Evaluation of Flood Resilience and Analysis of Obstacle Factors in Xiangjiang River Basin Based on PSR-TOPSIS Models and River System Evolution

Flood disasters are one of the most significant natural hazards threatening the sustainable development of cities, and enhancing urban flood resilience is crucial for achieving sustainable development. From a resilience perspective, this study constructed a comprehensive flood resilience evaluation indicator system based on the pressure-state-response (PSR) framework by taking into account the complex relationship between water system indicators and flood resilience across different value ranges. The system was developed from multiple dimensions, including natural, social, and economic factors. By taking the Xiangjiang River Basin as the study area, the technique for order preference by similarity to ideal solution (TOPSIS) combined with the entropy weight method was employed to quantify flood resilience levels, while the obstacle degree model was used to identify key constraints affecting flood resilience. The results indicate that: ① The overall flood resilience of the basin shows a fluctuating upward trend, with an increase of 77.22% during the study period. ② The growth rates of resilience vary significantly among cities within the basin. As the capital city of Hunan Province, Changsha has experienced rapid economic development, resulting in the highest increase in flood resilience, transitioning from a lower to a higher resilience level. In contrast, Loudi City has shown the lowest progress in flood resilience among all the cities. ③ The primary obstacles hindering the improvement of flood resilience are predominantly concentrated in the response and state subsystems, including total wages of on-the-job employees, reservoir capacity, and length of flood control embankments. In the future, enhancing flood resilience should focus on indicators of the state and response subsystems, such as the total wages of on-the-job employees, reservoir capacity, and the length of flood control embankments. This study can provide valuable references for river system protection, flood risk management, and urban resilience construction in the Xiangjiang River Basin and other similar regions.