Runoff and Sediment Characteristics of Different Land Use in Hemingguan Watershed
鹤鸣观小流域不同土地利用方式的产流产沙特征

Soil and water loss is very serious in Sichuan Province,and it severely affects local agricultural field.The purple soil is a dominant soil in hilly area of Sichuan.The paper took Hemingguan watershed of Nanbu County in Sichuan province as the case and analyzed the characteristics of runoff and sediment in different land use(that is: barren land,shrubbery,sloping cultivated land,terrace land,woodland and so on),including its relationship with rainfall and effect of reducing water and soil loss.The results show that the difference of runoff and erosion in different land use is significant,runoff coefficient of barren land is maximal and that of woodland is minimal,the erosion modulus of slope cultivation land is maximal and that of woodland is minimal.The runoff coefficient and the erosion modulus are related to the rainfall.The water-and-soil conservation measures have made good effect on reducing water and soil loss,among which the forestry and grass measures have the best effect,followed by the measure of changing slope to terrace,which can increase agricultural yield and therefore has economic benefits.So it is suggested that we should combine the two measures in the purple soil region of Sichuan: in the steep slope we should return land from farming to forestry and in the gentle slope we should take the measure of changing slope to terrace.The study offers an evaluation for the research of characteristics of regional soil and water loss,and for the selection of regional soil and water conservation measures,and establishes a base for the construction of distributed runoff and erosion model.