帕隆藏布流域沟槽型雪崩发育特征及分布规律研究

Study on the Developmental Characteristics and Distribution Pattern of Grooved Avalanche in Palongzangbu River Basin

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。

In this paper,remote sensing interpretation was used to obtain 9106 sites of grooved avalanche disas⁃ter in the Palongzangbu River Basin.The distribution pattern of grooved avalanche was statistically analyzed by using GIS method with ALOS high-precision digital topographic data,and the developmental characteristics of the topography,geomorphology and structure of the typical grooved avalanche were studied as well.The results showed as following.(1)The grooved avalanche in the Palongzangbu River Basin has obviously developed snowpacked areas,movement areas and accumulation areas with characteristics of large avalanche volume,fast move⁃ment speed,high impact energy and strong destructive force.(2)The distribution pattern of grooved avalanche di⁃sasters shows a decreasing trend from north to south and from east to west,and mainly distributed in the moun⁃tain gullies with high elevation,narrow river valleys,and low forest coverage.(3)The grooved avalanche disasters in the study area are distributed within 3200~5700 m above sea level and slopes ranging from 25°to 50°,slope aspect ranging from 60°to 132°and 222°to 288°.