The Analysis of Three-dimensional Surface Deformation in Heifangtai Platform Using Ps-insar Technology
Chenxing WANG#+, Tonglu LI
Chang'an University, China

The serious surface subsidence and deformation has occurred due to the long-term agricultural irrigation in the Heifangtai area, as a typical loess tableland, and has induced many loess landslides. However, limited by the observation methods, the research on the three-dimensional deformation characteristics of this area was limited. The surface deformation in the Heifangtai Platform was taken as the research object in this study. The principle of obtaining three-dimensional surface deformation based on PS-InSAR technology was introduced. Besides, based on the deformation data of sentinel-1A satellite in different orbits, the characteristics of three-dimensional surface deformation in the Heifangtai area from 2014 to 2017 were analyzed, and its development trend was predicted. The results show that the vertical deformation in the middle of the tableland is large, especially in the villages and nearby villages, and the average deformation rate is -20~-6 mm/y. Meanwhile, the hazardous area of landslide along the tableland has large vertical deformation. The deformation results of the 9 regions selected show that the east-west deformation in the whole tableland is large, and the average deformation rate is more than 20 mm/y, which is much higher than that in the north-south direction (e.g. -5~5 mm/y). Therefore, there are uneven settlements in the study area. Besides, the surface subsidence in the study area still maintains a slow and accelerated development stage in the short term. This study provides a reference and guidance for the study of the multi-dimensional deformation characteristics of the surface in the prone area of loess landslide induced by irrigation.