A Simplified Urban Waterlogging Risk Assessment Framework: A Case Study of Nanning City

Abstract

Urban waterlogging poses an increasing challenge due to global climate change and rapid urbanization. Applicable urban waterlogging risk assessment models are essential to improve community-wide participatory waterlogging mitigation and adaptation strategies. This study introduces a simplified Urban Waterlogging Risk Assessment Framework(U-WRAF) designed to overcome the high technical thresholds and heavy data demands common in existing urban waterlogging risk assessment studies. Using the city of Nanning as a case study, the study analyzes the urban waterlogging risk and estimates the direct economic value impacted by urban waterlogging in Nanning in 2022 by integrating Multi-Criteria Decision Analysis (MCDA) and Geographic Information System (GIS) with publicly available geographic, hydrological, and socio-economic data. The results show that the direct economic loss value of urban waterlogging in Nanning in 2022 amount to RMB 780 million, equivalent to 0.15% of the city’s annual gross domestic product (GDP). These findings highlight the urgent need to strengthen effective urban waterlogging management in Nanning. The main contributions of this study are to offer an accessible, low-cost assessment method for engaging a wide range of stakeholders in the improvement of urban waterlogging risk prevention strategies and to provide valuable preliminary analyses and suggestions for the improvement of urban waterlogging management systems.