Impacts of soil-water conservation in Jialing River on sedimentation of the Three Gorges Reservoir

Abstract

The Jialing River is one of the main tributaries of the Yangtze River. The average annual runoff accounts for 16% and the sediment load 26% of the total at Yichang therefore it's one of the main contributors of sediment to the Three Gorges Reservoir. Ever since 1989, our country has implemented “Yangtze River soil and water conservation” project, Till the end of 1996, altogether 25.8% of erosion area in Jialing River has been improved after large scale conservation has taken effect. The analysis and comparison between records taken before and after the implementation of soil and water conservation on runoff and sediment yield indicated that the sediment load soil erosion in Jialing river basin has been taken under control to some extent. Amount of annual runoff in main conservations have generally dropped by exponential function. Obvious result has been achieved in Jialing River, efficiency of sand reduction is about 10%–25%. Therefore, sediment to Three Gorges Reservoir is decreased accordingly, and it will be beneficial to take advantage of reservoir's synthetic benefit.