中巴公路奥依塔克-布伦口段高寒山区泥石流特征

目的]掌握高寒山区泥石流的空间发育特征,进而分析泥石流的诱发机制及危害程度。方法]以实地调查为基础,对中巴公路"三高"(高寒、高海拔、高烈度)地区泥石流分布特征、诱发机制进行研究。结果]该区晚近构造活跃,岩体结构破碎,节理裂隙发育,再加上地处高寒山区,受气候影响,岩体冻融剥落,从而为泥石流的爆发创造物源条件。此外,天山独特的构造特征,山顶存在数百米厚的砂卵石层,保证了物源的补给速率。同时,高陡的地形提供了足够的运动势能,从而集中降水和融雪作用成为泥石流暴发的直接诱因,散粒体因侵蚀揭底、坍塌堵塞、溃决形成泥石流。结论]高寒山区泥石流的形成主要受气候、地形地貌、水力以及地质条件的影响。较普通降雨型泥石流有较大差异,高寒山区泥石流具有明显的高原特性,在物源、水源和地形条件上均有体现。

Characteristics of Debris Flow at Aoyitake-Bulunkou Section of Sino-Pakistan Highway in Alpine Mountains

Objective] To acquire the characteristics of debris flow in alpine mountain in order to analyze the mechanism and the harm degree. Methods] Based on the field investigation, the "three high" distribution of debris flow (cold, high-altitude, high-intensity) along Sino-Pakistan highway, the inducing mechanism were researched. Results] At this area, tectonic movement was active, rock mass structure was broken, joint fracture was developed, besides located in the alpine mountains, and affected by climate and the rock thaw to spall, thus created conditions for the outbreak of the debris flows. In addition, because of the unique structural characteristics of Tianshan Mountain, there were several hundred meters thick of sand and gravel layer to ensure the replenishment rate. High and steep terrain provided sufficient movement potential. Thereby concentrating rainfall and snowmelt role were the direct causes of the outbreak of debris flow. Erosion, collapse blocked and outburst came into being debris flow. Conclusion] The debris flow in alpine mountain was mainly affected by climate, terrain, hydraulic power and geological conditions. With the greater difference from rainfall debris flow, it has obvious plateau characteristics, reflected in the source material, water and terrain conditions.