Study on empirical rainfall-sediment model of Xihanshui river

The Xihanshui river is in the south of Qinling Mountains.In the upstream of the river,there is a loess area of 2 350 km\+2,being a major sediment yielding area in Jialing river basin.Since the execution of Soil-water conservation project in middle and upstream area of Yangtze from the end of 1980s,large-scale soil-water harnessing works was carried out in the major sediment yielding area of the Xihanshui river basin,up to 1996,the harnessed area amounted to 40% of the total soil-water loss area.The measures of soil-water conservation had played an important role in controlling the soil-water losses in the Jialing river basin.Taking the Shunlixia hydrometric station in the upstream of the river as a major analysis point and based on the measured data,this paper analyses the empirical models of precipitation-runoff and precipitation-sediment of upper Xihanshui basin under the natural condition and the variation of discharge and sediment after the execution of soil-water conservation measures in the region.