Power outages, gas pipe bursting, rails deformed, sinkholes, buildings tilting, roads cracking...
Tehran plains ground subsidence has been covered and studied in recent decades however this man-induced phenomenon is now catching Tehran city itself for the last years thus endangering a growing population of 13 million inhabitants and its critical infrastructures.
Excessive groundwater extraction has caused land subsidence at a rate of up to 25 centimeters per year in some areas.
In this brief study, Differential InSAR processing was used to identify and estimate land displacement by using Sentinel-1A SAR SLC imageries. Our dataset includes 14 pairs of images from January 2020 to May 2021 with a small temporal-perpendicular baseline and using the SBAS approach, processing was performed by the GAMMA Software via ASF DAAC .
The results were further converted to an estimated vertical ground displacement map with a maximum average subsidence rate of 40mm/year.
It is known that subsidence phenomenons are non-linear, this estimated average rate takes into account events that occurred with higher subsidence during the period of images acquisition as well as events with ground uplift.