Runoff Simulation of Land-use Changes Based on the Different Slopes of Erhai Basin Using SWAT Model

Changes of land use/land cover have a significant impact on runoff by altering the 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 runoff of land-use changes of different slopes using GIS technology and SWAT model in Erhai watershed. The results show that land cover changes make a big difference on ecological environment. The runoff has increased to some extent by changing the pasture and agriculture which slope above 15o to forests. Changing forest to agriculture, pasture have little effect on runoff between the slope of 15o and 20o, but turning forest to agriculture and pasture reduce runoff 30.77 mm, 14 mm respectively. Pasture to agriculture which the slope above 15o increases runoff considerably, scenario 4 and scenario 9 increase runoff 49.11 mm, 48.99mm respectively.