Research On The Influence Of Vegetation Change On The Temperature Of Permafrost In The Northern Part Of Daxinganling

The construction of the permafrost area in the northern part of the Daxinganling Mountains is accelerating,the vegetation coverage is constantly decreasing,and regional engineering geological disasters occur frequently.Therefore,studying the influence of vegetation changes on the temperature of permafrost is of great significance for disaster monitoring,frozen soil environment and safe operation of cold area projects.Based on Landsat and MODIS data,this paper analyzes the spatial and temporal changes of vegetation in the study area.The vegetation coverage area is decreasing from2000 to 2016,and there are differences in vegetation coverage in different seasons.Study the influencing factors of surface temperature and its spatial and temporal changes in the northern area of the Daxinganling Mountains,and analyze the correlation between surface temperature and air temperature,elevation,NDVI(Normalized Difference Vegetation Index)and surface types.Further analyze the quantitative relationship between the surface vegetation index(NDVI)and the Land Surface Temperature(LST)in the study area.According to the measured data,the dynamic characteristics of water and heat transfer in the active layer of permafrost are analyzed,and the effects of vegetation on the freezing and thawing process in the active layer,the changes of vegetation coverage,ground temperature and water change rate are studied.Systematically develop the law of annual temperature change curve of permafrost with depth,establish the maximum annual melting depth of the disturbance zone and natural ground and the corresponding prediction model of permafrost degradation rate,and explore the impact of vegetation changes on permafrost degradation.Finally,the law of vegetation change and the spatial and temporal change of the temperature of permafrost in the north of the Daxinganling Mountains is proposed.