海南地区冻土初终日的变化特征分析

Analysis of Variation Character in Frozen Soil First and Last Date in Hainan Region

利用1961-2017年海南地区5个气象站点逐日冻土观测资料和地温、气温资料,采用现代气候诊断分析方法,对海南地区冻土特征及其变化进行了分析。结果表明,近57a来冻土初日以每4.2d/10a的速率显著推迟,冻土终日以每3.8d/10a的速率显著提前,冻土期以8.0d/10 a的速率显著减少。20世纪80、90年代冻土初、终日发生了突变。从周期变化看,未来冻土初日处于推迟趋势,终日呈提前趋势。冻土初、终日与地、气温具有极显著相关性,地、气温每升高1℃,冻土初日分别推迟约8.1d、9.6d,冻土终日分别提早约8.8d、8.0d。海拔越高,冻土初日越早,终日越迟。

In this reseasrch,using daily frozen soil data and soil and air temperature data of five meteorological stations in Hainan Region during 1961-2017,the characteristics and variation of frozen soil were analyzed with modern climate diagnosis analysis method.The results show,frozen soil first date significantly delayed by 4.2 d/10 a rate,frozen soil last date significantly advanced by 3.8 d/10 a rate,the frozen soil period significantly decreased by 8.0 d/10 a rate in recent 57 years.The frozen soil first and last date had a mutation in 1980 s and 1990 s.According to the time series variation,Frozen soil first date is in delaying trend,but frozen soil last date is in early trend in the future.Extremely significant correlations between frozen soil first or last date and soil or air temperature were found,with frozen soil first data about 8.1 d and 9.6 d later,frozensoil last data about 8.8 d and 8.0 d earlier for every one degree increasing of soil and air temperature.For increasing of altitude,frozen soil first date was earlier,but frozen soil last date was later.