Snow disaster characteristics in Palongzangbu River Basinand mitigation countermeasures for road engineering

The Palongzangbu River Basin contains the highest number of maritime province glaciers in China. There are 130 glacial lakes, 64 snow avalanche sites and 28 glacial debris flow gullies distributed within the basin. Snow disasters play a controlling role in the Sichuan-Tibet Highway construction, due to the terrain’s special characteristics of high altitude and large height differential. Segmentation mitigation countermeasures for the Sichuan-Tibet Highway are presented based on snow disaster severity level and damage mode of the road. In the Ranwu to Midui section, snow avalanches are regional disasters, so the line should be placed in sunny slopes. In the Midui Gully to Yupu section, the line should be placed in shady slopes and at higher elevations to reduce the risk of glacial lake outburst. In the Yupu to Guxiang section, all three snow disasters are minimal. In the Guxiang to Tongmai section, glacier debris flows are the major threat, thus the road should be placed in shady slopes.

帕隆藏布流域沟槽型雪崩发育特征及分布规律研究

采用遥感手段解译帕隆藏布流域9106处沟槽型雪崩灾害点,通过应用GIS方法结合ALOS高精度数字地形数据,统计分析了帕隆藏布流域沟槽型雪崩的分布规律,并对典型沟槽雪崩的地形地貌及结构等发育特征进行了研究。结果显示:(1)帕隆藏布流域沟槽型雪崩发育明显的积雪区、运动区和堆积区,具有雪崩量大、运动速度快、冲击能量大、破坏力强等特征。(2)研究区沟槽型雪崩灾害分布呈从北到南、从东向西降低的趋势,集中分布在高海拔、森林覆盖率较低、狭窄陡峻的河谷岸坡上。(3)研究区沟槽型雪崩灾害分布在海拔3200∼5700 m内,坡度在25°∼50°之间,坡向在60°∼132°、222°∼288°范围内。