关键词: DS-InSAR, 永久散射体, 北江大堤, Sentinel-1, 形变

Abstract: Deformation monitoring of embankments is of great significance for flood prevention safety and engineering maintenance.This study employed DS-InSAR technology to monitor the deformation of the Sanshui section of the Beijiang embankment in Guangdong province,based on 74 scenes of Sentinel-1A data from 2019 to 2023.By integrating persistent scatterers (PS)and distributed scatterers (DS)signals,the spatio-temporal distribution characteristics of embankment deformation were obtained.The results indicate that: ①The annual deformation rate in the study area ranged from -9 to 6mm/a,showing significant spatial heterogeneity,with three subsidence centers formed from north to south.The maximum subsidence rate reached -9mm/a at the turning point of the embankment in the Lubao Town section (region B),while the subsidence area in the Leping Town section (region C)extended to the 200m protection zone outside the embankment.②Cumulative deformation analysis revealed a notable acceleration in subsidence during 2022—2023,with the subsidence in 2023 alone accounting for 61.5%of the total over five years.The cumulative subsidence near the Lubao Sluice reached -39mm.③Time-series analysis of characteristic points showed significant subsidence in PS1 and PS2 in September 2023,while PS3 exhibited a stable subsidence trend.PS4 underwent alternating uplift and subsidence processes.This study validates the applicability of time-series InSAR technology in monitoring earthen embankments and provides scientific support for the safety maintenance of critical embankment projects in the Pearl River Delta.

Key words: DS-InSAR, persistent scatterer, Beijiang embankment, Sentinel-1, deformation