GEOGRAPHIC INFORMATION-SYSTEMS IN URBAN STORM-WATER MANAGEMENT

Increasing use of distributed, physically based urban storm water management models requires urban water managers to acquire, maintain, and utilize the extensive, spatially referenced data bases necessary to support these efforts. Geographic information systems (GIS) arc ideally suited to preparing, storing, updating, analyzing, and displaying these data in conjunction with urban storm water modeling. A physically based urban storm water runoff model is linked to a low-cost, PC-based raster GIS package to facilitate preparation, examination, and analysis of spatially distributed model inputs and parameters. Impacts of urban storm water management strategies are analyzed through preprocessing by GIS, calculation of discharge by the urban runoff model, and postprocessing and display of spatial output in the GIS. Three methods of encoding urban features in a raster GIS system are utilized: single value attributed data (SVAD), edge probability attributed data (EPAD), and central attributed raster line (CARL). The viability of the raster GIS/urban storm water model linkage in a microcomputing environment is demonstrated on a study area in the Greenbriar subdivision in Fort Collins, Colorado.