论文部分内容阅读
汶川8级地震直接引发了大量的崩塌、滑坡等次生山地灾害,为泥石流提供了丰富的物质来源,灾后遇高强度降水,已引发大规模的次生泥石流灾害,严重威胁灾民安置点和灾后重建场址。以北川苏保河流域为例,分析了泥石流形成的地形地貌条件、松散固体物质条件和降水条件,总结了苏保河流域泥石流的危害和特征,在此基础上,通过形态调查法和雨洪法对泥石流流量的计算进行了对比分析。结果表明:地震后苏保河流域演变为泥石流多发区域,泥石流将会危害人民生命财产安全、灾后抢险救灾公路和人类生存环境;苏保河流域泥石流具有呈群发性,危害范围大、密度高,搬运能力强、激发泥石流的雨量相对偏小、多灾种复合性的特征;地震后,由于强震引发松散固体物质的剧增、地表植被破坏引起径汇流条件的变化、沟道性质的变化及沟道内形成的多级堵塞,使泥石流的规模增大。
The Wenchuan Ms8.0 earthquake triggered a large number of secondary mountainous landslides such as landslides and landslides. It provided a rich source of material for debris flow. After the earthquake, high-intensity precipitation had triggered large-scale secondary debris flow hazards that seriously threatened the resettlement sites and post-disaster victims Reconstruction site. Taking Beichuan SuBao river basin as an example, this paper analyzes topography, loose solid material conditions and precipitation conditions caused by debris flows, summarizes the damage and characteristics of debris flow in the SuBao river basin, and on this basis, through the morphological investigation method and rain flood method, The comparative analysis of the calculation. The results show that after the earthquake, the Su Ba River basin evolved into a multiple debris flow area, the debris flow will endanger people’s life and property safety, disaster relief roads and human survival after the disaster; debris flow in the Su Bao River basin with mass, hazard range, high density, After the earthquake, due to the sharp increase of loose solid matter caused by the strong earthquakes, the destruction of surface vegetation caused the change of diameter confluence, the change of channel property and the formation of Multi-level blockage, so that the scale of debris flow increases.