Characterizing poqer systems for seismic response or risk analysis

Power systems are complex networks that have a high degree of redundancy incorporated into their designs to improve system reliability. The redundancy includes multiple circuits that use diverse routes on the transmission and sub-transmission systems between nodes, and also incorporates redundancy into the design of systerm nodes, that is, its substations. A method is presented for modeling power systems to assess their response that takes into account both levels of redundancy. The methodology accommodates different levels of detail to describe the network to meet different application needs. The methodology can be used to estimate direct losses and the extent and duration of disruption from scenario earthquakes. To determine the duration of disruption, the restoration process must be characterized and must include realistic methods used by utilities to restore service under emergency conditions. The focus of the paper is on formulating generic substation models based on data used by utilities for load flow analysis combined with limited description of design practices provided by utilities. The importance of including local soil effects on substation perfomance in fragility estimates is dicussed.(AU)

Watershed fires - The making of mutant floods

While the Stafford Act clearly "encourages hazard mitigation," as noted above, there are many impediments in the process that in fact discourage mitigation. As we find ourselves arguing about eligibility, it is really the level of assistance that is being debated. How much is enough, and who should pay for it? We are thus joined with the debate of "cost containment" versus "cost benefit," and what the federal role should be

Flood control and habitat preservation in the Mojave River, Victorville, California

Victorville, California, was flooded during January and February 1993. Floodwater overtopped and eroded levees. Homes and streets were inundated, highway access ramps were closed, and interstate bridge spread footings were undermined by erosive return flows. Public and private damage totalled about $1.6 million. The Mojave River flows northward across 140 miles of desert from the San Bernardino Mountains to Soda Dry Lake (near Baker, California). The upper watershed receives over 40 inches of mean annual precipitation while the lower watershed receives only about 3 inches. Although the river is ephemeral, there is some perennial bedrock flow and continuous subsurface flow. Existing flood control structures include levees composed of sand reinforced by pile and wire revetment, and highway and railroad guide levees constructed to higher design standards. The 8000-ft study reach near Victorville is divided by the I-15 bridge. The upper half is primarily urban, containing homes, businesses and a campground; the lower half is primarily open space with some isolated agriculture and recreation

Government's role in natural hazard reduction : Innovation in California approach

The powers, responsibilities and resources of government and limited. The traditional parading defining that government should 1) through regulation, prevent the individual's exposure to risk; 2) through public safety agencies, be responsible for disaster response; 3) through relief and insurance, indennifity the individual against loss; and 4)through post disaster government loans and grants, make the individual and communitywhole, is no longer valid. A new paradigm is necessary, one that recognizes the limits of government and the responsibility of the individual and the community to reduce their exposure to hazards. This paper will describe the experience of the State of California in reevaluating where government intervention is most appropriate and where it can be most effective (AU)

Chapter 4 : Post-earthquake shelter and housing : Research findings and policy implications

This chapter presents an overview of shelter and housing as social processes following disasters. it begings with a review of basic concepts used to describe the various types of shelter and housing and defines problem areas in the delivery of various types of post-disaster shelters. Three case studies are presented from recent earthquakes in California including the 1983 Coalinga earthquake, the 1987 Whittier-Narrows earthquake, and the 1989 Loma Prieta earthquake. These case studies are used to identify current issues and problems in sheltering and housing disaster victims, particularly as they concern a demographically diverse multicultural population. The potential shelter and housing problems after a New Madrid Seismic Zone earthquake are discussed in light of these three case histories and provide the basis for planning shelter and housing programs in the Central United States.(AU)

Population and housing in the special studies zones

The alquist-Priolo Special studies zones were defined to encompass areas in California containing active or potentially active earthquake fault traces. This paper analyzes the population and housing composition of these areas, comparing and contrasting special studies zones residents with the general population of California with respect to economic, ethnic, and demographic characteristics. Three major findings emerge : first, the zone are racially, ethnically and economically diverse, second, the population in the zones is slightly wealthier and includes more white persons than California as a whole; and third, the housing is slightly newer and larger. It is argued that the findings have important implications for a geologically differentiated lendig policy (AU)