Institute of Remote Sensing and Earth Sciences, Hangzhou Normal University, Hangzhou, 311121, China.
Institute of Remote Sensing and Earth Sciences, Hangzhou Normal University, Hangzhou, 311121, China; Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, Hangzhou, 311121, China.
J Environ Manage. 2024 Feb 27;353:120113. doi: 10.1016/j.jenvman.2024.120113. Epub 2024 Jan 28.
The growing incidence of urban flood disasters poses a major challenge to urban sustainability in China. Previous studies have reported that climate change and urbanization exacerbate urban flood risk in some major cities of China. However, few assessments have quantified the contributions of these two factors to urban flood changes in recent decades at the nationwide scale. Here, surface runoff caused by precipitation extremes was used as the urban flood hazard to evaluate the impacts of climate change and urbanization in China's 293 major cities. This study assessed the contributions of these drivers to urban flood hazard changes and identified the hotspot cities with increased trends under both factors during the past four decades (1980-2019). The results showed that approximately 70% of the cities analyzed have seen an increase of urban flood hazard in the latest decade. Urbanization made a positive contribution to increased urban flood hazards in more than 90% of the cities. The contribution direction of climate change showed significant variations across China. Overall, the absolute contribution rate of climate change far outweighed that of urbanization. In half of the cities (mainly distributed in eastern China), both climate change and urbanization led to increased urban flood hazard over the past decade. Among them, 33 cities have suffered a consecutive increase in urban flood hazard driven by both factors.
城市洪涝灾害的发生率不断上升，对中国城市的可持续发展构成了重大挑战。先前的研究报告称，气候变化和城市化加剧了中国一些大城市的城市洪涝风险。然而，很少有评估在全国范围内量化这两个因素对近几十年来城市洪涝变化的贡献。在这里，利用极端降水引发的地表径流作为城市洪涝灾害来评估气候变化和城市化对中国 293 个主要城市的影响。本研究评估了这些驱动因素对城市洪涝灾害变化的贡献，并确定了在过去四十年（1980-2019 年）期间，在这两个因素下，城市洪涝灾害呈上升趋势的热点城市。结果表明，在所分析的城市中，约有 70%的城市在最近十年中城市洪涝灾害风险有所增加。城市化对 90%以上城市的城市洪涝灾害增加做出了积极贡献。气候变化的贡献方向在中国各地存在显著差异。总体而言，气候变化的绝对贡献率远远超过城市化。在一半的城市（主要分布在中国东部）中，过去十年中，气候变化和城市化都导致城市洪涝灾害风险增加。其中，有 33 个城市因这两个因素的共同作用而导致城市洪涝灾害风险连续增加。
