中尼公路是西藏西南部经济发展的动脉，沿线泥石流灾害严重威胁到线路的正常运营，本研究根据航空照片和卫星图象解译结果，结合现场踏勘校对，深入地研究了沿线700km范围内的环境背景条件和泥石流活动规律，确定沿线有泥石流沟842条，其中沟谷型泥石流沟474条，在公路一侧直接危害公路的沟谷型泥石流241条，深入地探讨了这一高原特殊环境下的泥石流活动特性；为公路部门提供了泥石流防治方案，成为线路整治改建的依据。

The China-Nepal Highway, located in southwest Tibet, is vital not only to the economical development of TIbet, but also to national defense in China. Because of the complex of gologic structures, complicated stratigraphic and lithologic characters, intensive neotectonic movements, a great variety of hydrothermal conditions and strong glacial actions, all kinds of natural hazards occur widely on both sides of the highway, such as debris flows, land-slides, avalanches, etc. The above hazards often threaten the transportation safety of the high-way, and severely restrict local economic development. Among all the mountain hazards, debris flow is the major one. In this paper, based on historical data, the interpretation of aerial photos and satellite images (TM and SPOT), as well as field investigation, the environmental background of the study area, especially the geological structure, lithology, plant and soil, hydrography and climate are analyzed in detail. Some 842 debris flow gullies are identified in this area, of which 474 have clear channels and 241 develop on both sides of the highway. The mouths of debris flow gullies are located at elevations between 1810 m and 5000 m m, of which more than 80% range between 3500 m and 4500 m. The drainage basins of debris flow gullies cover an area between 0.2-161 km~2, especially, 75% of which with an area between 1.0-5.0 km~2. According to their genesis, debris flows in this area can be divided into 3 types: glacial, glacial lake burst and rainfall. Of the 241 debris-flow gullies, 205 (85.1%) are of rainfall debris flows and 26 (10.8%) are of glacial debris flows.