摘要
根据4个冻土长期定位观测场地温资料分析，西大滩观测场深12～20m段地温升高0．2～0．3℃，多年冻土层由下向上减薄4～5m；昆仑山垭口观测场深6～15m段地温升高0．2～0．4℃；66道班观测场内天然场地地温高于人工沙场0．1～0．2℃；可可西里观测场内天然植被场地地温普遍高于裸露场地约0．2℃．监测结果表明，影响高原多年冻土发育的因素多具有两重性，地表沙层和植被同样具有升高地温和降低地温的作用这些因素与冻土相互作用，它们可以相互转化，在不同条件下起不同的作用．因此，要用动态变化的观念研究、认识和评价多年冻土及其工程地质特性.
Ground temperature monitored at four observation sites in permafrost regions on the Tibetan Plateau are analyzed. It is found that the ground temperature at the depth of 12~20 m increased 0.2~0.4K and the permafrost thickness decreased 4~5 m from the base in Xidatan Site from 1975 to 1989; and the ground temperature at the depth of 6~15 m increased 0.2~0.4 K in Kunlun Pass Site from 1982 to 1997. Contrast observations show that a sand cover, 15-20 cm in depth, can result in a ground temperature decrease of 0.1~0.2 K in MS No. 66 Site; and a remove of vegetation can result in a ground temperature decrease of some 0.2 K in Hob Xil Site. The monitor demonstrates that many factors that control permafrost developing have duality, e.g., sand and vegetation are able to increase or decrease the ground temperature. These factors, in company with permafrost behaviour, play different roles under different conditions. Therefore, it is necessary to study, understand and evaluate permafrost and its engineering geological properties taking a viewpoint of dynamic variation.
出处
《冰川冻土》
CSCD
北大核心
1999年第2期159-163,共5页
Journal of Glaciology and Geocryology
基金
中国科学院冰冻圈动态变化基础研究项目!Kj-b-2-100
国家与中国科学院青藏高原研究项目
中国科学院重点基金!KZ952-S1-215
