Land Subsidence Monitoring in Greater Vancouver Through Synergy of InSAR and Polarimetric Analysis

Abstract

Up-to-date spatial information on ground movements and land use is useful for emergency management of coastal regions. Time series InSAR techniques have proven to be effective tools for providing the former; however, InSAR results alone cannot be used to characterize the relationship between movements and land use. The focus of this study is to evaluate the potential to use high resolution radar satellite imagery for monitoring urban land subsidence associated with the construction of new building in Canadian coastal cities. To do this, we propose to integrate InSAR and polarimetric SAR information for deformation analysis. The methodology included multidimensional small baseline subset (MSBAS) InSAR analysis, polarimetric SAR change detection, and integration of the coherence, deformation, and polarimetric information for identifying the urban surface movements related to new buildings. The study was conducted in the Vancouver region, BC using RADARSAT-2 satellite data of ultra-fine mode and fine-quad mode acquired during 2010-2016. Results demonstrated that the integration of polarimetric and InSAR data permitted identification of ground movement, and the association of these movements to the new constructions in the urban environment. Several locations have been experiencing subsidence at a rate of up to 10 cm/year, and horizontal motion of 5 cm/year.