Approved for public release; distribution is unlimited / This thesis formulates and solves a mixed-integer program to plan the recovery of an electrical power transmission grid that has been damaged by a natural disaster or terrorist attack. The damage can be extensive and recovery can take weeks or months. An efficient recovery plan that maximizes the utilization of repair resources can help ensure swift restoration of services. The network recovery-planning model is implemented in GAMS (General Algebraic Modeling System) and uses CPLEX as the solver. An electrical grid based on IEEE's 300-bus transmission network is used for testing. To simulate varying degrees of damage to the network, we choose up to 20% of the grid's lines, buses and transformers to be placed out of service. Based on the availability of repair resources, the repair-time horizon and penalties for unserved demand, the model produces a repair schedule that minimizes the cost of power shed. We demonstrate that for a network with up to 8% of its components damaged, the model can produce an optimal recovery plan within 20 minutes on a 2 GHz personal computer. For our largest test-case with 20% of network components damaged, the recovery plan is within 7% of optimal after 1 hour of solver time. / Outstanding Thesis

Global warming, which is one of the most serious consequence of climate change, can be expected to have different effects on the atmosphere, the ocean, icebergs, etc. Global warming has also brought secondary consequences into nature and human society directly. The most negative effect among the several effects of global warming is the rising sea level related to the large typhoons which can cause flooding on low-level land, coastal invasion, sea water flow into rivers and underground water, rising river level, and fluctuation of sea tides. It is crucial to recognize surge level and its return period more accurately to prevent loss of human life and property damage caused by typhoons. This study researches two topics. The first purpose of this study is to develop a statistical model to predict the return period of the storm surge water related to typhoon Maemi, 2003 in South Korea. To estimate the return period of the typhoon, clustered separated peaks-over-threshold simulation (CSPS) has been used and Weibull distribution is used for the peak storm surge height’s fitting. The estimated return period of typhoon Maemi’s peak total water level is 389.11 years (95% confidence interval 342.27 - 476.2 years). The second aim is related to the fragility curves with the loss data caused by typhoons. Although previous studies have developed various methods to mitigate damages from typhoons, the extent of financial loss has not been investigated enough. In this research, an insurance company provides their loss data caused by the wind speed of typhoon Maemi in 2003. The loss data is very important in evaluating the extent of the damages. In this study, the damage ratio in the loss dataset has been used as the main indicator to investigate the extent of the damages. The damage ratio is calculated by dividing the direct loss by the insured amount. In addition, this study investigates the fragility curves of properties to estimate the damage from typhoon Maemi in 2003. The damage ratios and storm induced wind speeds are used as the main factor for constructing fragility curves to predict the levels of damage of the properties. The geographical information system (GIS) has been applied to produce properties’ spatial wind speeds from the typhoon. With the damage ratios, wind speeds and GIS spatial data, this study constructs the fragility curves with four different damage levels (Level I - Level IV). The findings and results of this study can be basic new references for governments, the engineering industry, and the insurance industry to develop new polices and strategies to cope with climate change.

