Development and application of a methodology for vulnerability assessment of climate change in coastal cities

This research is based on the need to develop methodology for climate change vulnerability assessment in coastal cities. While there have been some studies on the development of methodologies for vulnerability assessment on a national scale, there have been few attempts to develop a method for local vulnerability assessment with application to coastal cities. The objective of this study was to develop a general methodology to assess vulnerability to climate change and to apply it to the metropolitan coastal city of Busan in South Korea. We followed the conceptual framework for assessing climate change vulnerability provided by the Intergovernmental Panel on Climate Change (IPCC), which is composed of climate exposure, sensitivity, and adaptive capacity. Sea level rises of 0.5 m, 1 m, 2 m, and 3 m were considered as the climate exposure. Sensitivity to sea level rise was measured based on the percentage of flooded area calculated using flood simulation with a GIS tool. The population density and the population at age 65 years and over were also included in the calculation of sensitivity index. Sensitivities to heat wave and heavy rainstorm were quantified using the expert opinions from the Delphi survey and information on land use classification. Adaptive capacity was assessed in three sections: economic capability, infrastructure, and institutional capabilities. By combining the adaptive capacity and three different sensitivities, vulnerability to sea level rise (SLR-V), vulnerability to heavy rainstorm (HR-V), and vulnerability to heat wave (HW-V) were separately evaluated in 16 counties of Busan. Using cluster analysis, we could classify four major groups of counties based on SLR-V, HR-V, HW-V, and reported damage cost. For clustered groups, different adaptation strategies were suggested based on the different vulnerability patterns. Application of our methodology to Busan indicated that our methodology is easy to use and provides concrete policy implications when setting up adaptation strategies. The methodology developed in this study could also be used in mainstreaming climate change into Integrated Coastal Management (ICM).