Determination and projection of flood risk based on multi-criteria decision analysis (MCDA) combining with CA-Markov model in Zhejiang Province, China

• Published in: Urban climate Vol. 53; p. 101769
• Main Authors: Wu, Xu, Shen, Xiaojing, Li, Jianshe, Xie, Xinmin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2024
• Subjects: AHP method; CA-Markov; Flood risk; Fuzzy method; Zhejiang; AHP method; CA-Markov; Fuzzy method; Zhejiang; Flood risk
• ISSN: 2212-0955; 2212-0955
• DOI: 10.1016/j.uclim.2023.101769

The determination and projection of flood risk level is an important problem for disaster management decision-makers, especially for densely populated and economically developed Zhejiang Province, China. This study generated a flood risk map for 2020 adopting 11 parameters and projected flood risk maps for 2025 and 2030 by adopting the CA-Markov method spatially. The data were first homogenized using the fuzzy method. Next, the analytic hierarchy process (AHP) method calculates the weight of each parameter and generates a flood risk distribution map. Statistical analysis of flood disasters in the study area and the support of other research results showed that the proposed model performed well in mapping flood risk. The map showed that 15.19% of the study area was in the high-and extremely high-risk classes, and was mainly concentrated in the southeast coastal area and Hangzhou Bay area. The Receiver Operator Characteristic (ROC) curves (AUC2015 = 0.887, AUC2020 = 0.891) verified the excellent performance of the CA-Markov method in projecting flood risk. Finally, the CA-Markov method was adopted to project the risk distribution map of future flood areas, and the results showed that the high-risk areas for flooding in the southeast coastal area and northern Hangzhou Bay area will be further expanded in 2025 and 2030. •Analyze the parameter using the fuzzy method combined with the analytic hierarchy process.•A flood risk map for the study in 2020 is generated adopting 11 parameters.•Forecasting the flood risk maps in 2025 and 2030 with the CA-Markov method.•The high-risk flood risk region of the study area will be expanded in 2025 and 2030.