The Development Condition and Prevention Countermeasure of Glacier Debris Flow in the Aierkuran Gully along the Sino-Pakistan Highway

Abstract

以中巴公路K1601处艾尔库然沟为研究对象，分析艾尔库然沟冰川泥石流的形成条件和起动模式，初步提出合理的防治模式和治理对策。研究发现：艾尔库然沟物源为集中供给型，主要分布在出山口老堆积扇，总方量约为12.7 × 105 m3，其中动储量为36.8 × 104 m3，夏季大量冰川融水沿陡峭岩质山坡(>40˚)倾泻而下，高位势能瞬间转化为强大水流动能，沿大比降沟道(363-176‰)冲刷堆积扇松散物质，在较短时间形成规模较大泥石流，其起动模式可归纳为冲刷起动型和淤塞溃决型两种。结合泥石流形成条件、沟道地形地貌及泥石流危害形式等，提出顺直排泄+梯级降能+主河输移的防治模式，主要工程措施包括铅丝笼浅槛群和堆石导流堤等。研究结果可为中巴公路沿线冰川泥石流的防治提供参考依据。 The Aierkuran gully locating on the Sino-Pakistan Highway K1601 was selected as the case study. The formation conditions and startup mode of the glacial debris flow were analyzed, and a reasonable and effective prevention measure was proposed preliminarily. The results show that the material sources of debris flow in the Aierkuran gully belonged to the central supplying type, and are mainly distributed in the old accumulation fan out of the mountain. The total volume of material sources is about 12.7 × 105 m3, and the dynamic storage is about 36.8 × 104 m3. The large numbers of glacier melt water poured down along the steep rock slope (>40˚) in summer. The high potential energy is transformed into strong flow kinetic energy immediately, which flushes the loose materials of the alluvial fan along the steep slope (363-176‰) gully, and further a large-scale debris flow would be triggered. The startup mode can be summed up as scour-start type and blockage-outburst type. Combining with the formation conditions, the gully topography and the destruction form, etc., the control mode of “direct and straight draining + cascade energy lowering + main river transporting” is suggested and the main control measures included the ground sills and the enrockment diversion dike. The results will provide the reference base for preventing the glacial debris flow along the Sino-Pakistan Highway.