Investigation and evaluation of the amount of railway line subsidence (Case study: Hamedan-Sanandaj axis)
Articles in Press, Accepted Manuscript, Available Online from 20 February 2026
Somayeh Abdi, Mustafa Khabazi, Behnam Moghani Rahimi
Abstract Introduction: The phenomenon of land subsidence has caused many problems and dilemmas in agricultural lands, roads, power and energy transmission lines for various reasons, including excessive extraction of groundwater resources and climate change. In the last decade, subsidence has been occurring as a geomorphic hazard in a large part of the plains of Iran, including the Ardabil Plain. The increasing human need for water resources in recent years has led to an increase in the exploitation of surface and groundwater resources. One of the hazards facing the plains of the country is the risk of subsidence.
Methods and Material: In this study, the annual land subsidence rate in Hamedan-Sanandaj province (Dehgolan-Qorveh and Hamedan-Bahar railway lines) has been investigated using data from the Sentinel 1 satellite and the combined aperture radar interferometry (InSAR) technique. To ensure the accuracy of the results obtained from processing satellite images, hydrological information including the water level of the region's piezometers has been used.
Results and Discussion: Based on the results of interferometric image processing, we are witnessing subsidence in the study area. The observed subsidence range from InSAR processing shows that the highest subsidence has occurred in areas with a high density of wells and thick clay layers. Finally, the results of radar interferometry show the subsidence rate in the Dehgolan-Qorveh area as 0.17, 1, and 1.5 mm per year, respectively. Next, using the GIS spatial information system, the risks of subsidence in the area were analyzed. The results show that important and strategic structures are at risk of subsidence.