Richard L. Bernknopf

Earthquake and volcano hazard notices: An economic evaluation of changes in risk perceptions

Abstract Earthquake and volcano hazard notices were issued for the Mammoth Lakes, California area by the U.S. Geological Survey under the authority granted by the Disaster Relief Act of 1974. The effects on investment, recretion visitation, and risk perceptionsare explored. The hazard notices did not affect recreation visitation, although investment was affected. A perceived loss in the market value of homes was documented. Risk perceptions were altered for property owners. Communication of the probability of an event over time would enhance hazard notices as a policy instrument and would mitigate unnecessary market perturbations.

A Portfolio Approach to Evaluating Natural Hazard Mitigation Policies: An Application to Lateral-Spread Ground Failure in Coastal California

In the past, efforts to prevent catastrophic losses from natural hazards have largely been undertaken by individual property owners based on site—specific evaluations of risks to particular buildings. Public efforts to assess community vulnerability and encourage mitigation have focused on either aggregating site—specific estimates or adopting standards based upon broad assumptions about regional risks. This paper develops an alternative, intermediate—scale approach to regional risk assessment and the evaluation of community mitigation policies. Properties are grouped into types with similar land uses and levels of hazard, and hypothetical community mitigation strategies for protecting these properties are modeled like investment portfolios. The portfolios consist of investments in mitigation against the risk to a community posed by a specific natural hazard. and are defined by a communitys mitigation budget and the proportion of the budget invested in locations of each type. The usefulness of this approach is demonstrated through an integrated assessment of earthquake—induced lateral—spread ground failure risk in the Watsonville, California area. Data from the magnitude 6.9 Loma Prieta earthquake of 1989 are used to model lateral—spread ground failure susceptibility. Earth science and economic data are combined and analyzed in a Geographic Information System (CIS). The portfolio model is then used to evaluate the benefits of mitigating the risk in different locations. Two mitigation policies, one that prioritizes mitigation by land use type and the other by hazard zone, are compared with a status quo policy of doing no further mitigation beyond that which already exists. The portfolio representing the hazard zone rule yields a higher expected return than the land use portfolio does; however, the hazard zone portfolio experiences a higher standard deviation. Therefore, neither portfolio is clearly preferred. The two mitigation policies both reduce expected losses and increase overall expected community wealth compared to the status quo policy.

Recovering from the ShakeOut Earthquake

Recovery from an earthquake like the M7.8 ShakeOut Scenario will be a major endeavor taking many years to complete. Hundreds of Southern California municipalities will be affected; most lack recovery plans or previous disaster experience. To support recovery planning this paper 1) extends the regional ShakeOut Scenario analysis into the recovery period using a recovery model, 2) localizes analyses to identify longer-term impacts and issues in two communities, and 3) considers the regional context of local recovery. Key community insights about preparing for post-disaster recovery include the need to: geographically diversify city procurement; set earthquake mitigation priorities for critical infrastructure (e.g., airport), plan to replace mobile homes with earthquake safety measures, consider post-earthquake redevelopment opportunities ahead of time, and develop post-disaster recovery management and governance structures. This work also showed that communities with minor damages are still sensitive to regional infrastructure damages and their potential long-term impacts on community recovery. This highlights the importance of community and infrastructure resilience strategies as well.

The influence of hazard models on GIS-based regional risk assessments and mitigation policies

Geographic information systems (GIS) are important tools for understanding and communicating the spatial distribution of risks associated with natural hazards in regional economies. We present a GIS-based decision support system (DSS) for assessing community vulnerability to natural hazards and evaluating potential mitigation policy outcomes. The Land Use Portfolio Modeler (LUPM) integrates earth science and socioeconomic information to predict the economic impacts of loss-reduction strategies. However, the potential use of such systems in decision making may be limited when multiple but conflicting interpretations of the hazard are available. To explore this problem, we conduct a policy comparison using the LUPM to test the sensitivity of three available assessments of earthquake-induced lateral-spread ground failure susceptibility in a coastal California community. We find that the uncertainty regarding the interpretation of the science inputs can influence the development and implementation of natural hazard management policies.

