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 layers were overlaid with digital soils information for two 71/2' quadrangles in the Cascade Mountains of Washington. The data layers were then integrated 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 hazard prediction.