南水北调西线工程通天河－雅砻江调水区若干冻土环境问题研究

Some Permafrost Environment Problems with Respect to the Western Channel Project of the South-North Water Diversion in the Region of the Tongtian-Yalong Rivers, China

调水区多年冻土划分为３个区，冻土面积为１１×１０４ｋｍ２左右，约占全区面积的７２．４％。受全球气候变化及人类经济活动的影响，区内多年冻土处于退化状态。在全球气候持续变暖的情况下，未来５０ａ内，目前厚度小于１０ｍ的多年冻土和岛状多年冻土将消融殆尽，多年冻土面积将减少约１５％，冻土下界上升１５０～２００ｍ；气候变暖，使得季节性冻土层变薄，某些地段的多年冻土消失或变为深埋藏多年冻土等，则可降低工程造价。

In this paper, some permafrost environment problems and the trend of permafrost degeneration are discussed with respect to the western channel project of the south-north water diversion in the region fo the Tongtian-Yalong Rivers. Based on Lansad 2, 5 MSS, TM data and air photo images, combined with ground investigation, the spatial distribution characteristics of the permafrost are studied. The area of permafrost is about 11×10 4 km 2 ,72.4% of the studied region. It is inferred that the area of permafrost will reduce 15% and the lower limit of permafrost will rise 150～200 m in the 50 years to come.