The Spatial And Temporal Variation Of Seasonal Frozen Soil Thickness In Heilongjiang Province And Its Response To Temperature And Land Use Change

This study used the Mann–Kendall test,the smoothing T-test,and empirical orthogonal function analysis method to analyze the temporal and spatial variation characteristics of permafrost thickness in Heilongjiang Province,with daily permafrost monitoring and temperature data obtained from 32 meteorological stations in the past 50 years.The results are as follows:(1)The permafrost thickness in Heilongjiang province is obviously decreasing,and the annual decline rate is-5.3 cm/10 a.(2)In 1970 s,the average thickness of frozen soil reached the maximum,and then decreased after 1980 s.(3)Compared to 1961,2012 in Heilongjiang province in spring,summer,autumn and winter,the average thickness of frozen soil were reduced by 40 cm,12 cm,10 cm,27 cm,the coefficient of variation were 11.6%,7.8%,10.9%,8.9%,spring frozen thickness variation is relatively not stable.(4)The thickness of frozen soil mutation phenomenon obviously,possible mutations in 1997 and 2001,that is to say,at the end of 1990 s,Heilongjiang Province,permafrost thickness changes,before the thickness of frozen soil after 2001 was obviously less than that in 2001,2001 is possible.The time for the thickness of frozen soil.(5)The overall distribution of permafrost in Heilongjiang shows a thick north and South thin pattern,Compared with the same latitudes,the thickness of the permafrost in the middle of Heilongjiang province is lower than that of the other regions in the same latitude,and the Hulin in the southeast is also a low value area.The highest thickness of the permafrost is located in the Greater Khingan Range area and the second in the small Xingan ridge.(6)The spatial distribution of the decreasing tendency of permafrost thickness tends to gradually thinner from north to south,and the thickness of permafrost in the middle area is lower than that in latitude.In the middle of the thickness of frozen soil and the West and Southeast opposite changes,which Yichun City,Tieli city and Mohe County County as permafrost area or fragile areas sensitive to changes.(7)The thickness of frozen soil and temperatures have a significant negative correlation,the correlation coefficient is-0.611.(8)The decline rate of permafrost thickness in the frozen soil observation station of land use type is relatively small compared with other land use types.This paper focuses on the analysis of the distribution and change characteristics of Heilongjiang Province,the thickness of frozen soil in the time and space variation,and the influence of temperature and land use types on the frozen soil thickness,and permafrost related transportation,development area of Heilongjiang Province agricultural production activities,establish a comfortable residential and urban scientific on the basis of Longjiang,supporting rapid socioeconomic development needs.