A GIS-BASED APPROACH TO IDENTIFYING POTENTIAL SEISMIC-GEOLOGIC HAZARDS TO FACILITIES AND MAJOR PIPELINES WITIHN THE SAN DIEGO WATER SYSTEM

摘要

We completed a Geographic Information System (GIS)-based assessment of potential seismic-geologic hazards to the City of San Diego (the City) water system facilities and large (≥ 24 inch) diameter pipelines located throughout and beyond the San Diego Water Department (SDWD) Service Area. Facilities that comprise the water system include storage tanks and reservoirs, water treatment plants and pumping plants, and outlet towers. The hazard assessment of these facilities and pipelines was performed using existing ArcView maps and databases, along with available consulting reports and published information. Geologic hazards assessed included ground shaking, surface fault rupture, liquefaction, and landsliding. Field reconnaissance was performed at selected SDWD facility sites and along major pipelines where potential hazards were identified. A key finding of our assessment is that field reconnaissance showed many potential hazards identified from existing ArcView geologic hazard maps have been mitigated (i.e., removed or stabilized) subsequent to their original mapping, or are less significant than are portrayed on the maps.