The Spatial Exposure of China’s Infrastructure System to Flooding Risks in the Context of Climate Change
Extreme weather events in China, expected to become increasingly common because of climate change, pose a grave threat to essential infrastructure that provides running water, electricity, road and railway connections. This research looks at the fundamental issues of understanding the vulnerability and risks to Chinese infrastructures due to adverse climate impacts. The authors have developed a suite of infrastructure (energy, transport, water, waste and ICT) models to understand how exposed China's infrastructure is to various potential climate change impacts. A concept called the “infrastructure criticality hotspot” is used which is defined as a geographical location where there is a concentration of critical infrastructure, measured according to the number of customers directly or indirectly dependent upon it. Key findings from this research show that China’s top infrastructure vulnerability hotspots are Beijing, Tianjin, Jiangsu, Shanghai and Zhejiang. Using spatial hydrological models, the authors then investigate how these areas may be affected by flooding. The research shows that railways, aviation, shipping, electricity, and waste water in Anhui, Beijing, Guangdong, Hebei, Henan, Jiangsu, Liaoning, Shandong, Shanghai, Tianjin, Zhejiang —and their 66 cities —are exceptionally exposed. The average number of people who use these services and could be disrupted by the impacts of flooding stands at 103 million.
To deepen the understanding of how climate change will affect the Chinese infrastructure system, the authors look at how future flooding probabilities will change according to different emission scenarios. To this end, the results of a global river routing model – the Catchment-Based Macro-scale Floodplain (CaMa-Flood) – are used to project future flood hazard given scenarios RCP 4.5 and RC 8.5. It is observed that most models show that infrastructure hotspots are in areas of increasing flooding probabilities. Jiangsu, Anhui, Hubei, northern Hunan and Jiangxi, western Heilongjiang, eastern Inner Mongolia, Liaoning provinces all may incur increasing flood hazard for their infrastructures. To demonstrate infrastructure exposure to changing flood risks more specifically, the authors show a case study of the electricity sector and its exposure to changing flood probabilities given RCP 4.5 and RCP 8.5 for a set of optimistic, medium and pessimistic scenarios.