Urban Flood Risk Assessment Based on DEMATEL-ANP Hybrid Fuzzy Evaluation and Hydrodynamic Model

The escalating severity of urban flood issues endangers both civilian security and property safety. Urban flood risk assessment delivers critical guidance for urban flood risk management and flood-prevention planning. This study introduces a hybrid methodological model for assessing urban flood risks that integrate scenario simulation and index system methodologies. A hydraulic model was established to simulate water accumulation scenarios in urban areas, thereby acquiring requisite data for the index system. The causal dependencies among indexes were identified through the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method, while indexes weights were obtained by hybridized Analytic Network Process (ANP) method. Finally, a fuzzy comprehensive evaluation (FCE) method is applied to complete the risk assessment. The results showed that the area proportions corresponding to the five risk levels (low risk, relatively low risk, moderate risk, relatively high risk, and high risk) in the study area are 68.98%, 22.75%, 0.86%, 0.10%, and 7.31%, respectively. By using the raster calculation method, the model evaluation can achieve a 10 m × 10 m spatial resolution, which is suitable for fine simulation at small scales within the city, and provides specific high-risk locations for flood-prevention planning.