Estimate of sedimentation volume in the Longyangxia Reservoirx

摘要

Tangnaihai and Guide Hydrological Stations on the upper Yellow River are the inflow and outflow stations of the Longyangxia Reservoir respectively. The two stations represent 30 years' of continuous measuring of water and sediment prior to water impoundment in the reservoir. The runoff and sediment discharge between the two stations demonstrate important aspects of these two issues. Annual records of sediment discharge at Tangnaihai Station after water impoundment and the sediment discharge relationship between the inflow and outflow stations established before water impoundment, allow for the calculation of the yearly sediment discharge not affected by water impoundment in the reservoir at Guide Station. The corresponding years' observed sediment discharge at the station was then were used to estimate the amount of sediment in the reservoir using the difference in values. It is estimated that from October 1986, when the reservoir began to store water, to December 1999, sedimentation volume in the reservoir was 2.98 X 10~8t, or 2.48 X10~8 m~3.