关键词: 西藏, 那曲地区, 湖泊动态, 气候变化响应

Abstract: Out of the 1976,1990,2000 and 2010 remote sensing images of Naqu region of Tibet,information was extracted about dynamic variations of alpine lakes bigger than one square kilometer in water surface,therein.And correlation analysis was done of the information with the meteorological data from 1966 to 2010 available from the nine meteorological stations in the region to explore responses of the dynamics of the lakes to changes in the climate.Results show that there were a total of 469 lakes(bigger than 1 km² in water surface),amounting to 16 841.93 km² in total area in 2010.In the past 35 years,the lakes increased by 3 505.12 km² or 26.28% in total area(especially in the period of 2000-2010 by 18.18%) and by 96 or 25.73% in number of lake(especially in the period of 1990-2000 by 13.38%).The area of Lake Selin Co increased from 1 648.61 km² in 1976 to 2 332.55 km² in 2010,an increase rate of 41.49%,and exceeded Lake Nam Co in area,becoming the largest saline lake in Tibet.In the past 45 years,Naqu region witnessed a general rising trend in annual mean air temperature,annual mean highest air temperature,annual mean lowest air temperature,annual mean precipitation and annual mean relative humidity,but a reverse trend in annual mean evaporation,suggesting that the climate in that region is changing towards warm and wet,and the change in temperature is the most remarkable,increasing by 2.27 ℃ from 1966 to 2010.The climate tendency rate reached 0.51 ℃·(10 a)^-1.The gray correlation degree analysis of dynamic changes in lakes with the meteorological factors shows that the the increase in ice-snow melt-water triggered by the rise of the air temperature,the increase in precipitation,the increase in relative humidity and the decrease in evaporation were the main causes of the increase in lake area and number of lakes in Naqu of Tibet over the past 35 years.Regression of the meteorological elements with changes in lake area shows they are linearly related. 

Key words: Tibet, Naqu region, dynamics of the lake, response to climate change