Integrated modeling framework for evaluating and predicting the water resources carrying capacity in a continental river basin of Northwest China

Although water is the material basis of human being survival and development, it exhibits inhomogeneity in time and space, which makes it difficult to accurately evaluate the supply and consumption relationship of water resources and its carrying capacity in arid regions. An innovative integrated modeling framework was proposed to dynamically evaluate and predict the water balance and water resources carrying capacity in a continental river basin of Northwest China by coupling the Soil and Water Assessment Tool (SWAT), water resources supply and consumption model, Principal Component Analysis (PCA) and Fuzzy Comprehensive Evaluation (FCE). The following results were obtained: i) the integrated methodology between the SWAT distributed hydrological model and the water resources evaluation model is an important tool for predicting the regional water resources carrying capacity, which has dynamic, advanced, comprehensive and systematic features; ii) from 2000 to 2007, the available water resources in the Heihe River Basin were almost all in the state of shortage, although the water shortage rate decreased gradually and changed from 35% in 2006 to −0.49% in 2007, with 2001 exhibiting the most serious drought period (maximum water shortage rate of 62.77%); iii) the water resources carrying capacity in the upper reaches of Heihe River Basin from 2010 to 2015 showed an overall increasing trend; iv) the pressure risk on the water resources carrying capacity in the upper reaches of Heihe River Basin from 2015 to 2025 indicates gradual and specific changes, with good results observed in 2015, moderate results observed in 2020, and relatively poor results observed in 2025; and v) collaborative and sustainable water resources management strategies are recommended from four dimensions, water resources amount, water environment capacity, water spaces and water dynamics. The results may provide insights for guiding the optimal scheme design of water resources allocation in a continental river basin with arid regions.