The Subsidence Detection and Analysis Along Kunming Subway Network Based on SBAS-InSAR

Abstract

Kunming, as an important urban interchange point along the “One Belt And One Road”, is in the peak period of subway construction. However, due to the ground characteristics, in the process of subway construction and operation, it is easy to cause surface subsidence, which threatens people's lives and property safety. Therefore, it is of great practical significance to master the ground deformation along the subway lines timely and accurately. Taking the Kunming subway network as an example, in this paper, 69 Sentinel-1A SAR images of Kunming city from July 20, 2018, to November 18,202,0 were processed by SBAS-InSAR technology, and then the surface subsidence information was extracted. On this basis, the spatial and temporal distribution characteristics of the surface subsidence of the five key subsidence areas and the 500m buffer zone along the subway are analyzed. The research results showed that from July 2018 to December 2020, the overall surface subsidence characteristics of Kunming were more obvious, and the subsidence rate is −123.98~31.52mm/a. The key subsidence areas are mainly distributed along the subway lines. The sedimentation value of the six subways was within the safe range except for settlement area 1 of Line 2 and settlement areas 3 and 4 of Line 4. This work demonstrates that the SBAS-InSAR technology based on Sentinel-1A SAR images has great potential in subway surface subsidence monitoring, which can provide a reference for government departments to carry out surface subsidence monitoring and disaster warning along the subway in the future.