A new framework for assessing coordinated water management in arid river basins: A case study of the Tarim River Basin

Identifying appropriate coupling and coordination dimensions for arid river basins remains challenging, yet it is essential for understanding the dynamic evolution of water resources systems and developing multi-dimensional collaborative management strategies. This study integrates 77 detailed indicators to construct a “water quantity-water quality-water area-water flow-water and ecology” (WQAFE) coupling coordination degree (CCD) and multi-objective optimization management model based on all-element analysis, enabling the identification of key processes and driving factors. The results show that, during 2000–2022, the development level of the four Source Rivers of the Tarim River Basin (TRB) in the WQAFE dimensions was generally higher than that of the mainstream of the TRB, with significant improvements in the water quality and water area subsystems, but relatively small improvements in the water and ecology subsystem. Meanwhile, the evolution of all subsystems was increasingly influenced by human activities. The overall WQAFE-CCD of the TRB increased from 0.467 to 0.636, shifting from Near disarray decline (0.40 < D ≤ 0.50) to Primary coordinated development (0.60 < D ≤ 0.70). The CCD level of the four Source Rivers was higher than that of the mainstream of TRB, although the latter exhibited more significant improvement. The most sensitive factor for the development of CCD shifted from total water resources (natural water availability) to total water use (anthropogenic water demand). Multi-scenario simulations showed that the medium-intensity supply-demand balance regulation scheme under the combined scenario of vegetation restoration and water resources management could overcome the limitations of single-dimensional optimization by avoiding system imbalance and alleviating the decline in water area stability caused by increased water volume. This scheme increased the probability of achieving a high CCD state by 31.2% and simultaneously improved multiple water system indicators. These findings highlight the importance of multi-dimensional coordinated management for maintaining water resources system stability in arid river basins, such as the TRB.