Benefits of Sediment Reduction of Soil and Water Conservation Measures in Chenggou Dam System Watershed

On the basis of observed data of 5years of precipitation,runoff,slit and soil and water conservation measures as well as research in Chenggou Dam system watershed,QuickBird remote sensing images as the major information source,ArcGIS 9.3 and RegionManager 5.5,precipitation variation and soil and water conservation measures on runoff and sediment yield in the watershed were studied,the benefits of water and sediment interception under the conditions of different soil and water conservation measures were analyzed.Some results were gained as followings:from 2007 to 2011,soil and water conservation construction measures is the main reason of runoff and sediment reduction,the area of countermeasures increased 133.04hm2,the control dam system watershed area reached to 8 843.58hm2,accounting for 54.80% of the total basin.Annual average erosion modulus is 18.80t/km2 in Chenggou Dam system watershed,erosion modulus reduced by 5 581.20t/km2.