Analysis about the influence on the thermal regime in permafrost regions with different underlying surfaces  

作　　者：QiangQiang Pang Lin Zhao YongJian Ding ShuXun Li 

机构地区：[1]Cryosphere Research Station on Qinghai-Xizang Plateau, Cold and Arid Regions Environmental and Engineering Research In- stitute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China [2]State Key Laboratory of Cryospheric Sciences, CoM and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China

出　　处：《Research in Cold and Arid Regions》2010年第3期203-211,共9页寒旱区科学（英文版）

基　　金：supported by a grant from the National Natural Science Foundation of China (No. 40830533; No.40871037);the Major State Basic Research Develop-ment Program of China (973 Program) (No. 2005CB422003;No. 2007CB411505; No. 2007CB411505)

摘　　要：In the last several decades, the underlying surface conditions on the Qinghai-Tibet Plateau have changed dramatically, causing permafrost degradation due to climate change and human activities. This change severely influenced the cold regions environment and engineering infrastructure built above permafrost. Permafrost is a product of the interaction between the atmosphere and the ground. The formation and change of permafrost are determined by the energy exchange between earth and atmosphere system. Fieldwork was performed in order to learn how land surface change influenced the thermal regime in permafrost regions. In this article, the field data observed in the Fenghuo Mountain regions was used to analyze the thermal conditions under different underlying surfaces on the Qinghai-Tibet Plateau. Results show that underlying surface change may alter the primary energy balance and the thermal conditions of permafrost. The thermal flux in the permafrost regions is also changed, resulting in rising upper soil temperature and thickening active layer. Vegetation could prevent solar radiation from entering the ground, cooling the ground in the warm season. Also, vegetation has heat insulation and heat preservation functions related to the ground surface and may keep the permafrost stable. Plots covered with black plastic film have higher temperatures compared with plots covered by natural vegetation. The reason is that black plastic film has a low albedo, which could increase the absorbed solar radiation, and also decrease evapotranspiration. The ＂greenhouse effect＂ of transparent plastic film might effectively reduce the emission of long-wave radiation from the surface, decreasing heat loss from the earth＇s surface, and prominently increasing ground surface temperature.In the last several decades, the underlying surface conditions on the Qinghai-Tibet Plateau have changed dramatically, causing permafrost degradation due to climate change and human activities. This change severely influenced the cold regions environment and engineering infrastructure built above permafrost. Permafrost is a product of the interaction between the atmosphere and the ground. The formation and change of permafrost are determined by the energy exchange between earth and atmosphere system. Fieldwork was performed in order to learn how land surface change influenced the thermal regime in permafrost regions. In this article, the field data observed in the Fenghuo Mountain regions was used to analyze the thermal conditions under different underlying surfaces on the Qinghai-Tibet Plateau. Results show that underlying surface change may alter the primary energy balance and the thermal conditions of permafrost. The thermal flux in the permafrost regions is also changed, resulting in rising upper soil temperature and thickening active layer. Vegetation could prevent solar radiation from entering the ground, cooling the ground in the warm season. Also, vegetation has heat insulation and heat preservation functions related to the ground surface and may keep the permafrost stable. Plots covered with black plastic film have higher temperatures compared with plots covered by natural vegetation. The reason is that black plastic film has a low albedo, which could increase the absorbed solar radiation, and also decrease evapotranspiration. The ＂greenhouse effect＂ of transparent plastic film might effectively reduce the emission of long-wave radiation from the surface, decreasing heat loss from the earth＇s surface, and prominently increasing ground surface temperature.

关 键 词：permafrost underlying surface thermal regime Qinghai-Tibet Plateau 

分 类 号：P404[天文地球—大气科学及气象学] U213.14[交通运输工程—道路与铁道工程]