Abstract:Zhengzhou, a pivotal city in the Central Plains region, witnesses rapid urban development, accompanied by swift transformations in its urban underlying surfaces, exposure levels, and spatial distribution of precipitation patterns. As a result, urban waterlogging incidents become a frequent occurrence, posing significant challenges to the city’s resilience. Recognising this, it becomes imperative to conduct a scientific and objective assessment of the risk of urban waterlogging disasters. This assessment seeks to establish a robust scientific basis and foundation that can inform urban flood control strategies, guide disaster risk management practices, and facilitate the planning and development of sponge city initiatives in Zhengzhou. To comprehensively evaluate the risk of urban waterlogging in Zhengzhou’s central urban area, this study adopts a method that integrates the CRITIC (Criteria Importance Through Intercriteria Correlation) objective weighting technique with the AHP (Analytic Hierarchy Process). This combined approach leverages the mechanism of urban waterlogging disasters and incorporates relevant data such as terrain features, precipitation patterns in recent years, and the latest economic development indicators. By applying this rigorous method, the study aims to provide a nuanced understanding of the risk of rainstorm waterlogging in the study area. The results show that the high and secondary high-risk areas of urban waterlogging disasters in Zhengzhou’s central urban area are primarily concentrated in Erqi District, the northwest and eastern regions of Guancheng District, and the southern part of Jinshui District. Notably, Erqi District exhibits the highest average disaster-causing risk index among all districts, reaching the level of secondary high risk. In contrast, Guancheng District and Jinshui District exhibit an average risk level that is moderate. To validate the robustness of the assessment results, major waterlogging events in recent years are analysed for verification. The analysis demonstrates that 44.2% of the waterlogging points are located within the high and secondary high-risk areas of waterlogging, while 77.3% are situated in areas with risks above the moderate level. Furthermore, through detailed case analysis, it is observed that the majority of waterlogging points during the waterlogging process align closely with the moderate and high-risk areas of urban waterlogging, indicating a high degree of accuracy and reliability in the assessment method. The evaluation results presented in this study effectively reflect the distribution of waterlogging disaster risks in Zhengzhou’s central urban area. Specifically, in Erqi District, the northwest of Guancheng District, and the south of Jinshui District, where waterlogging points are concentrated and exhibit the highest density, the risk levels are consistent with the secondary high risk and above of waterlogging disasters. This strong correlation between the assessment results and actual waterlogging incidents underscores the reliability and validity of the assessment method used in this study. Consequently, these findings can provide valuable insights and guidance for urban flood control strategies, disaster risk management practices, and the planning and development of sponge city initiatives in Zhengzhou.
