MONITORING THE GROUND SUBSIDENCE OVER YAN'AN HIGH-FILLED REGION BY USING TIME SERIES INSAR TECHNIQUE

In August 2018,the land creation project over Yan'an loess hilly-gully region has completed its geotechnical engineering. A total of 21.3 km² of new land is created for urban construction. In order to monitor the ground subsidence due to land creation, 191 sentinel-1A images spanning from October 2014 to July 2019 are processed by small baseline subset InSAR(SBAS-InSAR)technique. The results showed that the subsidence area is mainly concentrated in the land filling area, where the maximum deformation rate reaches 10 cm·y^-1. Based on the analysis and field investigation, the severe subsidence over the study area is caused by the consolidation of filling soil, and the filling thickness is the main factor controlling the subsidence rate. Our result demonstrates the reliability of SBAS-InSAR technique in ground subsidence monitoring over soil-filling region, and the obtained deformation results can provide sound management for local government.