Earthquake activity and its attendant effects on the earth surface have been a major concern for some time now, especially considering their negative effects in loss of human life, property damage including the emotional impact on witnesses. This study focuses on the Hayward Fault, located in the heart of population center in Contra Costa County of the San Francisco Bay Area, California.

Geographical Information System (GIS) has proved to be a valuable tool in recent years in the study and analysis of earthquakes to complement emergency response efforts. GIS has been adapted to estimate the impact of the geologic hazards on the population in the area of study, including the vulnerability of utilities, facilities and infrastructures in the event of an earthquake triggered by the Hayward Fault. The end product of this study is a GIS database for the Hayward Fault compiled from various sources including maps of geology, topography, land use/land cover and geologic hazards (i.e., landslide, fire, liquefaction, ground displacement, creep and trench) in combination with maps of community services and demography. The GIS database will provide complementary data to emergency response efforts to protect the population that will be impacted in the event of a geologic hazard including the redesign and upgrading of infrastructures crossing the fault.