青藏高原西部地质灾害分布特征及背景分析

青藏高原的快速隆起使其地质、地貌和气候发生了剧烈变化,导致崩塌、滑坡、泥石流、岩屑流和冰湖溃坝等地质灾害频发。利用遥感技术对青藏高原西部地质灾害的分布、形成条件进行了研究,对灾害形成的背景进行了探讨。崩塌、滑坡和泥石流主要发育于喜马拉雅山、冈底斯山、喀喇昆仑山及昆仑山的高山峡谷之中;冰湖一般分布于雪线附近;岩屑流发育在雪线之下基岩裸露区的陡坡上;融冻泥流则位于海拔更低的多年冻土和季节性冻土的过渡地带。高原内部的造山带为灾害提供了地形条件;冰川和大气降水为灾害提供了水源;冰川作用和频繁的融冻作用为灾害提供了物源。青藏高原的快速隆升是地质灾害发育的内因,高海拔高寒气候是灾害发育的外因。

Analysis of distribution character and background of geological hazards in western Qinghai-Tibet Plateau

The rapid uplift of the Qinghai-Tibet Plateau cause drastic changes in geology, and form and climate, then the geological hazards such as dilapidation,landslide,mudflow,debris flow and dam breaking of glacier lakes happen frequently. The distribution and forming conditions of geological hazards in western Qinghai-Tibet Plateau were studied by remote sensing, and the hazards evolution background was researched. The dilapidation,landslide and mudflow mainly develop in the canyons of Himalayas mountains,Kailas Range mountains,Qaraqurum mountains and Kunlun mountains. The glacier lakes are usually distributed around the snow line. The debris flow is distributed in steep slope areas under the snow line where the rocks are exposed. Thaw-freezes solifluction is distributed in the area between permafrost and seasonal frozen ground where the altitude is lower than that of the debris flow. The orogenic belt in plateau provide landform conditions, the glaciers and precipitation provide water source, and the glacial action and frequent thaw-freeze action provide a mass of materials for the geologic hazards. The rapid uplift of the Qinghai-Tibet Plateau is the intrinsic factor of the geological hazards, and the high-altitude and extremely cold climate are the extrinsic factors.