Dynamic evaluation and the binary coupling driving mechanism of water resources carrying capacity: A case study of the Beijing-Tianjin-Hebei urban agglomeration

Studying and optimizing water resources carrying capacity(WRCC) is an inevitable requirement for regional water security guarantee and sustainable development. The existing evaluation methods ignore the temporal dynamics of WRCC, and the research on the driving mechanism of WRCC is not yet comprehensive, which limits the reference value of the research results.This study constructed a new time-weighted-varying VIKOR method to assess WRCC dynamically, and based on obstacle diagnosis model and optimal parameter-based geographical detector, revealed the obstacle factor and driving factor of WRCC. A case study was carried out in the Beijing-Tianjin-Hebei urban agglomeration(BTH) to verify the rationality and reliability of the method. The results show that: (1) The entropy-CRITIC method can allocate the weight more reasonably and avoid overly average or extreme weight distribution (2) Time-weighted-varying VIKOR accurately capture the dynamic change direction and rate of WRCC in each city of BTH, where Baoding has the fastest improvement rate, and Tianjin has the greatest multi-year change range. (3) The binary coupling effect of “driving-obstacle” were comprehensively deconstruct. The most significant indicator to restrict WRCC and cause spatial differentiation of driving forces of BTH is the ecological water consumption, followed by urbanization rate, per capita GDP, proportion of secondary production. These research 1results can help decision-makers understand the long-term trends of WRCC changes in the BTH, and provide a reference for optimizing regional water resource allocation and water usage structure, improving the ecological environment, adjusting the industrial structure, and optimizing the spatial layout of urban population.