Measurement and analysis of water ecological carrying capacity in the Yangtze River Economic Belt, China

Water ecological carrying capacity (WECC) is a crucial index for measuring regional sustainable development. To investigate the evolution of WECC in the Yangtze River Economic Belt (YREB), this study constructed a comprehensive index system consisting of 23 indicators from six interconnected dimensions of water systems. The back propagation neural network (BPNN) model was used to quantify WECC in YREB from 2010 to 2021, and ArcGIS was utilized to visualize the distribution of WECC. To identify sensitive indicators under subsystems, sensitivity analysis was conducted based on the one-at-a-time (OAT) method. Additionally, time-series prediction of WECC was performed using the exponential smoothing (ES) method. Finally, the coupling coordinated degree (CCD) of subsystems in each province from 2010 to 2021 was calculated. The results indicated that the average WECC in YREB gradually increased from 2010 to 2021, with significant provincial differences. Sensitivity analysis revealed that R-1, U-2, Q(4), S-2, M-3 and B-1 had the most substantial impacts on the WECC of subsystems (Sub-CC). The fitting curve between the CCD and WECC showed that as CCD increased, the growth rate of WECC gradually slowed down. Based on these findings, relevant suggestions were proposed to improve WECC and promote the regional sustainable development in YREB.