An Investigation of the Adequacy of Urban Evacuation Centers Using Index-based Flood Risk Assessment

With frequent intense flood events in recent years, reliable flood risk assessment has become a critical component of flood mitigation. This research aims to assess the adequacy of pre-determined evacuation centers using a multi-criteria flood risk map that considers urban-specific indicators such as physical, social, economic, and environmental criteria. The analytical hierarchy process (AHP) was used as the multi-criteria decision technique for calculating the weight of each criterion. These criteria weights were used to spatially map the flood risk index using an overlay function in a geographic information system (GIS), with the flood risk index divided into seven categories ranging from very low risk to very high risk. Then, 202 pre-determined evacuation centers from the Disaster Response Operations Monitoring and Information Center (DROMIC) were plotted on the developed flood risk map. Very high risk areas were found mostly in the City of Manila. This could be attributed to its very high exposure index values. The highest number of evacuation centers were found at Valenzuela where flood risk ranges from moderately low risk to moderate high risk. Only two evacuation centers were declared within Quezon City where flood risk ranges from very low risk to moderately high risk. Remarkably, there were no declared evacuation centers in Pasig and Pateros. The approach in this study is merely one of several flood risk assessment applications. Results from this study can assist the government agencies responsible in assessing the sufficiency and reliability of pre-determined evacuation centers.