STUDY ON THE SPATIAL-TEMPORAL EVOLUTION OF SUBSIDENCE IN THE BEIBU GULF REGION BY TIME-SERIES INSAR

Abstract. In this paper, based on the 24 scenes Sentinel-1A images covering the Beibu Gulf region from 2018 to 2020, we used the PSInSAR technique to obtain the surface subsidence information in the study area and analyzed the surface subsidence spatial-temporal characteristics. The results showed that (1) The subsidence rate of most subsidence areas in Beibu Gulf is from −10.0 mm/year to −1.1 mm/year. And most of the subsidence areas are located in the coastal areas in the south of the study area. The distribution was obvious, and the maximum subsidence rate can reach −17.2 mm/a. However, the subsidence areas of villages and towns located in Qinzhou in the north and inland of the study area are relatively stable. (2) Subsidence was mainly concentrated in Yinhai District, Haicheng District, Tieshan Port District and Fangcheng District of Fangchenggang in Beihai City. The annual average Subsidence range from −10.0 mm/year to −1.1 mm/year. Among them, the Tieshan Port area and Fangcheng District had obvious subsidence trends, with the maximum cumulative subsidence reaching −35.9 mm. (3) The spatial-temporal characteristics of wide-area surface subsidence and the relationship between surface subsidence and influencing factors in the Beibu Gulf region were determined.