Coupling coordination degree, interaction relationship and driving mechanism of water resources carrying capacity of Beijing-Tianjin-Hebei urban agglomeration in China

The sustainable use of water resources is important for the sustainable development of society, economy and ecoenvironment. Water resources carrying capacity (WRCC) reflects regional development levels, influenced by subsystems of water resources, society, economy and eco-environment. Previous studies focused on quantification of WRCC, with limited exploration of coupling coordination or driving mechanisms between subsystems. Therefore, this study focuses on the Beijing-Tianjin-Hebei urban agglomeration with high WRCC pressure. Based on the quantification of WRCC, this study applies coupling coordination degree model to assess the coordination relationship between subsystems. Then, using panel vector auto regression model to explore the interaction relationship between subsystems. Next, using geographically and temporally weighted regression model and geodetector model to identify driving forces from subsystems and evaluation indicators. Finally, we proposed relevant development suggestions. The results show that: (1) The coupling coordination degree in the BeijingTianjin-Hebei urban agglomeration from 2003 to 2020 shows a positive development trend, with fluctuating rises between the water resources and the other three subsystems. (2) The water resources subsystem and society subsystem are central to dynamic interactions The eco-environment is the primary subsystem for WRCC. (3) Per capita GDP, urbanization rate, water consumption per 10 thousand CNY GDP, sewage treatment rate and per capita industrial sulfur dioxide emission are the main driving indicators for WRCC development. This study provides new insights for improving the WRCC and provides a basis for regional high-quality, sustainable and coordinated development. It also rationalizes the allocation of water scheduling between production, living and ecology.