HYDROLOGICAL EFFECTS OF VEGETATION CHANGE ON LOESS SLOPES AND IN SMALL WATERSHEDS

摘要

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