Improved Seismic Monitoring Improved Decision Making

Improved Seismic Monitoringâ€"Improved Decision-Making, describes and assesses the varied economic benefits potentially derived from modernizing and expanding seismic monitoring activities in the United States. These benefits include more effective loss avoidance regulations and strategies, improved understanding of earthquake processes, better engineering design, more effective hazard mitigation strategies, and improved emergency response and recovery. The economic principles that must be applied to determine potential benefits are reviewed and the report concludes that although there is insufficient information available at present to fully quantify all the potential benefits, the annual dollar costs for improved seismic monitoring are in the tens of millions and the potential annual dollar benefits are in the hundreds of millions.

Quantifying the social and economic value that geospatial information contributes to modern society is a complex task. To construct reliable and consistent valuation measures requires an understanding of the sequence of processes that starts with data acquisition, and leads to decision-makers’ choices that impact society. GEOValue explores each step in this complex value chain from the viewpoint of domain experts spanning disciplines that range from the technical side of data acquisition and management to the social sciences that provide the framework to assess the benefit to society. The book is intended to provide foundational understanding of the techniques and complexities of each step in the process. As such it is intended to be assessable to a reader without prior training in data acquisition systems, information systems, or valuation methods. In addition, a number of case studies are provided that demonstrate the use of geospatial information as a critical input for evaluation of policy pertaining to a wide range of application areas, such as agricultural and environmental policy, natural catastrophes, e-government and transportation systems.

The United States will certainly be subject to damaging earthquakes in the future. Some of these earthquakes will occur in highly populated and vulnerable areas. Coping with moderate earthquakes is not a reliable indicator of preparedness for a major earthquake in a populated area. The recent, disastrous, magnitude-9 earthquake that struck northern Japan demonstrates the threat that earthquakes pose. Moreover, the cascading nature of impacts-the earthquake causing a tsunami, cutting electrical power supplies, and stopping the pumps needed to cool nuclear reactors-demonstrates the potential complexity of an earthquake disaster. Such compound disasters can strike any earthquake-prone populated area. National Earthquake Resilience presents a roadmap for increasing our national resilience to earthquakes. The National Earthquake Hazards Reduction Program (NEHRP) is the multi-agency program mandated by Congress to undertake activities to reduce the effects of future earthquakes in the United States. The National Institute of Standards and Technology (NIST)-the lead NEHRP agency-commissioned the National Research Council (NRC) to develop a roadmap for earthquake hazard and risk reduction in the United States that would be based on the goals and objectives for achieving national earthquake resilience described in the 2008 NEHRP Strategic Plan. National Earthquake Resilience does this by assessing the activities and costs that would be required for the nation to achieve earthquake resilience in 20 years. National Earthquake Resilience interprets resilience broadly to incorporate engineering/science (physical), social/economic (behavioral), and institutional (governing) dimensions. Resilience encompasses both pre-disaster preparedness activities and post-disaster response. In combination, these will enhance the robustness of communities in all earthquake-vulnerable regions of our nation so that they can function adequately following damaging earthquakes. While National Earthquake Resilience is written primarily for the NEHRP, it also speaks to a broader audience of policy makers, earth scientists, and emergency managers.

Earthquakes in the last 100 years have resulted in $3 trillion U.S. dollars in economic losses worldwide. Even moderate-magnitude events, such as the Mw6.7 1994 Northridge earthquake and the Mw6.9 1989 Loma Prieta earthquake, have caused widespread damage, significant economic losses, and tens of thousands of families displaced from their homes. In the last two decades, the performance-based earthquake engineering framework developed by the Pacific Earthquake Engineering Research Center, also referred to as the PEER PBEE framework, has gained much attention from researchers and practitioners not only in the U.S. but also in most seismic-prone countries. This framework was focused on individual structures under seismic hazards. However, large earthquakes occurring close to large urban regions may strike and affect thousands or even millions of structures simultaneously, leading to large numbers of casualties and significant disruptions to the normal functionality of communities. Hence, the concept of "performance" in PBEE needs to be expanded from an individual to a regional scale, with broader definitions of stakeholders and performance metrics in order to evaluate the seismic risk of groups of structures that are spatially distributed within a region, referred to as regional seismic risk. The main goal of this dissertation is to propose improved regional seismic risk methodologies within a probabilistic framework that explicitly quantifies, incorporates, and propagates uncertainties at the different stages of the analysis, in order to provide improved information for decision makers. The main contributions of this dissertation are: • A mathematical formalization of a regional performance-based earthquake engineering (RPBEE) framework for seismic risk assessment of groups of structures and infrastructure spatially distributed within a region. • An improved model for the spatial correlation of ground motion intensity measures, which is based on 39 well-recorded earthquakes and is the first model that explicitly incorporates the event-to-event variability. • Recommendations of ground motion intensity measures to characterize the seismic hazard for regional seismic risk assessment of wood-frame single-family houses. • An investigation on the relative seismic performance of one- and two-story houses, leading to recommendations for future building classification systems for regional seismic risk assessment, where one- and two-story houses are separated into different classes with different seismic vulnerabilities. • Novel fragility curves for estimating the probability of damage to chimneys and severe damage to structural shear walls in wood-frame single-family houses which are particularly useful for improving current approaches to estimate the number of yellow- and red-tagged wood-frame single-family houses. • A model for explicitly incorporating the correlation between the damage in different structures conditioned on their ground motion intensities for regional seismic risk asessment, along with an investigation on the effect of this correlation on regional seismic risk metrics. • A probabilistic framework for evaluating and comparing alternative public policies for enhancing the seismic performance of structures in terms of regional seismic risk mitigation. • Evaluation of the inherent regional risk of collapse implicit with the probability of collapse of individual buildings that is currently specified as acceptable in U.S. seismic design provisions. • A simplified seismic design approach that explicitly considers the regional seismic risk in the seismic design criteria of structures, referred to as "regional-risk-targeted seismic design.".