Land Uplift Monitoring and Analysis in Yan'an New District Based on SBAS-InSAR Technology

  Objectives  The mountain excavation and city construction in Yan'an New District is one of the largest land-creation projects in the Loess Plateau. Large-scale mountain excavation has induced extensive land uplift in the region. At the same time, the excavation area is the main site for the urbanization of the new district, and the land uplift has seriously affected the sustainable development of urbanization in the new district.

  Methods  In this study, the small baseline subset synthetic aperture radar interferometry (SBAS-InSAR) technology was utilized to process the ascending Sentinel-1A data stacks covering the new district from May 2016 to October 2019 to retrieve long-term ground deformation information after construction. The spatial pattern of ground uplift and its time deformation evolution characteristics was revealed, and the causes of land uplift were further quantitatively analyzed in detail.

  Results  The results show that significant land uplift of the new district after construction is mainly distributed in the excavation area that has the greatest impact on human engineering activities, with a maximum uplift rate of 24.8 mm/a. The ground lifting deformation develops rapidly in the early post-construction period, and it tends to slow down and stabilize over time.

  Conclusions  The unloading rebound deformation caused by the rapid mountain excavation is the main internal factor causing land uplifting, and the distribution and magnitude of the land uplifting are the result of the combined effects of external factors such as excavation engineering, excavation thickness, and building load.