Park Samuel, Kim Jaekyoung, Yun Hyeryeong, Kang Junsuk
Research Center for Regional Climate Crisis Response, Seoul National University, Seoul, 08826, South Korea; Lyles School of Civil Engineering, Purdue University, West Lafayette, IN, 47907, USA.
Department of Environmental Landscape Architecture, Gangneung-Wonju National University, Gangneung, 25457, South Korea; (formerly) Research Institute of Agriculture and Life Science, Seoul National University, Seoul, 08826, South Korea.
J Environ Manage. 2024 Nov;370:122344. doi: 10.1016/j.jenvman.2024.122344. Epub 2024 Sep 8.
Urban pluvial floods pose a significant risk to cities, occurring when precipitation exceeds the carrying capacity of the urban drainage network. Coupled green-grey infrastructure has emerged as a sustainable solution for mitigating urban pluvial floods. This study aims to explore best practices in the network configuration of urban drainage systems coupled with low-impact development (LID) to enhance flow distribution and stormwater infiltration. To do so, we focused on two competing key concepts in network analysis: (1) Centralization and (2) Decentralization. We integrated a one-dimensional stormwater model with a rapid flood spreading model to assess the flood mitigation performance of various centralized and decentralized network configurations in the Gangnam region of Seoul, South Korea. To further assess the combined effects of green and grey infrastructure, we compared the performance of each drainage network configuration with and without identical mixed LID practices. Here we show that the centralized drainage network scenario performed best in reducing flood volume by 40.3%, the decentralized drainage network scenario performed best in shortening flood duration by 47.8%, and the LID practices scenario performed best in mitigating peak flooding rates by 4.2%, each as independent scenarios. When all three scenarios were coupled together, flood volume could be reduced by 73.5%, flood duration by 54.7%, and peak flooding rates by 19.8% in the study area. This exploratory study underscores the potential of network analysis in urban flood research, particularly the effectiveness of loosely-connected network topology. Our findings contribute to the development of best practices for coupled green-grey infrastructure, facilitating sustainable stormwater management and urban flood resilience.
城市雨洪对城市构成重大风险，当降水量超过城市排水管网的承载能力时就会发生。耦合的绿色 - 灰色基础设施已成为减轻城市雨洪的可持续解决方案。本研究旨在探索城市排水系统与低影响开发（LID）相结合的网络配置中的最佳实践，以增强水流分布和雨水渗透。为此，我们聚焦于网络分析中的两个相互竞争的关键概念：（1）集中化和（2）分散化。我们将一维雨水模型与快速洪水扩散模型相结合，以评估韩国首尔江南地区各种集中式和分散式网络配置的防洪性能。为了进一步评估绿色和灰色基础设施的综合效果，我们比较了每种排水网络配置在有无相同混合LID措施情况下的性能。我们在此表明，作为独立方案时，集中式排水网络方案在减少洪水量方面表现最佳，减少了40.3%；分散式排水网络方案在缩短洪水持续时间方面表现最佳，缩短了47.8%；LID措施方案在减轻洪峰流量方面表现最佳，减轻了4.2%。当将所有三种方案结合在一起时，研究区域内的洪水量可减少73.5%，洪水持续时间可减少54.7%，洪峰流量可减少19.8%。这项探索性研究强调了网络分析在城市洪水研究中的潜力，特别是松散连接网络拓扑的有效性。我们的研究结果有助于制定耦合绿色 - 灰色基础设施的最佳实践，促进可持续雨水管理和城市防洪能力。
