AUTOMATIC EXTRACTION OF WATERSHED CHARACTERISTICS USING SPATIAL-ANALYSIS TECHNIQUES WITH APPLICATION TO GROUNDWATER MAPPING

Spatial analysis techniques were developed using a raster-based image processing system to derive geometric and morphologic characteristics of watersheds from a digital elevation model. The watershed data layer s were overlaid with digital soils information for two 71/2' quadrangl es in the Cascade Mountains of Washington. The data layers were then i ntegrated with a groundwater prediction model and maps of groundwater level zones were prepared from the digital data sets. This information can be useful in assessing the stability of slopes in landslide hazar d prediction.