Authors: Scott Lawson
Title: Ripple1D: Repurposing FEMA’s inventory of HEC-RAS models for use in Operational Flood Inundation Mapping
Presentation Type: Poster
Abstract: While methods for mapping flood inundation across broad spatial scales are advancing rapidly, HEC-RAS models often provide the most accurate inundation extents when detailed, site-specific information is needed. Ripple1D is a Python utility for generating static flood inundation maps from HEC-RAS for use in operational forecasting. A large collection of engineer-certified HEC-RAS models have been developed in recent decades in support of the Federal Emergency Management Agency (FEMA) National Flood Insurance Program (NFIP), however, accessing and using those models remains challenging. To address this, we cataloged over 150,000 FEMA HEC-RAS models using the SpatioTemporal Asset Catalog (STAC) specification. The database and associated browser make these models findable, accessible, and easily incorporated into Ripple1D workflows. To allow model interoperability with the NOAA National Water Model (NWM), Ripple1D provides tools to associate HEC-RAS model domains with NWM reach extents, execute models for a range of forecast conditions, and generate organized libraries of flood inundation maps. These tools complement the flows2fim software, and together, the software has been used to generate maps for over 500,000 river miles across the US.