Performance Assessment of InSAR-Based Vertical Displacement Monitoring of Sluices in Coastal Soft Soil Area

Sluices are main flood control infrastructures in coastal areas, where soft rock and soft soil are widely distributed. In soft soil areas, the vertical displacement of sluice is common, which is the main factor affecting the sluice safety. So, it is very important for sluice safety control according to the prototypical observations on deformation. Considering some drawbacks of leveling, such as it can only provide a limited number of points and requires time-consuming field work, this paper evaluates the performance of Interferometric Synthetic Aperture Radar (InSAR)-based method in monitoring long-term vertical displacement deformations of sluices. Taking 12 sluices in Northern Jiangsu, China as an example, 129 Sentinel-1 C-band VV-polarizatio ascending SAR images that span the period from April 2015 to January 2020 were used to monitor their vertical displacement deformations. The leveling results are made to verify the accuracy and reliability of Permanent Scatterer InSAR (PSInSAR) method. The validation indicates good agreement between PSInSAR results and leveling results. Considering the higher accuracy of leveling, PSInSAR method is more suitable as an auxiliary technology besides leveling method to focus on the early warning of sluice deformation risk events.