Mapping time-dependent changes in soil slip-debris flow probability

Risk of personal injury or property damage from rainfall-triggered debris-flow events can be expressed in terms of expected losses if the probability that a potentially hazardous event will occur can be combined with economic data about the value of property and infrastructure that could be lost from such an event. A realistic forecast of expected losses could provide an economic basis for community choices about whether, when, and how to impose regulations for mitigation (such as grading or land use constraints) and assign responsibilities for warning and hazard response. Experience in some landslide-prone communities where grading codes require preconstruction site studies has demonstrated that sufficiently detailed geotechnical studies can provide site-specific deterministic assessments of risks that can be reduced through mitigation (see, for example, Slosson and Krohn, 1982). However, because detailed site studies are relatively costly, geotechnical studies are not commonly made at sites where no significant financial commitment has already been made. Cost also commonly prohibits application of those methods to the kinds of regional assessments that are needed to support responsible decisions for community action. To be timely, regional risk assessments should take advantage of earth-science data (especially topographic, geologic, and soils maps) that already exist or can be acquired rapidly by reconnaissance techniques. To the extent that the elements of the map data are analogous to variables in established geotechnical models, their relations are expected to parallel those in the models; yet the use of existing regional map data and rainfall records from scattered gaging localities introduces greater uncertainty about spatial and temporal variations in earth materials and rainfall than is normally applied in geotechnical analyses of stability. Probability offers a means to characterize that uncertainty quantitatively. A map sequence that displays changes in the spatial distribution of probabilities provides a way to identify the areas of greatest hazard potential and a visual way to evaluate their relations to topographic or cultural features that may be in harms way. It has been a fairly common practice for regional data to be synthesized into qualitative susceptibility maps delineating, for example, map units of high, moderate, and low potential for hazard. The qualitative maps can be used by skilled professional planners to guide decisions about land use regulation. However, they cannot be applied directly to a quantitative economic assessment of risk, and maps made by different individuals and agencies for different areas may not be comparable even in a qualitative sense. Probability maps, which can be prepared by

The South Florida Ecosystem Portfolio Model: A Web-Enabled Multicriteria Land Use Planning Decision Support System

The South Florida Ecosystem Portfolio Model (EPM) prototype is a regional land use planning web tool that integrates ecological, economic, and social information and values of relevance to decision-makers and stakeholders. The EPM uses a multi-attribute evaluation framework that builds on GIS analysis and spatially-explicit models that characterize a wide array of important ecological, economic, and societal endpoints and consequences that are sensitive to regional land use/cover change. The EPM uses both monetized and non-monetized (multi-attribute utility) approaches to valuing these endpoints and consequences. By integrating a broad set of stakeholder values, from natural habitat preservation to storm surge concerns, the EPM allows on-line users to explore land use consequences and trade-offs that are often overlooked in public discourse. The EPM is designed to be used as an on-line decision support system for sustainable land use planning in South Florida. The EPM can be used directly by land use planning stakeholders or as part of a facilitated participatory decision process. The current prototype is implemented for Miami-Dade County, Florida.

Economic Assessment of the Use Value of Geospatial Information

Geospatial data inform decision makers. An economic model that involves application of spatial and temporal scientific, technical, and economic data in decision making is described. The value of information (VOI) contained in geospatial data is the difference between the net benefits (in present value terms) of a decision with and without the information. A range of technologies is used to collect and distribute geospatial data. These technical activities are linked to examples that show how the data can be applied in decision making, which is a cultural activity. The economic model for assessing the VOI in geospatial data for decision making is applied to three examples: (1) a retrospective model about environmental regulation of agrochemicals; (2) a prospective model about the impact and mitigation of earthquakes in urban areas; and (3) a prospective model about developing private–public geospatial information for an ecosystem services market. Each example demonstrates the potential value of geospatial information in a decision with uncertain information.

Improving the Homeland Security Advisory System: An Experimental Analysis of Threat Communication for National Security

This chapter describes how the Homeland Security Advisory System (HSAS) has become a key element of the government’s campaign against terrorism. The threat level is predominantly displayed on government websites, especially the Department of Homeland Security website, but also on those of many private agencies, including the Red Cross. The current HSAS threat level has been continuously displayed on the CNN/Headline News banner that is displayed at the bottom of the television screen. The system is not only intended to communicate timely and relevant information about security risks and terrorist threats it also contains information about precautions that agencies, businesses and members of the public can take against the threat. For fiscal year 2005, the administration is requesting an appropriation of

The southern California uplift and associated earthquakes

10 million to support the HSAS under a program of continual modification and improvement, while maintaining it as a sound component of homeland security.

An economic and geographic appraisal of a spatial natural hazard risk: a study of landslide mitigation rules

Southern California earthquakes ≥ M5.5 during the period 1955/01/01–1994/01/17 were concentrated along or adjacent to the south flank of the southern California uplift, as defined both at its culmination and following its partial collapse. Spatial clustering of these earthquakes within three more-or-less distinct groups suggests either gaps along the south flank that were previously filled or are yet to be filled. Nearly all of the indicated earthquakes accompanied or followed partial collapse of the uplift, and seismic activity within this regime seems to have been increasing through at least 1994/01/17.