Study On The Spatiotemporal Variation Characteristics Of Seasonal Frozen Soil In Heilongjiang Province And Its Response To Climate Chang

Frozen soil is a temperature-sensitive and volatile geological body that interacts with climate.Changes in temperature have an important impact on the frozen soil environment.On the one hand,climate change will affect the thickness and distribution of frozen soil.On the other hand,the melting of frozen soil may also cause changes in hydrology and engineering foundation and will also have a great impact on the ecological environment built on it.Once the deterioration of frozen soil accelerates,it may lead to landslides and soil subsidence,which will adversely affect people’s daily life,engineering construction and agricultural production.Under the background of global warming,we using the frozen soil observation data of 18 observation stations in Heilongjiang Province from 1972 to 2016 and the daily temperature observation data of 35 national meteorological observation stations from 1972 to2020,based on the linear regression method,Mann-Kendall mutation test,Kriging interpolation,various indicators of seasonal frozen soil in Heilongjiang Province(including average freezing depth,maximum freezing depth,first and last days of freezing,etc.)and temperature indicators(including average temperature,maximum temperature,annual the development trend of negative accumulated temperature,etc.)were studied and analyzed,and the results show that:1.Average freezing depth and maximum freezing depth showed a decreasing trend.The decreasing rate of the average freezing depth is 4.8cm/10 a,and the decreasing rate of the maximum freezing depth is 10.1cm/10 a.The first day of freezing shows a delayed trend,and the delay rate is 1.4 d/10 a,and the last day of freezing shows a forward trend,the lead rate is5.2 d/10 a.2.The annual average temperature shows an upward trend on the whole,with a rising rate of 0.3°C/10 a,and the minimum temperature rise rate is significantly higher than that of the average temperature,which is 0.4°C/10 a.3.The correlations between the average freezing depth and the maximum freezing depth with the average temperature are-0.59 and-0.55,respectively.The specific performance is that every 1°C increase in the annual average temperature will cause the average freezing depth to decrease by 7.3 cm;the maximum freezing depth will be reduced by 14.93 cm.