Assessing the Influences of Land Use Change and Climate Change on Runoff in Kaidu River Basin Based on Swat Model

Assessing the influences of land use change (LUC) and climate change (CC) on hydrological processes is of great significance in water resources management. The primary aim of this study is to conduct a quantitative evaluation of the contribution of both LUC and CC on the runoff change within the Kaidu River Basin, Xinjiang. In detail, the Soil and Water Assessment Tool (SWAT) is constructed based on GIS technology to carry out month-by-month runoff simulation. Then, the simulated runoff of the Kaidu River Basin from 1957 to 2007 is calibrated and validated using the SWAT-CUP software. The contributions of both CC and LUC to runoff can be achieved through the utilization of empirical equations. Results show that: (i) in the calibration period, the SWAT model exhibits a coefficient of determination (R2) value of 0.76 and a Nash–Sutcliffe efficiency (NSE) value of 0.70, whereas in the validation phase, the corresponding values are 0.63 and 0.61, respectively. (ii) the contribution rates of CC and LUC to runoff variation are 55.8% and 44.2%, respectively. Therefore, CC is the main driving force causing an increase in the runoff in the Kaidu River. Findings are helpful for providing strategies for future prediction and management of water resources in the Kaidu River Basin.