Temporal InSAR Monitoring Of Frozen Soil Deformation And Analysis

With the gradual warming of global climate,the permafrost in the Qinghai-Tibet Plateau has a tendency of degeneration,such as increasing the thickness of active layer and shrinking the area,which will profoundly affect the ecological environment,water temperature environment,engineering construction,people's lives,economic construction and so on.In particular,the permafrost heave and thaw settlement of soil in frozen soil area is an important factor restricting the economic development of cold regions in China.So permafrost research has important practical significance for engineering construction,ecosystem,crop growth and so on.The research work and contributions of this paper mainly include:(1)Data preparation includes using band combination of Landsat 8 and GF-1 data to obtain surface classification through unsupervised classification;using Landsat 8 data to retrieve land surface temperature data,and using threshold method to remove clouds area from the temperature data;using DEM of National Aeronautics and Space Administration participates in the calculation of surface deformation in the study area,and obtains the information of slope degree and slope direction through relevant calculation.Based on the empirical data model of previous studies,the distribution of permafrost in the study area is calculated based on latitude.(2)Using the small baseline subset technique to calculate the Sentinel-1 data,the multi-temporal surface deformation information of the study area is obtained,and the triangular function model is used to describe the overall surface deformation of the study area.The results show that the permafrost heave and thaw subsidence of the frozen soil in the study area are periodic and linear.Its periodicity reflects the properties of frost heave and thaw settlement of frozen soil in the study area;moreover,there is a trend of subsidence in the study area as a whole.(3)This paper combines the surface classification results of this paper,the existing external classification results maps and DEM to analyze the deformation changes of frozen soil in the region,including 1:500,000 national geological maps,national surface coverage maps(Level 12),and national surface vegetation coverage maps(Level 9).The analysis shows that the strata with long time are relatively active;the subsidence or hot melt collapse of surface types at higher altitudes and with more moisture is more obvious,and has little correlation with temperature,on the contrary,it has relatively high correlation with temperature;the subsidence or hot melt collapse of areas with less vegetation is obvious,and also has little correlation with temperature,and the areas with more vegetation have obvious correlation with temperature.Negative correlation,the cumulative subsidence is not obvious.Deformation analysis of the north and south slopes of the mountain is carried out,and the typical mountain areas are selected for in-depth analysis.It is found that there is a negative correlation between the deformation of the back of the sun and the temperature of the mountain.