Surface Deformation of the Shanghai Coastal Area Revealed by a Multi-Satellite Dinsar Investigation

In this work, we investigate the evolution of ground deformation in the Shanghai coastal region, China, over the last decade. We performed a Small BAseline subset DInSAR analysis based on the exploitation of three independent SAR datasets acquired by the ASAR/ENVISAT (ENV), COSMO-SkyMed (CSK), and Sentinel-1A (SlA) sensors, spanning the time frame between 2007 and 2017. More precisely, we used a time-dependent geotechnical centrifuge model of the subsidence signals to combine the available time-gapped CSK and ENV datasets, and hence we produced a long-term CSK, ENV, and SlA displacement time-series. The maximum subsidence rate calculated by the combined long-term ENV+CSK+S1A deformation time-series is about 30 mm/year. The achieved results are beneficial for future studies assessing the environmental risk (e.g., due to flooding) of the population living in the coastal area of Shanghai.