GIS and Distributed Watershed Models. II: Modules, Interfaces, and Models

This paper presents representative applications and models that can take advantage of spatially distributed data in a geographic information system (GIS) format for watershed analysis and hydrologic modeling purposes. The intention is to inform hydrologic engineers about the current capabilities of GIS, hydrologic analysis modules, and distributed hydrologic models, and to provide an initial guide on implementing GIS for hydrologic modeling. This paper also discusses key implementation issues for individuals and organizations that are considering making the transition to the use of GIS in hydrology. Widespread use of GIS modules and distributed watershed models is inevitable. The controlling factors are data availability, GIS-module development, fundamental research on the applicability of distributed hydrologic models, and finally, regulatory acceptance of the new tools and methodologies. GIS modules and distributed hydrologic models will enable the progression of hydrology from a field dominated by techniques that require spatial averaging and empiricism to a more spatially descriptive science.