Analysis of Hydrological Elements and Runoff Prediction in Tao'er River Basin under Land Use and Climate Change

［Objective］ To reveal the characteristics of the response of runoff to land use and climate change in the Tao'er River basin, and to predict the future evolution of runoff in the basin. ［Methods］ Taking the Tao'er River basin as the study area, the runoff response process of the watershed was quantitatively analyzed based on the SWAT model with the CMIP6 climate model and PLUS model driving meteorological and land use changes, respectively, to project development scenarios for 2025—2100. ［Results］ 1) The SWAT model had an R2>0.75 and an NSE>0.65 for both the rate period and the validation period. The overall accuracy of the PLUS model was >0.85, and the Kappa coefficient was >0.80, and the two models had good applicability in this watershed.2) Relative to the baseline period (1990—2022), the Tao'er River Basin received higher precipitation under all three future scenarios than during the historical period, as shown by SSP126>SSP585>SSP245, and higher temperatures under all three future scenarios than during the historical period, as shown by SSP585>SSP245>SSP126. 3) During the period of 2025—2100, the areas of cropland, watersheds, and unutilized land in the Tao'er River Basin increased significantly, while the area of forested land increased slowly, and the areas of grasslands and built-up lands continued to decrease. 4) The average annual runoff in the future period would exceed the level of the base period under the SSP126 scenario, while it would be lower than the level of the base period under the SSP245 and SSP585 scenarios, and the average multi-year runoff under the three scenarios would be 11.17×108, 9.00×108 and 9.34×108 m3/s. ［Conclusion］ The Tao'er River basin's future runoff change presents the trend of continuous growth, therefore should enhance the flood control consciousness when the annual average runoff reaches the maximum value in three level years, the results can provide certain reference basis for reasonable development and construction of the Tao'er River basin in the future.