Distributed hierarchical evaluation and carrying capacity models for water resources based on optimal water cycle theory

Abstract

Water cycles protect and maintain ecological environments, while enabling sustainable development of human societies. Various approaches have been proposed for maintaining optimal water cycles. This study developed an evaluation system based on both natural and social attributes of the water cycle. The system incorporated the four dimensions of water ecology, water quality, water quantity, and water use in a distributed hierarchical evaluation model. A water resources carrying capacity model was also constructed. Both models were evaluated using the Beijing–Tianjin–Hebei region as a case study. Statistical data from 13 prefecture-level cities were used to assess the water cycle status of this region. Overall, the water cycle status of the Beijing–Tianjin–Hebei region received a score of 3.33, indicating normal status (although this value varied throughout the region) and the standard deviation of the values was up to 0.48. Results suggested that although water use efficiency is close to ideal, insufficient water resources prevent the region from achieving an optimal regional water cycle. Feasible approaches to more sustainable water resource development within the Beijing–Tianjin–Hebei region include developing interregional cooperation, promoting population–industry relocation, and supplementing shortages with interbasin water transfers.