Correspondence of PSInSAR monitoring and Settle3 modelling at Cochin International Airport, SW India

The short-term deformation of Cochin International Airport Limited (CIAL), southwestern India, built on the massive floodplain of the Periyar River, is the topic of inquiry in this study. An unprecedented flood of August 2018 instigated a refined understanding of the ground deformation, if any, of the CIAL property. Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR), using Sentinel-1A images, was used for documenting the ground deformation, which generated 5563 Persistent Scatterer Interferometric (PSI) points. Though the velocity of PSI points swayed positively (maximum velocity of 23.61 mm/y) and negatively (minimum velocity of − 21.83 mm/y), the majority values were negative. Interpolation of velocity values showed the predominance of the negative field for all the components of CIAL infrastructure. Ground deformation was modelled using Settle3, based on standard penetration test (SPT) values of five boreholes in the study area. Comparison between the PSInSAR and Settle3 modelling of deformation shows correlation amongst the mean values of both the approaches. PSInSAR monitoring and Settle3 modelling results relate to the varying thickness and properties of soils both in situ and the landfilled material. Findings also highlight the need for geological and geotechnical site characterization before the construction, and remote monitoring of critical long-term assets, especially strategic ones such as airport.