APPLICATION OF INTERFEROMETRIC SYNTHETIC APERTURE RADAR DATA IN ASSESSING LAND SUBSIDENCE RESULTING FROM HUMAN FACTORS IN NINH BINH PROVINCE, VIETNAM

The method of Satellite Interferometric Synthetic Aperture Radar, based on analyzing the phase difference of radar complex images recorded from two different positions simultaneously observing a terrain area where the signals have the same amplitude, frequency, and wavelength but different phases, the deformation of the terrain surface in Ninh Binh province is analyzed and calculated. The preliminary results include the construction of a deformation map of the ground surface in the Ninh Binh province for the period 2020 - 2021, consisting of 78,077 points. The map shows areas that have been uplifted with values of 3 - 5 mm/year and >5 mm/year, particularly highlighting areas with significant subsidence velocities of <-10 mm/year (Kim Son and Yen Khanh districts), some areas with subsidence velocities ranging from -5 to -10 mm/year (Yen Nhan commune, Yen Mo district, Nam Binh ward, Ninh Phong district in Ninh Binh city), and subsidence values of 0 to -5 mm/year in the communes bordering between Nho Quan and Gia Vien districts. These results provide a basis for identifying the causes of terrain surface changes and proposing solutions to prevent and mitigate damages in Ninh Binh province; In-depth studies will continue.