Abstract:Soil moisture and vegetation growth,as well as the balance of accumulated soil moisture over eleven years,were analyzed for runoff regulation and control projects on level terrace with slope and the terrace as contrast in Anding District,Dingxi City.Results indicated that the level terrace with slope was preserved perfectly,where annual average runoff and sediment yields in runoff generating area(25 m2)were 0.3 m3 and 3.96 kg,respectively.Runoff and sediment were totally retained by impounding area,which effectively controlled soil and water loss,increased water resources,and relieved the water shortage for tree and grass water demands.Soil water content in the 2 m layer varied inversely with vegetation growth.In the terrace as contrast,soil water content was highest,but the reduction of crop yield by drought reached the maximum.In the level terrace with slope,soil water content was lower and alfalfa yield was reduced greater in runoff generating area.In impounding area,however,soil water content was the lowest,while the growth of platycladus orientalis was strong.Annual average evapotranspiration for the level terrace with slope(forests and grass mixed by belts) was 428.6 and 2.2 mm higher than that for the terrace as contrast.