Study on Water and Sediment Change and Soil and Water Conservation Effect in Ningxia Section of the Upper Reaches of the Yellow River

Analyzing the impact of soil and water conservation on water and sediment changes is an important prerequisite for scientific understanding the causes of water and sediment change in the Yellow River Basin.Using the methods of water and sediment trend test and sediment balance, this study systematically sorted out the evolution characteristics of water and sand in the Ningxia section of the Yellow River from 1951~2020, explored the cooperative response relationship between water and sand changes in the river basin and regional soil erosion control.The annual runoff along the main stream, Qingtongxia and Shizuishan hydrological stations decreased to varying degrees, with an average annual decrease of 100 million m³.The annual sand loss showed a significant decrease, an annual decrease of 2.5 million tons.The runoff output along the main river-Shizuishan decreased, the degree of "water consumption" in the interval.The sand transport showed a statistical significance, the interval "sediment" output gradually appears.The upstream sediment input is the main source of sediment in the Ningxia Yellow River, accounting for about 56.8%.The interval accounted for 24.8% and 16.3% and only 2.1%. From the 1960s to 1970s, the reservoir sand barrier played a main role in reducing the sediment.After 2000, the area of water and soil conservation measures played an important role in reducing the sand transfer.The relationship between sediment transfer and water and water conservation measures, and the reduction of water and water conservation measures stabilized after 2010.