GIS and distributed watershed models. II: Modules, interfaces and models

This paper presents representative applications and models that can take ad vantage of spatially distributed data in a geographic information system (G IS) format for watershed analysis and hydrologic modeling purposes. The int ention 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 organiz ations that are considering making the transition to the use of GIS in hydr ology. Widespread use of GIS modules and distributed watershed models is in evitable. The controlling factors are data availability, GIS-module develop ment, fundamental research on the applicability of distributed hydrologic m odels, and finally, regulatory acceptance of the new tools and methodologie s. GIS modules and distributed hydrologic models will enable the progressio n of hydrology from a field dominated by techniques that require spatial av eraging and empiricism to a more spatially descriptive science.