重庆市沙坪坝区内涝风险评估

Assessment of Urban Waterlogging Risk in Shapingba District of Chongqing

摘要:

以重庆市沙坪坝区为研究区域，针对山地城市内涝风险的空间异质性与动态演化特征，构建了包含危险性、暴露度和脆弱性的综合评估体系。采用层次分析法（AHP）与熵权法相结合的主客观赋权方法，量化分析了降雨强度、高程、坡度、人口密度、路网密度等 8 项指标的权重。研究发现，降雨强度（综合权重0.32）高程（0.12）和坡度（0.13）是影响内涝危险性的核心因素，高程和坡度通过控制径流汇聚与排泄效率，成为内涝危险性的基础因子，降雨强度作为气候胁迫因子，直接决定风险等级上限。东部老城区因低洼地形、高不透水率及人口密集成为高风险区。研究结果为山地城市内涝风险精细化管理提供了科学依据，也为多源因子风险评估方法的应用提供了实践参考。

Abstract:

Taking Shapingba District of Chongqing as the research area, aiming at the spatial heterogeneity and dynamic evolution characteristics of urban waterlogging risk in mountainous cities, a comprehensive evaluation system incorporating hazard, exposure and vulnerability is built. A combined subjective-objective weighting method integrating the Analytic Hierarchy Process (AHP) and entropy weight method is used to quantitatively analyze the weights of eight indicators, including rainfall intensity, elevation, slope, population density, road network density and the others. The results show that rainfall intensity (comprehensive weight 0.32), elevation (0.12) and slope (0.24) are the core factors influencing the waterlogging hazard. Elevation and slope serve as the fundamental factors of waterlogging hazard by controlling the runoff convergence and discharging efficiency. As a climatic stress factor, the rainfall intensity directly determines the upper limit of risk levels. The eastern old urban area has become the high-risk area because of its low-lying terrain, high imperviousness and dense population. The research results provide a scientific basis for the refined management of urban waterlogging risks in mountainous cities and offer the practical references for the application of multi-factor risk assessment methods.