采用遥感、构造地貌测量、物探、大地切片、钻孔、探槽和测年技术研究1679年三河-平谷8级地震发震断层南夏垫断裂晚第四纪10万年以来的滑动速率曲线、完整的古地震序列及地震危险性。采用高精度浅层地震探测、小孔距钻孔探测、大地切片技术、大型探槽探测开挖和测绘、系统密集取样和测试，揭露出地表以下20多米范围内断层变形和相关沉积层的精细结构剖面，进行详细的层序分析和对比，绘制断层两盘沉积速率-时间曲线、断层位错量-时间曲线、计算绘制出滑动速率-时间曲线。根据古地震识别标志和分析技术，分辨出完整的古地震事件及各次事件的判断标志、位错幅度、变形特征和相关沉积变化。根据测年结果和古地震定年技术，获得10万年以来详细的古地震事件-时间（M-T）图、复发间隔-时间（R-T）图、复发时间-位错幅度（R-D)图等，计算平均复发间隔和变异系数。再分别依据震级可预测模型和时间可预测模型计算该断裂的地震危险性。

The Xiadian fault in Beijing Plain is the seismogenic fault of the Sanhe-Pinggu M=8 earthquake occurred in 1679. The slip rate curve and complete paleoearthquake sequence within 100ka, as well as the seismic risk of Xiadian fault will be studied in this proposed project. The study will comprehensively use a group of active tectonic studying methods which mainly include the high resolution shallow artificial seismic exploration, small dot pitch drilling exploration, geo-slice method, large paleoearhthquake trench, surveying and maping method, systematic and intensive sampling and Quaternary geologic dating. Fine structure of the fault and the related deposition within more than 20m can be well revealed.Detailed analysising and comparising the stratigraphic sequences of both wall of the fault will be made. The Diagrams of deposition rate－time, offset-time, slip-rate-time，will be calculated and plotted. All paleoearthquake events should be recognized with the judgment and analysis techniques. The marks, offsets, deformation features and related deposition changes can be also difined from the profile. The time of each event can be difined by dating result. The detailed diagrams or curves of paleoearthquake event-time, recurrence interval-time, recurrence interval-offset, will be made, the average recurrence interval and the coefficient of variation can be calculated. In the end, the seismic risk of the this fault will be assessed with the model of magnitude predictable model and time predictable model.