Impacts of Climate Change on Urban Extreme Rainfall and Drainage Infrastructure Performance: A Case Study in Wuhan City, China

The design of stormwater drainage infrastructure in urban areas in China is based on the statistical stationary assumption of probability distribution of extreme rainfall, which is being increasingly challenged by climate change. However, quantitative assessment of the performance of urban drainage systems in response to climate change with the latest emission scenarios of the Coupled Model Intercomparison Project Phase 5 in China is quite limited. This study aims to investigate potential changes of extreme rainfall and their influence on drainage infrastructure in a representative urban area in Wuhan city, China. The Storm Water Management Model is established to investigate the response of drainage infrastructure to future design rainfall. It is found that the probability distribution of extreme rainfall for two historical sub‐periods (1961–1985 and 1986–2005) has changed, especially in the head and tail of the frequency curves. Furthermore, the design rainfall with return periods of 2, 3, 4 and 5 years increases more significantly than those of 10 and 20 years. Consequently, the incapability of the current drainage infrastructure in the study area is aggravated. Moreover, the results of SWMM modelling provide detailed information about the performance of current drainage infrastructure, which can provide technical support for future modifications of the current drainage infrastructure of the study area. © 2018 John Wiley & Sons, Ltd. Résumé La conception de l'infrastructure de drainage des eaux pluviales en zone urbaine en Chine est basée sur l'hypothèse statistique stationnaire de la distribution de probabilités de précipitations extrêmes, ce qui est de plus en plus contestée par le changement climatique. Cependant, l'évaluation quantitative de la performance du système de drainage urbain en réponse au changement climatique avec les derniers scénarios d'émission de la phase 5 du projet d'intercomparaison de modèles couplés (CMIP5) en Chine est assez limitée. Cette étude vise à étudier les changements potentiels des précipitations extrêmes et leurs influences sur les infrastructures de drainage dans une zone urbaine représentative de la ville de Wuhan en Chine. Le modèle de gestion des eaux pluviales (SWMM) est établi pour étudier la réponse de l'infrastructure de drainage aux pluies de conception futures. On constate que la distribution de probabilité de précipitations extrêmes pour deux sous‐périodes historiques (1961–1985 et 1986–2005) a changé, en p