1960-2015年新疆塔什库尔干河谷季节性冻土对气候变化的响应

Response of seasonal frozen soil to climate change in Taxkorgan River Valley of Xinjiang duing 1960-2015

利用1960-2015年新疆塔什库尔干河谷季节性冻土的冻结始日、冻结终日、年冻结日数、年累积冻土厚度、最大冻土深度等特征指标资料,采用气候倾向率、气候突变、气候变化趋势的持续性等方法,分析近56 a该地区季节性冻土的年际、年代际变化特征。研究发现:(1)在全球变暖的背景下,1960-2015年新疆塔什库尔干河谷气温变化亦呈上升趋势,升温趋势的持续性较强,升温幅度0.03℃·a^(-1)、0.29℃·(10 a)^(-1)、0.74℃·(30 a)^(-1)。(2)在1960-2015年期间,该地区季节性冻土呈退化趋势,具体表现为;冻结始日推迟,冻结终日提前,年冻结日数减少,年累积冻土厚度减小,最大冻土深度减小。(3)在1960-2015年期间,该地区季节性冻土持续退化趋势持续性强。(4)1960-2015年新疆塔什库尔干河谷季节性冻土对气温变暖的具体响应呈现为退化状态。(5)按气候升温率Gt;0.034~0.046℃·a^(-1)计算,在气候变暖背景下,该地区季节性冻土到2050年(较2000年)的冻结始日将推迟12~15 d、年冻结日数将减少21~27 d、年累积冻土厚度将减少36.3%~46.7%。

Based on the existing research of domestic and foreign scholars,this study focused on the response of seasonal frozen soil to climate change in Taxkorgan River Valley of Xinjiang by using climate diagnostic analysis. The characteristics and trends of seasonal frozen soil in this area were revealed during 1960-2015. The facts of seasonal frozen soil degradation are proved by the objective data in this region. What＇s more,this paper also predicted the state of seasonal frozen soil when this change trend lasted until 2050. Characteristic parameters including the beginning date of seasonal frozen soil,the ending date of seasonal frozen soil,the number of annual frozen days,the accumulate thickness of the frozen soil,the maximum depth of frozen soil,and so on,and the analyzing methods including climate tendency rate,abrupt climate change and climate change trend were used for analyzing the variation characteristics of seasonal frozen soil in the inter annual and the decade years. The results show as follows：（1）under the background of global warming,the temperature change showed an upward trend in Taxkorgan River Valley of Xinjiang during 1960-2015,it was a strong warming trend,of which the heating rate were 0.03 ℃·a^-1,0.29℃·（10 a）^-1,0.74 ℃·（30 a）^-1;（2）during the period of 1960-2015,the seasonal frozen soil in the area was degraded,showing that the beginning date of seasonal frozen soil was postponed,the ending date of seasonal frozen soil was advanced,the number of annual frozen days was reduced,the accumulate thickness of seasonal frozen soil was reduced,and the maximum depth of seasonal frozen soil was reduced;（3）during the period of 1960-2015,the degradation trend of seasonal frozen soil in this region had strong sustainability;（4）during the period of 1960-2015,the specific response of seasonal frozen soil to global warming in Taxkorgan River Valley of Xinjiang showed the state of degradation;（5）assume that the climate warming rate（GT）was the annual 0.034-0.046 centigrade,under the background of climate warming,the beginning date of seasonal frozen soil would be postponed for 12-15 days,the number of annual frozen days would reduce 21-27 days,the accumulate thickness of seasonal frozen soil would reduce by 36.3%-46.7% in 2050（comparison with 2000）.