This polygon shapefile depicts landslide hazard zones in the unincorporated areas of County of Santa Clara, California. Landslides are natural geologic phenomena that range from slow moving, deep-seated slumps to rapid, shallow debris flows. Landslide risk can be exacerbated by development. Grading for roads, home construction and landscaping can decrease hillside stability by adding weight to the top of a slope, destabilizing the bottom of a slope, and/or increasing water content of the underlying materials. Slope steepness and underlying soils are the most important factors affecting the landslide hazard. However, surface and subsurface drainage patterns also affect the landslide hazard, and vegetation removal can increase the likelihood of a landslide. If property is located in a Zone of Required Investigation, where earthquake-induced landslides could occur during a large earthquake, the local building department must require geologic studies before projects are issued permits. This layer is part of a collection of GIS data for Santa Clara County, California.The Santa Clara County Planning Office is part of the Department of Planning and Development. Their primary function is to plan and regulate land use and development within the unincorporated portions of Santa Clara County. Other responsibilities include policy analysis, GIS services, research and technical assistance relating to land use, housing, environmental protection, historic preservation and demographics. The Geographic Information Services Department has taken on all those activities related to GIS data and GIS process and procedures that cross organizational boundaries. Santa Clara County encompasses 15 cities and approximately 1.7 million people. This coverage can be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analyses of geospatial data.