A comprehensive analysis method of spatial prioritization for urban flood management based on source tracking

Abstract

Flooding is one of the most frequent and disastrous natural hazards that can have catastrophic impacts on human society and urban infrastructure. Increasing the incidence of urban flooding highlights the need for reliable flood mitigation strategies that can effectively minimize losses owing to disasters. The strategic placement of flood mitigation measures is undoubtedly the key to achieving maximum effectiveness of flood reduction schemes. The physical characteristics of the site and knowledge of regional relevance play an important role in determining the location of appropriate flood mitigation measures. In the case of limited resources, it is crucial to prioritize areas for installation of flood mitigation measures. Therefore, an indicator-based method was developed in this study to identify and prioritize sites to concentrate limited resources where they are needed the most. Based on the source tracking method, a tracer-aided urban flood model was developed to study the impact of direct and indirect connections between urban systems, explore their relative importance in the network, and prioritize related risks to improve resource allocation efficiency. Longkungou drainage district of Haikou City was selected as the study area to determine the prioritization of catchments for flood mitigation. The results indicated that high prioritization sites are in the upstream of the urban areas with prioritization decreasing downstream, and the prioritization of interventions presents a spatial trend of “high south and low north”. This study demonstrates the novelty of a tracer-aided urban flood model in flood management and highlights the spatial connectivity between flood source areas and flood hazard areas. The prioritization scheme of urban catchment flood mitigation measures proposed in this study provides valuable guidance for policy makers and urban planners who wish to exploit the approach for flood mitigation.