Assessment of land subsidence phenomenon in Kolkata city, India using satellite-based D-InSAR technique

In this study, one of the latest space-based techniques for measuring sub-centimetric ground displacement, Differential Synthetic Aperture Radar Interferometry (D-InSAR) has been used to assess the potential land subsidence phenomenon of Kolkata city, India. The occurrence of a thick surface clay layer with an average thickness of similar to 40 in and above, raises a question on the land subsidence phenomenon in Kolkata city. At this juncture, the D-InSAR-based study will help to ascertain the actual land subsidence scenario of Kolkata city. We have identified an area in Kolkata city in and around Machhua Bazar, Calcutta University and Raja Bazar Science College, which had been undergoing subsidence during the period of observation, i.e. 199298 with an estimated rate of 5 to 6.5 mm/yr.