GIS preprocessing for rapid initialization of HEC-HMS hydrological basin models using web -based data services

Hydrological GIS preprocessing tools are used to spatially relate different datasets for producing topologically connected watersheds and deriving attributes for model parameterization. Obtaining such information requires disparate data-sources from various websites with lengthy processing requirements. This research describes the development of HMS-PrePro, an open-source GIS preprocessing tool that was developed for the U.S. Army Corps of Engineers' (USACE) Hydrologic Engineering Center's Hydraulic Modeling System (HEC-HMS) software. HMS-PrePro provides data as a service by connecting to Esri's Living Atlas web service and extracting authoritative hydrological datasets for any watershed of interest in the contiguous United States. The datasets are saved to a local geodatabase, and spatial operations are executed to automatically delineate the watershed, derive topological connections, and estimate several common hydrologic parameters. An output basin text file is produced in HEC-HMS format for rapid model initialization.