Zhu Yue, Burlando Paolo, Tan Puay Yok, Blagojevic Jovan, Fatichi Simone
Institute of Environmental Engineering, ETH Zurich, Switzerland.
Institute of Environmental Engineering, ETH Zurich, Switzerland.
Sci Total Environ. 2024 Nov 25;953:176139. doi: 10.1016/j.scitotenv.2024.176139. Epub 2024 Sep 7.
As climate change intensifies, cities globally are experiencing more severe rainfall and frequent pluvial floods. Urban expansion is altering the permeability of the land, thus increasing the risk of flooding. This study investigates the impact of urban morphology on pluvial floodwater distribution in 15 urban catchments across England, UK, to provide an analysis of how urban morphology influences flood magnitude. Using a cellular automata-based model, pluvial flood simulations were conducted for catchments characterized by diverse urban morphologies. Then a series of machine learning models were adopted to reveal the relationships between the morphological characteristics of urban configurations (e.g., building footprints, impervious surfaces, street network, topography) and pluvial flooding. These models were used to identify and quantify the effects of key urban morphological indicators on pluvial flooding. The results indicate that, although the total area of impervious surfaces plays the most significant role in floodwater distribution, the edge density (ED) of building footprints and impervious surfaces also influences this process. Synthetic experiments with an exemplary urban fabric show that decreasing "ED of building footprint" and increasing "ED of impervious surface" can mitigate flood volume by up to 6.3 % at 100 % drainage efficiency and 7.8 % at 50 % efficiency. The results of this study are anticipated to aid urban planners and policymakers in developing strategies for implementing flood-resilient cities.
随着气候变化加剧，全球城市正经历更严重的降雨和频繁的雨洪灾害。城市扩张正在改变土地的渗透性，从而增加了洪水风险。本研究调查了英国英格兰15个城市集水区的城市形态对雨洪分布的影响，以分析城市形态如何影响洪水规模。使用基于元胞自动机的模型，对具有不同城市形态的集水区进行了雨洪模拟。然后采用一系列机器学习模型来揭示城市形态特征（如建筑占地面积、不透水表面、街道网络、地形）与雨洪之间的关系。这些模型用于识别和量化关键城市形态指标对雨洪的影响。结果表明，尽管不透水表面的总面积在洪水分布中起最重要作用，但建筑占地面积和不透水表面的边缘密度（ED）也会影响这一过程。对一个典型城市结构的综合实验表明，在排水效率为100%时，减少“建筑占地面积的ED”和增加“不透水表面的ED”可使洪水量减少多达6.3%，在效率为50%时可减少7.8%。预计本研究结果将有助于城市规划者和政策制定者制定建设抗洪城市的策略。
