祁连山区1961—2014年冻融指数时空变化特征  

Spatial and temporal characteristics of freezing and thawing index in the Qilian Mountains from 1961 to 2014

作　　者：欧安锋 柯贤敏 梁成成 刘鹏[1,2] 王玮[1,2] 牛富俊 高泽永 OU Anfeng;KE Xianmin;LIANG Chengcheng;LIU Peng;WANG Wei;NIU Fujun;GAO Zeyong(School of Water and Environment,Chang’an University,Xi’an 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region,Ministry of education,Chang’an University,Xi’an 710054,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]长安大学水利与环境学院,陕西西安710054 [2]长安大学旱区地下水文与生态效应教育部重点实验室,陕西西安710054 [3]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000

出　　处：《冰川冻土》2023年第1期153-164,共12页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41730640)资助。

摘　　要：冻融指数不仅对冻土研究具有重要意义,而且是反映气候变化的有用指标。利用祁连山区11个主要气象站点的逐日温度观测值计算了1961—2014年的年大气及地面冻融指数,分析了这些指数的统计与分布特征,并通过非参数Mann-Kendall检验法、Sen斜率估计法及相关性分析法分析了年冻融指数的时空变化趋势。结果表明:祁连山区近54年来冻结指数呈显著下降趋势,融化指数呈显著上升趋势,多年平均大气冻结指数、大气融化指数、地面冻结指数和地面融化指数大致分布在994.3~1 540.9℃·d、1 828.2~2 376.6℃·d、744.7~1 287.3℃·d、2 706.0~3 542.6℃·d之间;其气候倾向率分别为-6.5、6.5、-7.7、9.1℃·d·a^(-1)。从西北向东南方向,冻结指数表现出中部高,往东西方向逐渐降低的分布特征,而融化指数则相反;冻融指数除了受海拔和纬度综合影响外,还受台站地的坡向、周边地形、积雪深度以及人类活动等因数的影响。冻融指数时间序列的突变点发生在1994—1995年,与其气温的突变相对应;在突变点以后,大气和地面融化指数的增长速率和地面冻结指数的下降速率增大,大气冻结指数的下降速率减小,且在整个研究期间地面冻融指数的变化率均大于大气冻融指数的变化率,说明地面温度变化对全球变暖更敏感。此外,冻融指数与年平均气温和地面温度的线性关系非常强,且年融化指数在年平均地面温度的构成中所占的比重比冻结指数大。该研究结果对于了解祁连山区气候和冻土变化,进一步计算冻土参数变化和进行祁连山生态环境治理具有借鉴意义。Freezing and thawing index is not only of great significance to the study of frozen soil, but also a useful index to reflect climate change. The daily temperature observation values of 11 national meteorological stations in the Qilian Mountains were used to calculate the annual air and ground surface freezing and thawing indices from 1961 to 2014, and the statistical and distribution characteristics of these indices were analyzed. The temporal and spatial variation trends of the annual freezing and thawing indices were analyzed by nonparametric Mann-Kendall test, Sen’s slope estimation method and correlation analysis method. The results showed that in the past 54 years, the freezing index had a significant downward trend, and the thawing index had a significant upward trend. The annual average air freezing index, air thawing index, ground surface freezing index, and ground surface thawing index were roughly distributed between 994.3 ℃·d and 1 540.9 ℃·d, 1 828.2 ℃·d and 2 376.6 ℃·d, 744.7 ℃·d and 1 287.3 ℃·d, 2 706.0 ℃·d and 3 542.6 ℃·d, respectively. The climatic tendency rates were-6.5 ℃·d·a^(-1), 6.5 ℃·d·a^(-1),-7.7 ℃·d·a^(-1), and 9.1 ℃·d·a^(-1), respectively. From northwest to southeast, the freezing index showed the distribution characteristics of high in the middle and gradually decreasing in the east-west direction, while the thawing index was opposite;in addition to altitude and latitude, freezing and thawing index was also affected by slope aspect, surrounding topography, snow depth and human activities. The abrupt change point of freezing and thawing index time series occurred in 1994—1995, which corresponded to the abrupt change of air temperature;after the abrupt change point, the growth rates of the air and ground surface thawing indices and the decline rate of the ground surface freezing index increased, while the decline rate of the air freezing index decreased. The change rate of the ground surface freezing and thawing index was greater than that of the

关 键 词：冻融指数 全球变暖 时空变化 冻土 祁连山区 

分 类 号：P467[天文地球—大气科学及气象学] P468.021