InSAR-Based Monitoring of Ongoing Land Subsidence in Ahmedabad, India’s First Heritage City

Monitoring land subsidence in growing urban conglomerates is very crucial to mitigate its adverse socio-economic impacts. In this study, we characterize the ongoing land subsidence over parts of Ahmedabad, India’s first heritage city using SqueeSAR, an advanced InSAR time series processing algorithm for time period 2016-24. The analysis suggests sinking of land in parts of Bopal and Narolgram area at rate of 2-3 cm/year over areal extent of $16 \mathrm{~km}^{2}$. The nature of subsidence is further investigated using Temporal Independent Component Analysis (TICA). The results suggest sinusoidal signals superimposed over linearly decreasing trend as most dominant component the deformation. The subsidence areas are mainly located on southern margin of the Ahmedabad and are hotspots of ongoing infrastructure development.