Abstract: On the basis of histrical earthquake data and the observations two grey forecasting models for the next seismic activity period and the maximal magnitude of earthquakes which may occur within the period are constructed by means of grey system theory.The two models have predicted that the next seismic activity period will last for 79a, and that the maximal magnitude of earthquakes occurring within the period would not be more than 5.2.The results provide an imortant evidence for assessment of earthquake risk and precaution of disasters in the Three-Gorge area.

Key words: Grey theory, Seismicity peak period, Magnitude, Changjiang Three-Gorge

摘要： 根据历史地震记载和现今地震观测数据,运用灰色系统理论,建立了长江三峡及邻区下一个地震活跃期及活跃期内可能发生的最大地震的震级的灰色预测模型。预测结果表明,下一个地震活跃期将持续79a,活跃期内的最大地震震级不会超过5.2级。这对三峡地区地震问题的评价与防患提供了重要的依据。

关键词: 灰色理论, 地震活动高峰期, 震级, 三峡地区