PROGRESS IN GEOGRAPHY ›› 2021, Vol. 40 ›› Issue (8): 1355-1370.doi: 10.18306/dlkxjz.2021.08.009

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Risk assessment of extreme flood in the north bank of the Hangzhou Bay under land use change scenarios

JIANG Li(), YU Jia*(), WEN Jiahong, TANG Jin, QI Manfei, WANG Luyang, ZHANG Min   

  1. School of Environmental and Geographical Sciences, Shanghai Normal University, Shanghai 200234, China
  • Received:2020-11-03 Revised:2021-04-18 Online:2021-08-28 Published:2021-10-28
  • Contact: YU Jia;
  • Supported by:
    National Natural Science Foundation of China(72074151);National Natural Science Foundation of China(51761135024);Natural Science Foundation of Shanghai(20ZR1441500);National Key Research and Development Program of China(2017YFC1503001)


The Hangzhou Bay, located in the Yangtze River Delta, is characterized by broad distribution of tidal flats and wetlands. As sea levels continue to rise in the future, natural hazards, especially storm surges, will be more likely to occur, which will have a great impact on the socioeconomic development of the region. Based on multi-year land use and assets data, this study conducted a simulation of the spatiotemporal change of elements at risk and exposures in the north bank of the Hangzhou Bay. The simulation is based on predictions of future variations in land use and assets and multiple extreme flooding scenarios, in order to assess the losses of flood disasters in the region. The results show that: 1) High values of asset losses per unit area under the current scenario appear in the south of Pudong New District. In future scenarios, high values of asset losses per unit area will cover the entire southern coastal area and the northern Jinshan District in the north bank of the Hangzhou Bay. 2) The entire study area will witness a growth in asset exposure and losses under extreme flooding scenarios as the GDP and the exposed and inundated area increase. The expected annual damage will rise from 65 million yuan under the current scenario to 304 million yuan under the representative concentration pathway (RCP) 8.5H scenario in the future. The risk assessment results indicate that the north bank of the Hangzhou Bay is susceptible to extraordinarily large floods. Thus, risk-sensitive urban planning must be implemented. The standards and specifications on residential communities and infrastructures in the region must be updated. Meanwhile, comprehensive preventive measures must be taken to enhance the flood control capabilities along the banks of the Hangzhou Bay. This study can provide a basis for decision making of risk-based urban planning, flood-risk adaption measures, and resilience improvements within the study area. The proposed research method is more reasonable and effective than the traditional methods of assessing future economic losses, which are often based only on current land use and asset values. It can also provide a methodological reference for risk assessments of other coastal regions.

Key words: land use simulation, risk assessment, future scenario, SLEUTH model, north bank of the Hangzhou Bay