丹江口水库二期工程诱发地震强度预测

丹江口水库作为南水北调中线工程的源头，分两期开发：在初期工程中，水库蓄水后库区地震活动加强：水库续建工程计划提高水位至170m，水位的提高可能引发新的地震活动进行丹江口水库二期工程诱发地震危险性分析和预测震级对水库的防灾和减灾具有十分重要的意义。基于诱发地震强度评估理论，分析水库诱发地震的主要影响因素，运用地球动力学方法计算丹江口水库一期工程库区应变能和释放的地震能，推导出能量转换系数，并在此基础上预测丹江口水库提高水位后诱发地震的可能性预测结果表明，水库续建工程诱发地震的可能性很大，主要发震部位可能位于丹库峡谷形库段和库岸碳酸盐类岩石与其它类岩石的交界部位.提高水位后，丹江口水库诱发地震的最大震级为4．5级.

Strength Evaluation of Induced Seismicity in the Second Phase of Project of Danjiangkou Reservoir

As the head for south-to-north water diversion project, Dandjiangkou reservoir is divided into two developments. In the initial project, the seismic activity in reservoir region strengthened after impoundment. The subsequent project of Danjiangkou reservoir planned to raise water level to 170 m. With the water level change the new earthquakes will possibly emerge. So estimating the magnitude of reservoir induced seismicity is profound to the quakeproof and reducing disaster of reservoir area. Based upon the theories of strength evaluation of reservoir induced seismicity (RIS) and analyzing the main influence factors upon RIS, geodynamics method is applied to calculate the strain energy and released seismic energy of Danjiangkou reservoir area in the first phase of project and deduced the coefficient of energy conversion, which is used to evaluate the seismic possibility and magnitude after the water level of Danjiangkou reservoir rises. The result is that the likelihood of inducing seismicity is high and the hypocenters are potentially located in the places of Danjiang reservoir that is gorge-shaped and where carbonate rocks march with other rocks and that the magnitude is no more than 4.5 after the water level increases.