Development of a Geographic Framework for an Integrated Flood Modeling System

Oscar Robayo

Tim Whiteaker

August 10, 2004

University of Texas at Austin

Center for Research in Water Resources

Department of Civil Engineering

By

Regional Storm Water Regional Storm Water Modeling Program and Modeling Program and

Master Plan for San Master Plan for San AntonioAntonio City of

San Antonio

Modeling System

Rainfall Data:Rain gagesNexrad

Calibration Data:FlowsWater Quality

Geospatial Data:City, CountySARA, other

FloodplainManagement

IntegratedRegional Water

Resources planning

CapitalImprovemen

tPlanning

FloodForecasting

Water qualityplanning

San Antonio Regional Watershed Modeling System

“Bring the models together”

Hydrologic Information System

Hydrologic Modeling

Arc Hydro Geodatabase

Arc Hydro Data Model:A Geodatabase containing a GIS representation of a Hydrological

Information System under a case-specific database design

Geographically Integrated Flood Information System

InterfaceData Models

HEC-HMS

HEC-RAS

Flood Impact

Analysis

GIS

GeoDatabase

Arc Hydrodata model

Engineering Models

Objectives

• Develop a geographically integrated flood modeling system using ArcGIS and the HEC models using Salado Creek in San Antonio as a case study

• Drive this system with digital rain maps to generate flood maps

• Store and generate HEC flood models from an ArcGIS geodatabase

• Develop a scenario management system to generate and evaluate flood design alternatives

Bringing Models Together: Long Time Goal(Feldman, Advances in Hydroscience, Vol.12. Orlando, Fl, Academic Press, 1981)

Historical NEXRAD dataHistorical NEXRAD data – NWS and TNRIS archive – NWS and TNRIS archive

Real-time NEXRAD dataReal-time NEXRAD data - web portal services - web portal services

Forecast DataForecast Data – NWS QPF – NWS QPF

Design rainfall mapsDesign rainfall maps – 2, 5, 10, 25, 50, 100 year – 2, 5, 10, 25, 50, 100 year design rainfalls as used for FEMA floodplain studiesdesign rainfalls as used for FEMA floodplain studies

Sources of Rainmap dataSources of Rainmap data

NEXRAD WSR-88D Radars in Central TexasNEXRAD WSR-88D Radars in Central Texas(Weather Surveillance Radar-1988 Doppler)(Weather Surveillance Radar-1988 Doppler)

scanning range = 230 kmscanning range = 230 km

Stage I: Just Radar

Stage II: gages, satellite, and surface temperature

Stage III: Continuous mosaic from radar overlaps

NEXRAD Products:

Source: PBS&J, 2003

EWX – NEXRAD radar in New Braunfels

Reading Historical Archives of Reading Historical Archives of NEXRAD Datasets from InternetNEXRAD Datasets from Internet

FTP Server

Local

Internet

Real-Time NEXRAD Datasets from Web Services

Design Rainfall Maps

100yr 24h

100yr 06h 100yr 12h

Seamless End-to-End Floodplain ModelingRadar Precip Estimates (historic & real time)

Flood Inundation Mapping

Seamless End-to-End Floodplain ModelingDesign Rainfall Maps

Flood Inundation Mapping

100yr 24h

Remapping Floodplain Boundaries

Storm Frequency Analysis

Watershed Land Use Configurations

Floodplain Configurations

Wildfire Events

Urban Sprawl

Agricultural Expansion

Channel Modifications

Bridges, Culverts, Weirs

Reservoirs, Levees, Dikes

Storm water systems

Land Use Changes

Longer Records

New Extreme Events

Case Study: The San Antonio River Basin

Source: PBS&J, 2003

RC1 RU

09R CO

08R CO

07R CO06R CO

04R CO03R CO

01R CO

02R CO

05R CO

Regional Watershed Modeling System Case Study

Rosillo Creekwatershed

• Arc Hydro Geodatabasefor whole watershed• HEC-HMS hydrology modelfor whole watershed• HEC-RAS hydraulic model for Rosillo Creek

Salado Creek watershed

Components:

Bexar County

Integration of Components

“A Flood Simulation and Information System that will streamline the simulation process of all the relevant model components”

Integration of:

•data acquisition systems•Hydrologic and Hydraulic modeling systems•Floodplain delineation routines•Flood Impact Analysis

Arc Hydro and HEC-Arc Hydro and HEC-HMSHMS

Arc HydroSchematic Network

HEC-HMSHydrologic

Model

Calculates Flows

Arc Hydro and HEC-RASArc Hydro and HEC-RAS

Arc HydroChannel

Cross Sections

HEC-RASHydraulic

Model

Calculates Water Surface

Elevations

InformationInformation FlowFlow

HEC-HMS

HEC-RAS

Rainfall

Runoff

Streamflow

Water Surface Elevations

4

2

3

1

Flow Change PointsFlow Change Points

HEC Data Storage System HEC Data Storage System (DSS)(DSS)

(binary data file system shared by HEC (binary data file system shared by HEC

models)models) An An exact exact

replicareplica of the of the binary DSS binary DSS files is stored files is stored in the ArcGIS in the ArcGIS geodatabasegeodatabase

An An Arc 9 Arc 9 ToolboxToolbox exchanges exchanges data between data between DSS and the DSS and the geodatabasegeodatabase

Time series catalog

Many time series

NEXRAD Map to Flood Map NEXRAD Map to Flood Map in Arc 9 Model Builderin Arc 9 Model BuilderFLO

ODPLAIN MAP

Flood map as output

Model for flood flow

Model for flood

depth

HMS

NEXRAD rainfall map as input

Map2Map Workflow for FTP Ingest

Map2Map Workflow for Design Storms

Conclusions

Model Integration Geographic Integration

Arc Hydro and Interface Data Models Information Exchange Points Data Bridges

Implemented in Arc 9.0 ModelBuilder Adaptable for ingestion of historic,

real time, forecast, and design precipitation inputs

Map to Map DemoMap to Map Demo