Hydrological effects of vegetation change in loess slope and small watershed

Based on the measured data of Xiangyanggou small watershed of the Loess Plateau from 1996 to 2001,the impacts of vegetation change on storm runoff,sediment yield and soil moisture are analyzed by scales of runoff plots and small watershed.The results show that,with the increase of vegetation coverage on both runoff plots and small watershed,the contents of soil water,storm runoff and sediment yield are all reduced,and the peak flow is decreased dramatically.The benefit of sediment reduction is greater than that of runoff reduction with increase of vegetation.At the same time,the multi correlation between runoff yield and vegetation coverage as well as other factors is established for grazing plot,and the linear relationship between the content of soil water and vegetation coverage is also established for grazing and arbor plots.