Determining flood risk vulnerability using factor analysis approach

Abstract

Floods are becoming a frequent natural disaster in Sri Lanka. Although it is an uncontrollable natural event, it is essential to pay attention in necessary policy making in order to control floods in the future. Therefore, this study targets to develop a framework to identify the high risk areas in Sri Lanka. This provides useful information to the government as well as the policymakers to take necessary preparedness, prevention, and awareness actions to lessen the risk from floods. This study uses principal component analysis (PCA) to explore the flood situation in Sri Lanka and to rank the main regions according to the risk level by considering flood risk and controlling factors. Twelve factors including both flood risk and controlling indicators are identified based on prior literatures and then the original data set is constructed. With the aid of the PCA method, four principal components are identified, and they are human induced factor, natural induced factor, human induced controlling factor, and natural induced controlling factor. Based on the weights of the principal components a comprehensive score is derived. Finally, the main regions are ranked using the comprehensive scores. The results reveal that Rathnapura, Kalutara, Colombo, Kurunegala and Matara regions have a high-risk chance of having floods.