With the increasing availability of digital and remotely sensed data such as land use, soil type, and digital elevation models (DEMs), Geographical Information Systems (GIS) have become an indispensable tool in preprocessing data sets for watershed hydrologic modeling and postprocessing simulation results. This study describes the terrain analysis conducted using GIS for extracting information relevant to overland flow and channel flow and the methodology for providing those analyzed data sets for hydrologic simulations of overland flow, channel flow, and ground-water flow in river basins. DEMs were utilized to derive stream networks, to determine flow direction, and to delineate watershed boundaries. The effects of DEMs with various scales on the hydrologic simulation of a river basin response were determined by analyzing those parameters derived from DEMs. Simulation of hydrologic response to one storm was conducted using GIS for a river basin. The predictive capability of this approach for simulating streamflow response was demonstrated in another storm.
Journal of American WaterResources Association, vol. 37, 957-971, 2001.