Deformation Time-series Analysis and Disaster Potentiality Inversion by Short Baseline Interferometry Measurement

Synthetic aperture radar interferometry (InSAR) measurement technology is a new remote sensing technology that can effectively monitor slight land deformation. Compared with traditional monitoring technology, InSAR technology has the advantages of wide coverage, all-weather and low cost, providing a technical means of high-resolution, high-precision and low-cost for hidden geological hazard identification and deformation monitoring along pipelines. For purpose of this paper, considering the complex terrains of research area, SBAS-InSAR technology was adopted for deformation information extraction. This technology performs better in identifying fast deformation by controlling temporal and perpendicular baseline thresholds, which is able to prevent temporal de-coherence caused by fast deformation. In this paper, we performed deformation time-series comprehensive processing and analysis on gas pipeline based on Sentinel-1 image data through short baseline data processing, obtained deformation results in terms of time series by calculating linear deformation rate and nonlinear deformation phase based on residual phase separation nonlinear deformation phase and atmospheric effect phase, and then conduct parameter calculation, linear deformation rate calibration, accumulative deformation quantity calculation, etc. Finally, we extracted pipeline deformation quantities from 2020 to 2022. The result showed that, the land deformation rate of the ascending track data during this period ranges from -43 mm/year to 25 mm/year, and that of the descending track data from -66 mm/year to 33 mm/year. The results show that the area along the gas pipeline is in stable condition on the whole, deformation mainly occurred along a section in the northwest of Haidian District, and a large quantity of deformation occurred since January of 2020 until December of 2021, with the maximum deformation quantity of -70mm, This result provided a reliable reference for safety monitoring and repair & maintenance of the gas pipeline.Further more, The possible causes of the deformations mainly include surface subsidence, groundwater mining and such factors. Precautionary measures need to be enhanced for the area at potential risk of surface subsidence, to get rid of the threat of sudden geological disasters and resulting losses particularly in extreme weather conditions. At the same time, terrains and geographical realities should be considered to further determine whether there exists any hidden geological hazard like unstable slope, surface subsidence or landslide and decide the potential risk the pipeline is faced in combination with actual conditions.