【摘要】 "5.12"汶川地震后,龙溪河碱坪沟流域内堆积了大量的松散固体物质,成为参与泥石流形成的主要物源。碱坪沟于2009—2010年先后3次暴发大规模泥石流灾害。通过对碱坪沟的地形、水源和物源条件的分析发现,该流域地形和水源条件满足泥石流形成的条件,且在地震前后未发生显著变化,而物源条件已经成为影响该区域泥石流形成与发展的主要因素。基于流域物源量与物源固结效应的研究结果表明,在5a内碱坪沟泥石流灾害较活跃,可能暴发大规模泥石流灾害。5～10a后,在降雨条件不发生较大变化以及不暴发大地震的情况下,流域内泥石流规模和频率会逐渐减小,只有在低频率暴雨作用下才可能暴发大规模泥石流灾害。更多还原

【Abstract】 After the "5·12" Wenchuan Earthquake,plenty of loose soil materials accumulated in Jianping Basin of Longxi River,which is the main source material for debris flows initiation.Three large-scale debris flows occurred in Jianping Gully in 2009 and 2010.In contrast with the pro-earthquake conditions,the terrain and rainfall have not changed a lot and are appropriate for the initiation of debris flow,so loose materials can be regarded as the most significant impact factor for the debris flow characteristics and its development trend.The results based on the analysis of loose materials and its consolidation impact shows that debris flows in Jianping Gully will occur frequently in 5 years.The possibility of catastrophic debris flow will be high.In the next 5~10 years,the frequency and scale of debris flows in Jianping Gully will decline if there is no significant change for the rainfall and no strong earthquake,while large-scale debris flows can also occur under extremely rainfall with low frequency.更多还原