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Thesis (PhD (Civil Engineering))--Stellenbosch University, 1986. / ENGLISH ABSTRACT: This dissertation presents the development process of a wind damage and disaster management support model for South Africa. Several aspects of wind damage are analysed. The impact of wind disasters on human habitat is highlighted by providing selected data of loss due to such events. This is followed by a comprehensive review of relevant research, carried out locally and internationally. The role and relevance of wind loading codification is discussed. The factors influencing wind damage are identified and their applicability to South African conditions is evaluated. An outline of a database of wind damage in South Africa which has been developed during the course of the project is presented. Selected statistics derived from this database are presented. A probabilistic model for assessing wind damage in South Africa is proposed. The model is based on the spatial principle of occurrence of strong wind events. A 'first approximation' division of the country into zones where various types of wind events occur and the characteristics of their generic footprints (i.e. distribution of wind speeds) are developed. The risk model procedure also takes the distribution of wealth, and the vulnerability of the built environment into account. / AFRIKAANSE OPSOMMING: Hierdie verhandeling bied die ontwikkelingsproses vir 'n hulpmodel vir windskade en rampbestuur vir Suid-Afrika aan. Verskeie aspekte van windskade word ontleed. Die invloed van windskade op woongebiede word beklemtoon deur die aanbieding van geselekteerde data oor relevante plaaslike en internasionale navorsing. Die rol en toepaslikheid van windbelasting in ontwerpkodes word bespreek. Die faktore wat windskade beinvloed, word geidentifiseer en die aanwendbaarheid onder Suid-Afrikaanse omstandighede word beoordeel. 'n Beskrywing van n databasis vir windskade in Suid'-Afrika, wat tydens die projek saamgestel is, word aangebied. Sekere statistiek wat uit die databasis afgelei is, word voorgelê. n Statistiese model vir die beraming van windskade in Suid-Afrika word voorgestel. Die model is gebaseer op die ruimtelike beginsel van voorkoms van sterk-wind-gebeurlikhede. 'n "Eerste benadering" - indeling van die land in streke waar verskillende soorte windgebeurlikhede voorkom en hulle karakteristieke kenmerke (bv. verspreiding van windspoed) is ontwikkel. Die werkwyse vir die risikomodel neem die verdeling van rykdom en die kwesbaarheid van die beboude omgewing in ag.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, February 2015. / Due to its geographical location, poor economic situation and geological features that are characterised by mostly mountainous terrain, Lesotho is vulnerable to hazardous events associated with climate, such as drought, floods, heavy snow, and severe frost. This research explores factors underlying spatial vulnerability of places to natural hazards in south-western Lesotho. Prior vulnerability assessments in Lesotho have investigated vulnerability in terms of identifying populations that are most food insecure and vulnerable to hunger. By broadening the scope of vulnerability to include biophysical and socioeconomic characteristics, the study emphasises the concept of place vulnerability as a foundation for understanding Lesotho’s vulnerability to natural hazards. Spatial orientation of vulnerability within a geographical area provides an easy way for planners and decision makers to identify areas that may require additional resources in order to prepare for disasters. To date, no quantitatively based vulnerability assessment has been undertaken in Lesotho, so this study is one of the first to assess place vulnerability to natural hazards in Lesotho using GIS and it emphasise the role of geography of a place.

Since 2004 there have been multiple devastating tsunamis around the globe triggered by large magnitude earthquakes; with the most recent being the Tohoku, Japan tsunami in March 2011. These tsunamis have caused significant loss of life and damage to the coastal communities impacted by these powerful waves. The resulting devastation has raised awareness of the dangers of tsunamis and the Network for Earthquake Engineering Simulation (NEES) housesmash project (NEEShousesmash), was started to investigate several different areas of tsunami inundation. The work presented in the following two manuscripts was performed at the O.H. Hinsdale Wave Lab and Gene D. Knudson Wood Engineering Lab, which are located at Oregon State University. This work represents a small portion of the total NEEShousesmash project, and is focused on improving the knowledge and predictability of tsunami loading and structural performance. The first manuscript investigates tsunami wave impact on full scale light-frame wood walls, and compares the measured forces to calculated values using the linear momentum equation, previously evaluated by Cross (1967). The results show for each wave height tested a peak transient force followed by a sustained quasi-static force, with a ratio of transient force to quasi-static force of 2.2. The results also show that the linear momentum equation did an acceptable job of predicting the measured transient forces on the walls to within ±10%, and that increased wall flexibility, 2x4 vs. 2x6 dimensional lumber, resulted in lower measured transient forces when subjected to similar tsunami wave heights. These results are important for practical use because the linear momentum equation is a simple equation to use, that only requires a couple of site specific input variables. The second manuscript is a continuation of the work done in the wave lab for the first manuscript. These experiments provide a starting point for expanding the testing of the structural response and performance of larger scale structures subjected to tsunami wave loads. By simulating tsunami loading in a traditional structures laboratory, the inherent limits of testing structural performance in small scale tsunami laboratory facilities is removed. The results show that a light-frame wood shear wall, built to current standards, is susceptible to premature failures from concentrated impact loads at intermediate heights compared to the design strength at full height. It is also shown that the out-of-plane walls subjected to both elastic and inelastic loads behave like a one way slab with minimal load sharing between adjacent studs. The failures observed during the hydrodynamic wave testing of the nailed connection between the bottom plate and studs was successfully reproduced, and shows that current construction standards are not fully utilizing the available capacity of each stud when subjected to tsunami waves. The reinforcement of this connection with traditional metal brackets would help increase the capacity of the out-of-plane wall to resist tsunami wave loads. / Graduation date: 2012