Overcoming Public and Political Challenges for Natural Hazard Risk Investment Decisions

The cost of natural disasters continues to rise around the world, in part due to the direct and indirect effects of population growth, urbanization, and the pressures they place on land use. To reduce the vulnerability of infrastructure, especially existing infrastructure, will require that engineers bring more than technical capabilities to bear. Engineers also need to know which measures of risk are most meaningful or relevant to decision makers, and then be able to communicate those risks, and the costs and benefits of mitigation, in concise, credible, meaningful terms. A major challenge in developing a plan to retrofit under-designed structures is demonstrating a need to the public and their political leaders, who may have difficulty extrapolating un-experienced low-probability, high consequence events. Many issues must be addressed which all play a role in the tension between short-term rewards to decisions and longterm sustainable actions. Review of current knowledge along with a reassessment offering new understanding and communication tools will be presented focusing on the issues of: (1) public risk perception, (2) public participation in hazard mitigation planning, (3) incorporation of community values, (4) incompatibility of political motivation and long-term planning, and (5) finances of risk and return. A case study reviewing the work done by the San Francisco Community Action Plan for Seismic Safety (CAPSS) team will be presented as an example that effectively implements methods presented in this thesis

A First-Order Reliability Approach to Building Portfolio Loss Estimation and Mitigation Prioritization

The prediction of future losses from earthquake events and other natural hazards is of importance to community developers, insurance entities, political organizations and many others in hazard-prone regions. Often, this risk assessment is preferred at a regional level as many private and public entities are concerned with the impact of an earthquake on a suite of buildings, as opposed to that for a single site. Assessing risk at a regional level is more complicated than doing so for individual sites due to the correlation that exists between the performances of spatially distributed buildings within a single hazard. This spatial correlation has been shown to be vital for characterizing potential loss at a regional level; however, it is often neglected in existing loss estimation methodologies.This dissertation proposes the use of the First-Order Reliability Method (FORM) to quantify probabilistic losses to a portfolio while incorporating the spatial correlation that exists between building performances. FORM is an approximate, analytical structural reliability technique that computes failure probability based on a linearization of a performance limit state. Unlike existing loss estimation tools that evaluate loss based on expected values or with the use of simulation, the proposed method evaluates the distribution of potential losses analytically and is also computationally efficient. In addition, sensitivity measures are computed using FORM to prioritize cost-effective retrofit strategies within a building portfolio. This proposed method is applied to a selected San Francisco building inventory to estimate total structural and nonstructural repair cost in the form of loss exceedance curves. Sensitivity measures are used to prioritize building types that yield the most reduction in regional risk per dollar of retrofit. In additional to quantifying losses, the proposed framework is extended to assess the seismic resilience for the San Francisco building portfolio. Sensitivity measures are computed relative to changes in system resilience for each dollar allocated to pre-disaster retrofit and to increasing post-disaster restoration efficiency. Finally, the study also investigates the extension of the proposed FORM-based approach to assess the cumulative hazard-induced risk for regions subjected to multiple hazards. In this extended study, FORM is used to compute the distribution of loss for Charleston County, South Carolina, specific to potential earthquake and hurricane wind hazards. The proposed approach provides an analytical and efficient tool for quantifying hazard risk at a regional level. By more effectively quantifying hazard-induced loss, resilience and sensitivities within a portfolio system, information is provided to improve hazard risk assessments and support more efficient risk management decision making

Feasibility study for a numerical aerodynamic simulation facility. Volume 1

A Numerical Aerodynamic Simulation Facility (NASF) was designed for the simulation of fluid flow around three-dimensional bodies, both in wind tunnel environments and in free space. The application of numerical simulation to this field of endeavor promised to yield economies in aerodynamic and aircraft body designs. A model for a NASF/FMP (Flow Model Processor) ensemble using a possible approach to meeting NASF goals is presented. The computer hardware and software are presented, along with the entire design and performance analysis and evaluation

