文章信息：Long Yang, Yixin Yang, Ye Shen, Jiachuan Yang, Guang Zheng, James Smith & Dev Niyogi. (2024). Urban development pattern’s influence onextreme rainfall occurrences. Nature Communcations: 15, 3997. https://doi.org/10.1038/s41467-024-48533-5.
整理人：杨文，2023级硕士生
整理时间：2024年5月16日
Abstract: Growing urban population and the distinct strategies to accommodate them lead to diverse urban development patterns worldwide. While local evidence suggests the presence of urban signatures in rainfall anomalies, there is limited understanding of how rainfall responds to divergent urban development patterns worldwide. Here we unveil a divergence in the exposure to extreme rainfall for 1790 inland cities globally, attributable to their respective urban development patterns. Cities that experience compact development tend to witness larger increases in extreme rainfall frequency over downtown than their rural surroundings, while the anomalies in extreme rainfall frequency diminish for cities with dispersed development. Convection-permitting simulations further suggest compact urban footprints lead to more pronounced urban-rural thermal contrasts and aerodynamic disturbances. This is directly responsible for the divergent rainfall responses to urban development patterns. Our analyses offer significant insights pertaining to the priorities and potential of city-level efforts to mitigate the emerging climate-related hazards, particularly for countries experiencing rapid urbanization.
摘要：不断增长的城市人口和容纳他们的独特策略导致了多样化的城市紧凑型发展，与农村环境相比，市中心的极端降雨频率增加幅度更大，而分散发展的城市的极端降雨次数异常现象有所减少。允许对流的模拟进一步表明，紧凑的城市足迹会导致更明显的城乡热对比和空气动力学扰动。这是降雨对城市发展模式的不同反应的直接原因。我们的分析提供了与城市一级努力的优先事项和潜力有关的重要见解，以缓解新出现的气候相关危害，特别是对于正在经历快速城市化的国家。
图 不同的城市发展模式和相关的空间降雨模式异常
（a）三种城市扩张方式：类型I：城市覆盖度低、城市化速率低、城市布局离散；类型II：城市覆盖度高、城市化速率低、城市布局紧凑；类型III：城市覆盖度低、城市化速率快、城市布局离散。（b-d）降雨异常空间分布。第二种紧凑型城市扩张在城区及附近地区产生了较大的降雨增加；而另外两种增加不明显，其中第三种离散型的快速城市扩张，降雨增加主要集中在郊区。
图 不同城市扩张方式影响降雨的概念模型
（a）紧凑型，在市中心及下风向产生降雨（b）离散型，在郊区产生降雨。阴影颜色表示城乡热力差异，暖色表示更高的地表温度，冷色反之。箭头表示气流的速度和方向。
原文链接：https://www.nature.com/articles/s41467-024-48533-5#Fig1
节选转引：https://mp.weixin.qq.com/s/WRQHcbGCgSaoZ7ekEFBsOg
