Floodplain Analysis with ArcGIS Model Builder Donghyun Rim University of Texas at Austin

What is floodplain and why is it important? Floodplain - the lowland adjacent to a river, lake or ocean.   Floodplains are designated by the frequency of the flood that is large enough to cover them. The National Flood Insurance Program has established a minimum standard of protection against the 100-year flood. Flood damage reduction – critical interest

Work Site Austin Waller Creek

Conceptual Process Rainfall input Topologic dataset of the watershed of Waller Creek Runoff Simulation by using HEC-HMS Calculation of water surface-elevations along the channel with HEC-RAS Transformation of water-surface elevation to a unique inundation area known as flood plain

Marvelous Toolbox-MAP2MAP Developed by Oscar Robayo

Rainfall Map to Flood Inundation Map Transfer Data from NEXRAD Cell to Subbasins NEXRAD Rainfall Data Import into Geodatabase Export Timeseries of Rainfall to HEC-DSS Streamflow Hydrographs HEC-HMS Runoff Data (HEC-DSS) to GIS Water Surface Elevation File HEC-RAS Polygon as Inundated Area Convert WSE to WS TIN Import to GIS as XML Format

Data Collection 1. NEXRAD Rainfall Data 2. Topological Hydrography

3. HEC-HMS 4. HEC-RAS

5.DEM 6. Orthographic Photo

Creation of Compatible Data

Result for Rosillo Creek

Future Work Use of 10 m cell DEM for delineation of Watershed. Perform Map2Map run for Waller Creek. Use of rainfall for another time period

Special thanks to Dr. Maidment Oscar Robayo Laton Carr