SEISMIC HAZARD ASSESSMENT FOR DAIGUSI RESERVOIR AND ITS SURROUNDING AREAS ASSOCIATED WITH BAILONG RIVER DIVERSION PROJECT

The Bailong River Diversion Project is a proposed major strategic project in China,and the Daigusi Reservoir is the water source hub of this project. The Daigusi Reservoir and its surrounding areas(the study area of this paper) are surrounded by many active faults and frequent major earthquakes. Therefore,a reliable seismic hazard assessment for this study area is urgently needed to protect the area's engineering construction and operation. Because traditional seismic assessment methods lack solid physical basis,we adopt a new method based on earthquake physical prediction to evaluate the seismic hazard of the study area. The results of this study show that the seismic hazard of the study area in the next 100 years mainly originates from the next M_S8.5 landmark earthquake in the Haiyuan seismic zone. Based on the seismicity,seismogenic potential and distribution characteristics of faults,we pre-judge the possible seismogenic faults and epicenters of this landmark earthquake; using the seismic intensity decay relationship,we calculate the seismic intensity generated from this earthquake with different epicenters. To ensure the long-term safety of the water source hub of Daigusi Reservoir associated with Bailong River Diversion Project,we suggest that the seismic intensity of the study area should not be less than 8 degrees.