Application Of D-InSAR Technology In Land Subsidence Investigation

At present,land subsidence has occurred in more than 90 cities in China.The economic loss caused by land subsidence in China has exceeded 600 billion yuan.Land subsidence disaster has seriously hindered the sustainable development of cities.Compared with conventional GPS or leveling surveys,D-InSAR technology has many advantages,such as wide monitoring range,all-weather,low cost and fast data processing.It is suitable for long-term surface subsidence monitoring and other disaster prediction.At present,D-InSAR technology has been able to achieve centimeter or even millimeter-level monitoring accuracy,fully meet the requirements of high-precision monitoring in urban and mining areas.In this paper,Yongjing County,Gansu Province,is taken as the research area,and D-InSAR is used as the technical means.Based on the basic principle,the main interferometric decoherence sources are analyzed,and the data selection and processing are optimized.Then,based on the advanced radar image processing tool SARscape under ENVI software,surface deformation information is obtained.The maximum settlement is 42 mm,most of which is 1-10 mm,and 11 leveling measurements are used.The maximum error is 16 mm,and most of the errors are about 10 mm.On the basis of acquiring the information of surface deformation and combining with the spatial analysis and statistical function of multi-data of GIS technology,qualitative and quantitative analysis is carried out.It is found that the total area of settlement in the study area reaches 38.328 km~2,accounting for 2.05%of the area of the study area,which will threaten the safety of life and property of nearly 40,000 residents.At the same time,the settlement center in the study area has been more accurately positioned,and the settlement scale and settlement trend have been determined.Potential also has a more intuitive understanding.Finally,field investigation and field verification are carried out according to settlement characteristics.The results of the survey are in good agreement with the results of this study,which proves that the results of this study are successful and effective.It has great reference value for the control of land subsidence disasters in Yongjing County,Gansu Province,and provides data support for the sustainable development of Yongjing County.