To effectively utilize the vegetation on grain-for-green slopes in the wind-water erosion
crisscross region，it is necessary to determine the reasonable vegetation utilization intensity． We set
up runoff plots on slopes which were not cultivated and were closed for many years in the Liudaogou
catchment，a typical catchment in wind-water erosion crisscross region of the Loess Plateau． With
artificial simulated rainfall experiments，the characteristics of runoff and sediment yield on slopes
(10°，20° and 30°) under different utilization intensity of vegetation were studied to select the rea-
sonable utilization intensity． The results showed that the runoff rate in the process of rainfall simula-
tion could be divided into two periods: rapidly increasing in the initial period and slow increasing or
quasi-steady state in the middle and late periods． The variation of erosion rate during the rainfall was
dependent on the slope． The utilization intensity had a significant effect on the runoff yield，which
increased with the increasing utilization intensities． The slope gradient had a significant effect on the
sediment yield，with the variation of sediment yield with slope gradient being: 20°＞30°＞10°． Com-
pared with the unused (natural) plots，the relative runoff and sediment increased with increasingutilization intensities． Predicted based on the rainfall data，annual soil erosion amount on the slope
would be basically lower than the tolerance level of soil loss when the vegetation cover on the slope
surface reached 25% in 15 years after abandoning reclamation． More attention should be paid to the
restoration and management of vegetation on the slope of 20° in this area．
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