Monitoring Land Subsidence Patterns in Southwestern Tehran Using Radar Interferometry Time Series and Global Positioning System Observations

Rezaeezadeh, Amin; Tayfehrostami, Arash; Amiri, Meysam

doi:10.22059/ije.2025.397729.1875

Monitoring Land Subsidence Patterns in Southwestern Tehran Using Radar Interferometry Time Series and Global Positioning System Observations

Articles in Press

Document Type : Research Article

Authors

¹ Department of Construction Engineering, École de technologie supérieure ÉTS, 1100 Notre-Dame St W, Montreal, Quebec, H3C 1K3, Canada

² Faculty of Geodesy and Geomatics Engineering, K. N. Toosi University of Technology, Tehran, Iran.

³ Ph.D. in Geophysics Department of Earth Sciences Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran

10.22059/ije.2025.397729.1875

Abstract

Excessive groundwater extraction coupled with prolonged drought has caused severe land subsidence in Iran's plains, particularly in southwestern Tehran where alarming sinking rates have been observed over the past two decades. This study employs Interferometric Synthetic Aperture Radar (InSAR) with the Small Baseline Subset (SBAS) technique to analyze land deformation patterns from 2014 to 2017, providing critical updates to pre-2010 studies. Our results reveal maximum subsidence rates of 174 mm/year along the satellite's line-of-sight and 227 mm/year vertically, confirming the ongoing severity of the crisis. Interestingly, the time-series analysis identified periodic uplift events strongly correlated with rainfall exceeding 20 mm, with six distinct episodes showing over 50 mm of uplift following heavy precipitation. These findings demonstrate the complex interplay between anthropogenic groundwater depletion and natural precipitation variability in controlling land surface movements. While temporary uplifts provide short-term relief, they cannot compensate for the long-term subsidence caused by aquifer overexploitation. The study highlights the necessity for continuous InSAR monitoring combined with hydrological data to better understand deformation mechanisms and inform sustainable water management strategies. These insights are particularly valuable for urban planning and infrastructure protection in Tehran's rapidly subsiding southwestern areas, where the risk of irreversible damage continues to grow.

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