Research on Water Ecological Resilience Measurement and Influencing Factors: A Case Study of the Yangtze River Economic Belt, China

Industrial development and population expansion has had serious negative impacts on the water ecological environment, and enhancing water ecological resilience (WER) has become a new sustainable development goal. Current research on WER is mostly about ecological resilience assessment including water systems. In order to explore the WER of the Yangtze River Economic Belt (YREB), ecological resilience and water ecology were combined to form the concept of WER. Based on the "social-ecological" resilience perspective, a DCSMI (Driving Force-Carrying Capacity-State-Management-Innovation) WER evaluation index system was constructed, which consists of five subsystems. The WER of the YREB from 2011 to 2022 was measured by using game-theoretic combination weights and the comprehensive evaluation method, which were then combined with the kernel density (KD) estimation, the Thiel index, and the center of gravity-standard deviation ellipse (SDE) method to reveal the WER differences and spatial evolution characteristics of the YREB. Finally, the key factors influencing WER were explored using the BP-DEMATEL model. It was found that (1) the average value of WER in the YREB has declined from 0.4562 to 0.4442, the polarization of WER is obvious, the overall gap is on a widening trend, and the gap between different basins is the main reason for the differences in WER in the YREB. (2) The WER of the YREB presents an asymmetric U-shaped distribution pattern with the downstream optimal, upstream medium, and midstream worst, and the spatial evolution presenting a northwestern-southeastern pattern. (3) The key factors of the top-ranked provinces in the WER index are concentrated in the layer of the State (S) indicators, the middle-ranked provinces and the back-ranked provinces are more influenced by the Driving Force (D) and the Carrying Capacity (C) indicators, respectively, and the Management (M) and Innovation (I) indicators are distributed in several provinces. These results can provide theoretical support for the construction of "resilient cities" and water ecology optimization in the YREB.