| This study uses a Geographic Information System (GIS) to analyze and correlate available digital geologic, geomorphic and geotechnical data with a digital landslide inventory of a portion of Santa Clara County, California. Properties found to have the greatest influence on hillslope stability are lithology and degree of slope. Less influential properties are hillslope aspect and vertical land surface curvature. The results of the analysis are used to develop a method of determining relative hillslope stability across the study area, which is depicted in the form of a map at 1:62,500-scale. A comparison of the Relative Hillslope Stability map with a recent landslide inventory map reveals that the majority of the recent landslides mapped fall within stability groups of 5 to 10, (moderately to highly unstable). The strong correlation of these maps indicates that the Relative Hillslope Stability map is a useful tool for regional planning and development within the study area. |
