and ToolsExtensions and Tools

CRWR-Vector* - project vector dataCRWR-Vector* - project vector data ArcInfo – project raster dataArcInfo – project raster data CRWR-Raster* - merge gridsCRWR-Raster* - merge grids CRWR-PrePro* - data pre-processorCRWR-PrePro* - data pre-processor

HEC-GeoHMS could have been used HEC-GeoHMS could have been used in place of PreProin place of PrePro

*Programs written by Dr. Francisco Olivera*Programs written by Dr. Francisco Olivera

Projecting ShapefilesProjecting Shapefiles CRWR-Vector is used to project shapefiles CRWR-Vector is used to project shapefiles

(points, lines, polygons)(points, lines, polygons) Use the project tool in the pull down menuUse the project tool in the pull down menu

CRWR-PreProCRWR-PrePro

Can be Can be downloaded from downloaded from Dr. Olivera’s Dr. Olivera’s websitewebsite

Predecessor to Predecessor to GeoHMSGeoHMS

HEC-GeoHMSHEC-GeoHMS

Can be Can be downloaded from downloaded from HEC websiteHEC website

Menu is very Menu is very similar to CRWR-similar to CRWR-PreproPrepro

MethodologyMethodology

1.1. Projected all data to UTM27 – Zone Projected all data to UTM27 – Zone 1414

2.2. Ran CRWR-PrePro to delineate Ran CRWR-PrePro to delineate watershedwatershed

- Problem appeared- Problem appeared

ProblemProblem PrePro requires that stream lengths be greater than 1 cellPrePro requires that stream lengths be greater than 1 cell Cell size is 28.85 mCell size is 28.85 m

Solution: Step 1Solution: Step 1 Add point themeAdd point theme

Step 2Step 2 Add “Elevation” Field to attribute tableAdd “Elevation” Field to attribute table

Step 3Step 3 Convert the point theme to a gridConvert the point theme to a grid

Step 4Step 4 Merge original DEM to new grid using Merge original DEM to new grid using

CRWR-RasterCRWR-Raster

Step 5Step 5

Re-run CRWR-PrePro with fixed gridRe-run CRWR-PrePro with fixed grid

Process DataProcess Data

Calculate Calculate AttributesAttributes

HMS SchematicHMS Schematic

HMS ComponentsHMS Components• Basin ModelBasin Model• Meteorological ModelMeteorological Model• Control SpecificationsControl Specifications

Basin ModelBasin Model Imported from ArcViewImported from ArcView

Imported Basin ModelImported Basin Model

Basin CharacteristicsBasin Characteristics

Initial/Constant Loss RateInitial/Constant Loss Rate• Initial loss = 0.39 inInitial loss = 0.39 in• Constant loss = 0.20 inConstant loss = 0.20 in

- From local soil parameters- From local soil parameters

Before Development:Before Development:

Northern basins – 10-25% imperviousnessNorthern basins – 10-25% imperviousness

Southern basins - 75% imperviousnessSouthern basins - 75% imperviousness- HMS Reference Manual- HMS Reference Manual

Meteorological ModelMeteorological Model

Input from Input from TxDot Hydraulic TxDot Hydraulic Manual for Manual for Bexar CountyBexar County

Control SpecificationsControl Specifications

Rainstorm of October 17-18, 1998 was usedRainstorm of October 17-18, 1998 was used

CalibrationCalibrationUSGS USGS Fact Fact Sheet FS-Sheet FS-147-99147-99

CalibrationCalibration

Effects of UrbanizationEffects of Urbanization

After Development:After Development:

Entire basin model = 75% imperviousnessEntire basin model = 75% imperviousness

ResultsResults Development increased flow 10,000 cfs Development increased flow 10,000 cfs

(16%) at this gauging station(16%) at this gauging station

Undeveloped BasinUndeveloped Basin Developed BasinDeveloped Basin

FloodplainsFloodplains

Input channel geometry and Input channel geometry and roughness data into HEC-RASroughness data into HEC-RAS

Import peak flows from developed Import peak flows from developed basin into HEC-RAS to calculate basin into HEC-RAS to calculate water surface elevations and water surface elevations and floodplains floodplains

Questions?Questions?

SaladoSalado CreekCreek