Evaluating the response and adaptation of urban stormwater systems to changed rainfall with the CMIP6 projections

Yutong Yao; Jiake Li; Yishuo Jiang; Guoru Huang

doi:10.1016/j.jenvman.2023.119135

Evaluating the response and adaptation of urban stormwater systems to changed rainfall with the CMIP6 projections

J Environ Manage. 2023 Dec 1:347:119135. doi: 10.1016/j.jenvman.2023.119135. Epub 2023 Oct 3.

Authors

Yutong Yao¹, Jiake Li², Yishuo Jiang¹, Guoru Huang³

Affiliations

¹ State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, China; Department of Municipal and Environmental Engineering, Xi'an University of Technology, Xi'an, 710048, China.
² State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, China; Department of Municipal and Environmental Engineering, Xi'an University of Technology, Xi'an, 710048, China. Electronic address: xaut_ljk@163.com.
³ School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, 510640, China.

PMID: 37797511
DOI: 10.1016/j.jenvman.2023.119135

Abstract

Climate change is altering urban rainfall characteristics, leading to extreme urban stormwater and, particularly, more frequent flooding. Due to the uncertainty of climate change, the responses of urban drainage systems to climate change are becoming more complicated. This complexity makes it difficult for decision makers to assess whether urban infrastructure is sufficiently resilient to cope with flood risks. In this study, the Xiao Zhai area, a high-density urban area of China, was used as an example. A quantitative method for assessing these risks and the resilience of urban drainage systems to future urban stormwater was developed. First, based on the Coupled Model Intercomparison Project Phase 6 (CMIP6), the variation and uncertainty of future rainfall in the study area were analysed. A high-fidelity hydro-hydraulic model was developed to analyse the influence of climate change on future urban stormwater. Finally, the relationship between urban flood risk and the resilience of urban drainage systems was evaluated. The results show that the temporal distribution of future rainfall from 2023 to 2100 is relatively uniform. However, the number of heavy rainfall events increases significantly during this period. The flood risk caused by future rainfall was one level higher than the historical flood risk. For example, the flood risk caused by future 5a rainfall is equal to the flood risk from historical 10a rainfall. The correlations between the spatial distributions of flood risk and resilience are 0.49-0.63. Urban drainage systems urgently need to be improved and refined in areas with flood risk and low resilience to become more resilient to climate change. Rational planning of grey-green rainwater facilities in flood risk and low resilience areas can improve the rainwater system's resilience to 0.67-0.95 for climate change.

Keywords: CMIP6; Climate change; Design rainfall processes; Flood risk; MIKE FLOOD; Resilience.

MeSH terms

China
Cities
Climate Change*
Floods*
Forecasting
Uncertainty