青藏铁路沿线风沙灾害特点及成因分析  

Sand Hazard Characteristics and Genetic Analysis along the Qinghai-Tibet Railway

作　　者：安志山[1] 张克存[1] 屈建军[1] 牛清河[1] 张号[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室,敦煌戈壁荒漠生态与环境研究站,甘肃省风沙灾害防治工程技术研究中心,兰州730000

出　　处：《水土保持研究》2014年第2期285-289,共5页Research of Soil and Water Conservation

基　　金：国家重点基础研究发展计划(973计划)专题(2012CB026105-2);中科院寒旱所青年基金

摘　　要：随着全球变暖,青藏高原作为全球独特的地域单元,其反应极为敏感,且随着青藏铁路的建成通车,铁路沿线风沙灾害日趋严重。通过野外考察,分析总结青藏铁路沿线风沙灾害特点,并揭示其成因。随着气温升高,冰川萎缩、雪线上升、冻土退化、高寒草甸沙化,释放了内部赋存的碎屑物质;同时,气温升高导致冻融作用增强,地表土壤结构更易离散分解,形成更多的碎屑物质。其次,青藏高原地处西风带,终年盛行西风,区内起沙风向单一,属于高风能地区,为风沙活动提供了充足的动力条件。再次,青藏高原属于典型的"风旱同季",风水蚀交替影响,为沙害发生奠定了有利基础。第四,青藏铁路建成通车,铁路沿线流场发生改变,打破局地原有输沙平衡,形成易于沙粒沉降的有利环境,为风沙灾害的发生提供地点。综上四点,为铁路沿线风沙灾害的发生提供了便宜条件,最终导致风沙灾害的发生。The Tibet Plateau is the unique geographical umt in the world. It has significant response to global warming. With the completion of the Qinghai-Tibet railway, the railway sand disasters had become increasingly serious. After the field investigation, the authors revealed the characteristics of sand damages. With the temperature rising, the glaciers are shrinking. The snow-line is rising. The permafrost is degeneranng. The plateau meadow and grassland have the desertification. Therefore, the original fixed detrital material relea- ses. Second, the freeze-thaw cycles enhanced, the surface soil structure decomposed and formed more detrital material. So, the sand sources increased. According to climate data, the windy period combing with an arid seasonal climate increased the risk of blowing sand in this area. It rarely snows in winter and the land surface is usually bare. Meanwhile, the wind is very strong and unidirectional along the Qinghai-Tibet Railway and the dominant direction is west. And it belongs to high-energy wind environment along Qinghai-Tibet Rail- way. Predominant wind has a unidirectional characteristic. The dominant directions of sand transport are westerly in the observed period. Third, the Qinghai-Tibet Railway opened to traffic and resulting in railway flow field change, breaking the local original sediment balance, forming sand sedimentation environment easily. Therefore, the sand damages readily occur because of the factors mentioned above.

关 键 词：青藏高原 全球变暖 风沙灾害 

分 类 号：P425.55[天文地球—大气科学及气象学] U216.419.2[交通运输工程—道路与铁道工程]