An Analysis of Siltation Process and Storage Capacity Change Characteristics of Zipingpu Reservoir since 2008

Wenchuan Earthquake has strongly changed the climate and underlying surface conditions around Zipingpu Reservoir. The frequent occurrence of secondary disasters and changes in the process of runoff and confluence prompted the dynamic adjustment of siltation characteristics in the reservoir area.Based on the measured topographic data since April 2008,the reservoir capacity change and sedimentation evolution process of Zipingpu Reservoir since the earthquake are analyzed. The results show that（1）The M13 cross-section landslide barrier body divides the reservoir area into upper reservoir and lower reservoir. Before 2015,the reservoir area is mainly silted by dead reservoir capacity. After 2015,the upper reservoir regulation capacity decreases,and the lower reservoir dead reservoir siltation accelerates.（2） The earthquake has greatly accelerated the siltation process of the reservoir,and the adjustment of the siltation distribution in the reservoir area is mainly affected by the evolution process of the barrier lake in the upper reservoir.（3） The earthquake has a great influence on the deposition distribution below 850 m and above 871.2 m,and has a little influence on the interval of 850～871.2 m.（4） Below the elevation of 830 m is the main body of siltation in the reservoir area,and the reservoir sections of dam～M13 and M13～M28 are the main locations of siltation.（5） The content of medium and fine sand accounts for 81.57% in the reservoir area,especially the fine sand seriously encroaches on the sediment storage capacity of the reservoir,which will have a negative impact on the benefit and flood control of the reservoir.