Urban Flood Vulnerability Assessment Using the Entropy Weight Method

Abstract

Locally concentrated heavy rainfall has led to an increase in the occurrence of flood damage. This is especially so in the urban areas, which are relatively more vulnerable to flood damage due to the high population and property density. In Seoul, which has 25 administrative districts, heavy rainfall triggered flood-related damage in 2010, 2011, and 2018. However, the flood characteristics of each district were different due to difference in flood impact factors such as topography, weather, and disaster prevention measures. The flood vulnerability of each district should be assessed based on local characteristics to reduce flood damage. This study collected and calculated 15 characteristic data points that can explain the climate exposure, sensitivity, and adaptive capacity of each district using the entropy weight method. Thereafter, the flood vulnerability of each district was calculated based on climate exposure, sensitivity, and adaptive capacity, using the Euclidean method. The results showed that the northern and western areas in Seoul are highly vulnerable due to high climate exposure, sensitivity, and low adaptive capacity. In contrast, the other parts of Seoul had low vulnerability due to high sensitivity, low climate exposure, and high adaptive capacity. These results will contribute to the establishment of a flood damage reduction plan that reflects local characteristics.