Correlation analysis of freezing and thawing index and factors affecting frozen soil degradation in typical seasonally frozen ground in northeast China during 1960-2023
Correlation analysis of freezing and thawing index and factors affecting frozen soil degradation in typical seasonally frozen ground in northeast China during 1960-2023
[Objective]The freezing and thawing cycling process of seasonally frozen ground significantly affects the water cycle and the evolution of frozen soil layer in the watershed.The freeze-thaw cycle of seasonally frozen ground significantly affects the water cycle and the evolution of the seasonal frozen soil layer in the basin.The evolution of the freeze-thaw process is clarified to provide theoretical support for safeguarding the ecology of seasonally frozen ground and the construction and operation management of water conservancy and hydropower projects.[Methods]Based on the data from 10 meteorological stations and frozen soil ob-servatories in the typical seasonally frozen ground in northeastern China,analysed the spatial and temporal distribution character-istics of the freezing and thawing index from 1960 to 2020,and calculated the maximum freezing depth,the date of the start of freezing,the date of the complete thawing,the period of freezing and thawing,the rate of frozen soil degradation,and combined them with the climatic(annual average temperature,freezing temperature change rate,freezing index,thawing index)and geo-graphic parameters(latitude,longitude,elevation),to assess the freeze-thaw status of frozen soil and the effects of maximum depth of frozen and frozen soil degradation rate on the typical seasonally frozen ground with freeze-thaw status from 1960 to 2023.[Results]The result show that the freezing index decreases at a rate of 55.10℃ d/10a,moreover,the thawing index increases at a rate of 60.80℃ d/10 a in the typical seasonally frozen ground in northeastern China.The maximum freezing depth ranges from 68.00 to 260.00 cm during the 60 years,and the rate of frozen-soil degradation ranges from 0.07 to 1.45 cm/a.the rate of delay in the date of the start of freezing is 1.15 d/10 a,the date of complete thawing is significantly advanced at a rate of 4.71 d/10 a,and the period of freezing and thawing is shortened at a rate of 5.60 d/10 a.[Conclusion]The freezing index is correlated with latitude,while the thawing index is correlated with altitude.The maximum freezing depth in the typical seasonally frozen ground in the north-eastern part of China is mainly affected by the average annual temperature and latitude,frozen soil degradation is mainly affected by the rate of change of freezing temperature,and the freeze-thaw period is significantly affected by the average annual temperature.
关键词
冻融特征/时空演变/影响因素/贡献分解/季节性冻土区
Key words
freezing and thawing characteristics/spatial and temporal evolution/influence factors/contribution decomposition/seasonally frozen ground
万方数据