ABAG Shaken Awake Report

	ABAG Shaken Awake! Report BACKGROUND

In 1992, ABAG estimated uninhabitable dwellings for future earthquakes affecting the San Francisco Bay Area with funding from the American Red Cross, the California Office of Emergency Services and ABAG itself. George Washington University (GWU) used these estimates in developing projections of shelter populations in future earthquakes in the San Francisco Bay Area.

The research which forms the basis for this document represents a significant refinement and expansion of previous efforts by ABAG and GWU. It incorporates more sophisticated ground shaking intensity models. In fact, those models were tested and refined using the loss estimation models developed for this project. It incorporates better data on the residential housing stock, including where it is located.
The Loma Prieta earthquake provided us with extremely valuable information. The residential structures tagged by local government building officials as unsafe (red) or limited access (yellow) following that earthquake have been carefully examined and analyzed. The data on daily occupancy load of Red Cross shelters were also examined.
Finally, we have been able to incorporate significant information from the Northridge earthquake in the Los Angeles area. GWU visited the Northridge area in early February 1994 to interview over 200 people in shelters or in line seeking other forms of housing assistance. GWU gathered valuable first-hand information on the demographic characteristics of those victims, as well as on the tagging of the housing which the victims had left, that is being incorporated into the Bay Area shelter model. ABAG project staff visited that area as well, traveling with a building inspector and on their own around the affected area to see first hand the damaged housing and the residential tagging process. ABAG also collected information on residential tagging from the local governments impacted in Northridge and spent days checking and refining the data provided. The ratios between green-, yellow-, and red-tagged housing units for different types of housing construction obtained from that southern California data were incorporated into the Bay Area model.
The research that formed a basis for this report had five principal objectives:

develop models of housing habitability based on intensity, distance from fault source, and underlying geologic materials for the San Francisco Bay Area;

model how shelter populations are related to structural damage, including data on buildings that are red-tagged as uninhabitable, as well as yellow-tagged as damaged based on actual Loma Prieta data;

assess the demographic characteristics of the shelter population versus the overall impacted population through use of the 1990 Census (conducted only five months after the earthquake) and Red Cross data from the Loma Prieta event;

relate the recovery time of the impacted housing stock to the structural type of those buildings for Loma Prieta; and

apply these lessons to future Bay Area earthquakes.

The goal of the project is to improve mitigation, disaster response and residential rebuilding efforts in future earthquakes. The project should help people plan for and rebuild faster after earthquakes.
The users of this information are varied:

relief agencies, such as the American Red Cross, for use in their shelter planning efforts;

local governments for (a) conducting vulnerability analyses (which, in turn, can be used for mitigation and emergency response planning); (b) pre-planning for quicker recovery of low-income housing stock; and (c) designing more effective programs to encourage owners to retrofit housing stock.

We firmly believe that modeling expected uninhabitable dwelling units and shelter needs using limited data is far superior to having potential users estimate these numbers themselves.
Given that the probability of a second major or catastrophic earthquake in the San Francisco Bay Area in the next ten years is one in three, the rapid dissemination of existing data and research is essential. Let's make sure that we aren't surprised by the next earthquake disaster.

ABAG, the Association of Bay Area Governments, is the regional planning and services agency for the nine-county San Francisco Bay Area.

This page was last updated 9/29/03 by jbp.

	develop models of housing habitability based on intensity, distance from fault source, and underlying geologic materials for the San Francisco Bay Area;
	model how shelter populations are related to structural damage, including data on buildings that are red-tagged as uninhabitable, as well as yellow-tagged as damaged based on actual Loma Prieta data;
	assess the demographic characteristics of the shelter population versus the overall impacted population through use of the 1990 Census (conducted only five months after the earthquake) and Red Cross data from the Loma Prieta event;
	relate the recovery time of the impacted housing stock to the structural type of those buildings for Loma Prieta; and
	apply these lessons to future Bay Area earthquakes.