Physical controls on water migration in above ground elemental sulphur blocks

Elemental sulphur (S0) is produced from processing bitumen from the oil sands region, Alberta. Long term storage of this S0 is under consideration. The objective of the current study was to determine the controls on water migration in variably saturated S0 blocks. Based on visual observations of S0 blocks, they were characterized as a hydrophobic fractured porous media. Thus, measurements of the hydraulic characteristics, including porosity (n) and hydraulic conductivity (K) of the matrix and the fractured media, were undertaken. These data were used to create characteristic relationships of unsaturated K (Kunsat) and volumetric moisture content (è) change with change in positive injection pressure (Ø).Analyses showed that the mean total matrix n (nm) was 0.094 ± 0.035 (n = 280), the mean n available for water migration (na) was 0.065 ± 0.044 (n = 8) and the mean (geometric) K for the matrix was 2.0 x 10-6 ± 2.1 x 10-6 ms-1. In the case of vertical fractures, the aperture frequencies were measured to be 2.5, 10.0 and 21.0 m-1 for fractures with apertures > 1.4, 1.4 to 0.6 and 1.4, and < 1.4 mm respectively. The fracture n (nf) was determined to be 0.0135. è – Ø relationships were determined for both the fractured and non fractured media. From these plots, water entry values of 9 mm and 1 m were determined for the fracture pore space and the matrix pore space, respectively.Simulations of packer tests resulted in a bulk saturated K (Kb) values ranging from 8.5 x 10-5 to 2 x 10-4 ms-1 above 9 m depth and 3 x 10-6 to 1.5 x 10-5 ms-1 below 9 m depth. Coupled Kunsat – Ø and è – Ø relationships were used to conceptually describe water migration in S0 blocks under different precipitation and mounding conditions. These plots also showed that the Kb is dominated by the fractures

Journal of Integrated Disaster Risk Management Overcoming Public and Political Challenges for Natural Hazard Risk Investment Decisions

Abstract The cost of natural disasters continues to rise around the world, in part because of population growth, urbanization, and the pressures they place on land use. To reduce the vulnerability of infrastructure, especially existing infrastructure, will require that engineers bring more than technical capabilities to bear. Engineers need to know which measures of risk are most meaningful or relevant to decision makers and then be able to communicate those risks and the costs and benefits of mitigation in concise, credible, meaningful terms. A major challenge in developing a plan to retrofit weaker structures is demonstrating a need to the public and its political leaders, who may have difficulty extrapolating personal experiences to low-probability, high-consequence events. Review of recent research and examination of case studies has led to the identification of five key issues that seem central to effective risk and retrofit communication: (1) public risk perception, (2) public participation in hazard mitigation planning, (3) incorporation of community values, (4) incompatibility of political motivation and longterm planning, and (5) finances of risk and return. These issues provide a framework for understanding the challenges to promoting retrofit and for developing communication strategies to overcome these challenges. The resulting risk-communication strategies can be used to improve long-term sustainable policy with recognizable benefits to society. The San Francisco Community Action Plan for Seismic Safety (CAPSS) team is presented as a case study that effectively addresses the issues identified here

Preliminary extension of First Order Reliability Methods for combined seismic and wind hazard loss estimation for a portfolio of buildings

In this paper, an initial analysis is performed to assess the potential loss to a building portfolio subjected to multiple, independent hazards. The procedure extends prior research that uses the First Order Reliability Method (FORM) to analyze the vulnerability of a portfolio of buildings to a seismic hazard. The paper includes discussion of issues to consider for community-wide damage measures and dependencies. The results are applied to Charleston, South Carolina, a community that has both seismic and hurricane hazards.Non UBCUnreviewedThis collection contains the proceedings of ICASP12, the 12th International Conference on Applications of Statistics and Probability in Civil Engineering held in Vancouver, Canada on July 12-15, 2015. Abstracts were peer-reviewed and authors of accepted abstracts were invited to submit full papers. Also full papers were peer reviewed. The editor for this collection is Professor Terje Haukaas, Department of Civil Engineering, UBC Vancouver.Facult