Runoff simulation of land-use changes based on the different slopes of Erhai basin by using SWAT model

Changes of LUCC have a significant impact on runoff by altering surface evaporation, soil moisture conditions, and the amount of trapped ground cover, which directly impact the sustainable development of the watershed ecology. In this paper, based on remote sensing images, we simulate the runoff of land-use changes of differing slopes using GIS technology and SWAT model in Erhai basin. The results show that land cover changes make a big difference on the ecological environment. Runoff is increased to some extent by changing the pasture and agriculture slope above 15° to forests. Changing forests to agriculture, pasture has little effect on runoff between the slope of 15° and 20°, but turning forests to agriculture and pasture reduces runoff ny 30.77 mm and 14 mm respectively. Pasture to agriculture above 15° increases runoff considerably, and runoff is increased by 49.11 mm and 48.99 mm, respectively, in scenario 4 and scenario 9.