Urban debris flow vulnerability map: An application to the metropolitan cities in Korea

Abstract

This study is a follow-up study of Park et al. [1] and aims to produce urban debris flow vulnerability maps of metropolitan cities in Korea. While the previous study has limitations that can assess the relative vulnerability of a single city, this study is possible to compare and assess the urban debris flow vulnerability of many metropolises. Target areas are Busan, Daegu, Daejeon, Gwangju, Incheon, Seoul, and Ulsan. The vulnerability of metropolitan cities is evaluated with the same criteria and is represented by using a single index value. The vulnerability is classified into five classes (most vulnerable, more vulnerable, moderate, less vulnerable, and least vulnerable) by using the Jenks optimal algorithm. Finally, urban debris flow vulnerability maps for seven metropolises are produced, and the relative vulnerability assessment is performed between each of metropolises. Also, this study investigated the influences of physical vulnerability and socioeconomic vulnerability through clustering of debris flow disaster vulnerability grades. Its result can be used to decide policy direction for debris flow prevention measures. When the physical vulnerability is relatively high and socioeconomic vulnerability is relatively low such as vulnerability assessment results of Seoul, the disaster prevention project reducing the damage of debris flow disasters should be preferentially carried out for the structural measures. On the other hand, if the physical vulnerability is relatively low and socioeconomic vulnerability is relatively high, non-structural measures should be performed to reduce the damage of debris flow disasters.