Change law in runoff and soil erosion from a watershed in the central Yunnan Province after conservation implementation

In order to control soil and water loss in the small Wangjiajing watershed in the central Yunnan Province, engineering, biological and crop cultivation measures have been implemented. The data of climate, hydrology and soil erosion have been collected and analyzed. It is concluded that rainfall, runoff and soil erosion in the small Wangjiajing Watershed are concentrated from May to October. And there are significant positive correlations between value of multiplying rainfall and maximum 30-minute rainfall intensity and runoff, and sediment for a single rainfall(R=0.956^**, 0.993^**). The relationship is expressed as unitary cubic equation. The equation for monthly rainfall and runoff and sediment is unitary power function (R=0.819^**, 0.985^**). It is indicated that engineering, biological and crop cultivation measures are effective to reduce soil and water loss in this small watershed.