构造型水库诱发地震震级预测与探讨

Magnitude Prediction and Discussion of Tectonic Reservoir-induced Earthquake

国内外大量水库发生过不同震级的水库诱发地震,给社会经济环境和生态环境等都造成了不同程度的损失,自20世纪70年代以来,国内学者从不同角度对水库诱发地震的诱发原因和预测方法展开了研究。在前人研究的基础上,对水库诱发地震基本特征和诱发主要因素进行了分析、研究,探索性提出了构造水库地震影响因素的隶属函数,该构造函数综合考虑了对水库规模、构造类型、构造活动性、地层岩性等因素对水库诱发地震的影响,并构建了新的水库诱发地震数学模型对国内外100多座水库诱发地震震例进行计算。经对比分析,发现采用本模型计算的水库诱发地震震级与各水库实际地震震级相接近,可见利用该数学模型预测水库诱发地震震级是基本可行的,希望能为构造型水库诱发地震预测与防治提供一点启示;此外,还发现地震动参数对水库诱发地震的震级贡献相对较大,但水库规模对震级贡献相对较小,特别是水深超过20 m时,水库规模导致的震级差异不明显。

A large number of reservoir-induced earthquakes of different magnitudes have occurred at home and abroad,causing varying degrees of losses to the local economy,social environment and ecological environment.Since the 1970s,scholars from various countries have conducted research on the causes and prediction methods of reservoir-induced earthquakes from different perspectives.On the basis of previous studies,the basic characteristics and main factors of reservoir-induced earthquakes are analyzed and studied.The membership function of the influencing factors of tectonic reservoir-induced earthquake is proposed tentatively,which comprehensively considers the influence of reservoir scale,tectonic type,tectonic activity and rock lithology on reservoir-induced earthquake.A new mathematical model for reservoir-induced earthquakes is constructed,and calculations are performed on more than 100 cases of reservoir induced earthquakes in the world.Through comparative analysis,it is found that the reservoir-induced earthquake magnitude calculated using this model is close to the actual earthquake magnitude of various reservoirs,indicating that it is basically feasible to use this mathematical model to predict the magnitude of reservoir-induced earthquakes.It is hoped that this can provide some enlightenment for the prediction and prevention of tectonic reservoir-induced earthquakes.Additionally,it is found that the ground motion parameters make a relatively large contribution to the magnitude of reservoir induced earthquake,while the contribution of reservoir scale is relatively small,especially when the water depth exceeds 20m,the difference in magnitude caused by reservoir scale is not significant.