Permafrost Settlement Caused By Climate Warming In Alaska And The Estimation Of Its Damage Costs For Public Infrastructure

Abstract

Climate models and studies indicate that the changes in the northern latitudes will be serious and accelerated. Climate warming may impact structures in the northern latitudes through permafrost settlement affecting the performance of infrastructure and increasing costs for maintenance. The material presented is organized in three main chapters. Chapter 1 describes the motivation for the research. Chapter 2 addresses the permafrost settlement hazard in Alaska. I developed the Permafrost Settlement Hazard Index, which considered anticipated climate warming and ecological characteristics which regulate permafrost settlement. I found that the discontinuous permafrost region is at more risk due to permafrost settlement than other regions of Alaska. I also found that the correlation that the areas with high settlement hazard value have higher road maintenance costs. Chapter 3 is an estimate of damage cost caused by permafrost settlement related to climate warming in the field of public infrastructure. I concluded that climate warming may add about $106 million annually from 2010 to 2050 to annual costs for public infrastructure in Alaska. This amount of damage cost is the relative size of damage cost that is caused by climate warming. In order to understand the broader idea of adaptation methods, a case study of Alaska roads for discontinuous permafrost regions is presented in Chapter 4. Some alternative construction methods were chosen as adaptation methods. Then, the comparison of the cost effectiveness of each adaptation method was shown to identify the most economical option when the cost estimation includes the effect of the additional permafrost settlement caused by climate warming. I concluded that pre-thaw method was the most cost effective method. I also recommended Air-Cooled Embankment on a condition that coarse rocks are available to create a convection cell. Chapter 5 summarizes the research and indicates possibilities for future research directions. I employed an interdisciplinary approach combining engineering knowledge with environmental impact assessments, utilizing economic tools in estimating damage costs, and analyzing the cost effectiveness of adaptation options to climate induced permafrost settlement. Nevertheless, this interdisciplinary analysis was not intended as a civil engineer design but intended for these economic estimates.