地震扰动区小流域地质灾害(滑坡、崩塌、泥石流)风险区划研究主要涉及两方面的问题:①地震扰动区小流域滑坡泥石流与一般地区的滑坡泥石流有什么差异?②这种特定环境的滑坡泥石流风险区划与一般地区风险区划有什么不同?根据这两个关键命题讨论了汶川地震灾区都江堰白沙河小流域滑坡泥石流风险区划问题,认为在地震扰动区的一个独立地貌单元小流域中,滑坡泥石流比非地震区小流域的分布数量更多,范围更广,规模更大。尤其在后期降雨条件下发生频率更高,潜在危险性更高。所以在危险度区划阶段必须结合地震因子,评价与地震动因素的相关性,突出地震动的破坏作用。易损度区划阶段应该考虑承载体的抗震因子。风险区划模型与一般地区模型基本一致,而差别在危险度区划阶段结合了地震因素的影响。

Geological hazards risk zonation at small watershed scale in seismic disturbed area mainly involves two issues. One is about the difference between the hazards in the small watershed of seismic disturbed area with them in the normal place. The other is about the difference between the geological hazards risk zonation in the particularenvironment with the general area. We discussed landslide and debris flow risk zonation of Baishahe watershed in Wenchuan Earthquake disturbed region according to these two key issues. It considered that landslide and debris flow distributed more largely and widely in a separatedgeomorphological unit of small watershed than in the none-seismic area. They would occur in a higherfrequency and have more potential hazards in the rainfall condition especially. So,in the stage of hazard zonation,it should combine with the seismic factors,evaluate the correlation with them,and highlight the damage effect of seismic vibration. Vulnerability zonation should consider hazard bearing body’s seismic factors. However,risk zonation model is consistent with general area evaluation model,only considering the seismic factors in the hazard zonation stage.