Modeling Effects of Land Use and Slope Gradient on Soil Erosion in a Red Soil Hilly Watershed of Southern China
A study was undertaken to develop appropriate plan of land use under suitable slope gradient to control soil erosion from a small watershed in the red soil hilly region in southern China by using the GeoWEPP model.The model was calibrated and validated using monitoring data of the outlet from 2010 to 2013, in which the annual runoff and sediment yield data were used for calibration, and the 2011 monthly data for validation.The performance of the model in validation period were good with coefficient of determination values of 0.98 and 0.93, Nash-Sutcliffe simulations of 0.96 and 0.91, and deviation values of 17.03 and 16.79, respectively for runoff and sediment yield.Subsequently, the model was used to simulate four typical land use (forest, agricultural, orchard, and fallow land) of the study area to evaluate their impacts on runoff and sediment production.The results showed that the runoff decreased by 44.7% and 61.06% for forest and orchard land as well as the sediment yield decreased by 43.67% and 68.64% compared to the current land use, while the runoff and sediment yield increased by 52.02% and 42.6% for agricultural land, and 48.8% and 29.6% for fallow land.As the same time, the soil erosion increased with increasing of slope gradient of quadratic regression equation for all land use.The critical slope gradient of 15° for returning the farmland to forest or others is suitable in the red soil region, but not accurate.The results of the study can provide scientific evidence for developing appropriate plan of land use in the watershed and other similar areas.
runoff and sediment yield land use slope gradient GeoWEPP red soil hilly region
Zhanyu Zhang Liting Sheng
Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment in Southern China, Ministry of Education, Hohai University, Nanjing 210098, China
国内会议
南京
英文
58-73
2015-07-25（万方平台首次上网日期，不代表论文的发表时间）