基于合成分析的延吉市季节冻土对气候变化响应

Response of Seasonal Permafrost to Negative Accumulated Temperature in Yanji City based on Synthetic Analysis

利用1965-2018年延吉站的气温、降水、地表温度、冻土冻结日数等数据,采用合成分析,结合MannKendall检验、回归分析等数据统计方法,研究了吉林省延吉市54年来的负积温以及冻土冻结日数年际变化特征、对负积温与冻土冻结日数之间的关系进行了量化,并对突变后负积温降低但冻结日数依旧减少的原因进行了研究。Mann-Kendall检验表明突变发生于1992年,因此将整个时间序列划分为1965-1992和1993-2018两部分进行了合成分析,结果表明:突变发生前年负积温增温速率快,但冻土冻结日数减少速率慢;突变发生后年负积温增温速率慢,但冻土冻结日数减少速率快。冬季降水会呈现出保温作用,从而减少冻结日数。结果可以为农业生产制度及技术的改进提供科学的数据支撑。

Based on the data of air temperature,precipitation,surface temperature and days of frozen soil at Yanji Station from 1965 to 2018,combined with statistical methods such as Mann-Kendall test and regression analysis,synthetic analysis was adopted.This paper studies the interannual variation characteristics of negative accumulated temperature and frozen days of frozen soil in Yanji City,Jilin Province in the past 54 years,quantifies the relationship between negative accumulated temperature and frozen days of frozen soil,and studies the reasons why the negative accumulated temperature decreases but the frozen days still decrease after the mutation.The Mann-Kendall test showed that the mutation occurred in 1992,so the whole time series was divided into two parts:1965—1992 and 1993—2018.The results showed that the rate of increase of negative accumulated temperature in the year before the mutation occurred was fast,but the rate of decrease of frozen days was slow.After the mutation occurred,the annual negative accumulated temperature increased slowly,but the freezing days of frozen soil decreased rapidly.Precipita⁃tion in winter tends to have an insulating effect,thereby reducing the number of freezing days.The results can provide scientific data support for the improvement of agricultural production system and technology.