Analysis About Ertan Reservoir's Sedimentation And Storage Conditions

Ertan Hydropower Station,located in the downsteam of Yalong River,Panzhihua city.It is the first plant of the 21 Yalong River cascade projects.The normal storage level is 1200m.The reservoir capacity is 5.8 billion m~3 and the dead water level is1155m.The adjustable capacity is 3.37 billion m~3 and the reservoir is seasonal regulating.The plane shape of the reservoir area is strip shape,which is a river type reservoir.Influences of reservoir sedimentation are mainly in the following aspects:first is the occupation of regulation capacity,which reduces the utilization efficiency;second is the deposition of the end reservoir rise,which increases backwater level,reservoir inundation,and immersion loss;third is the changing backwater make the mainstream shifting to influence shipping.In addition,the effect of sediment in front of the dam will increase the pressure on dam,affecting the normal operation of the inlet.Also the sediment get into the diversion system will increase the wear of the diversion buildings and turbine.Therefore,the research and analysis of characteristics of sediment in Ertan reservoir are very necessary.It provides the distribution of sediment accumulation in Ertan reservoir,the reliable storage characteristics for reservoir operation and optimal scheduling and the full play to the comprehensive benefit of the reservoir.In this paper,the research is based on Ertan reservoir geological investigation and result of multiple reservoir sediment section measurement.The research topic is the reservoir sedimentation and storage conditions.The basic materials include the analysis of the survey data from Ertan reservoir sediment source,the actual situation of reservoir sedimentation,several aspects of capacity changes to acquire the reservoir sedimentation status.Through the characteristics,law and regulation storage loss rate of Ertan reservoir operation since it operating,the sedimentation influence in the reservoir operation mode and the effective capacity are investigated.Furthermore,the corresponding measures and reduce sediment deposition on the regulating capacity are researched to meet the needs of reservoir optimal operation and to facilitate the long-term play efficiency.Combined with the examination results,it explores the basic law of the Yalong river sediment passage,analysis the impact of reservoir landslide and debris flow in the reservoir development,provide effective measures to reduce and slow deposition especially effective capacity loss solving measures.Otherwise combined with the basic river characteristics and the river flow and sediment conditions,it provides the long-term point view of the reservoir use.It provides a strong basis for project management,reservoir operation,and flood control and so on.It also can provide certain reference and guidance for the same type of high arch dam reservoir long-term safe and stable operation.With limited level,the author hopes this paper is helpful to the of the hydropower project management.