Land Subsidence and Subsurface Processes Monitoring System

The depletion of underground water resources has caused land subsidence across vast areas of the country. A recent article published in the scientific journal Science Advances highlights the adverse impact of subsidence in 265 cities out of 429 counties nationwide. This research utilized satellite imagery from 2014 onward for assessments.Findings indicate that 1.7 billion cubic meters of groundwater are extracted annually from confined and semi-confined aquifers. According to the study, nearly all provinces of Iran are affected by land subsidence. In some regions, the subsidence rate exceeds 12 centimeters per year. The research also reveals that about 14 million people—over one-fifth of the country’s population—live in areas experiencing severe subsidence.

Land subsidence has also placed Iran’s infrastructure at serious risk. According to the study’s findings, a significant portion of oil and gas pipelines, gas pressure reduction stations, water reservoirs, power substations, power plants, high-rise buildings, historical monuments, major urban and intercity bridges, hospitals, malls and large shopping centers, commercial and residential complexes, automaker parking facilities, factories, industrial and commercial warehouses, key administrative and security buildings, military sites, and other critical national infrastructure are located in subsidence-affected areas.The research further indicates that 8 out of 61 major and medium-sized airports in Iran are situated in regions affected by land subsidence. Among them is Imam Khomeini International Airport, which handles more than 8 million passengers annually. Other international airports in Isfahan, Urmia, Kerman, Gorgan, and Shahr-e Kord are also located in critical zones. Out of Iran’s 310 railway stations, 54 are in subsidence-prone areas, as well as 25 of the country’s 215 metro stations.

Land subsidence occurs at both regional and local scales. At the regional scale, subsidence is generally uniform and usually does not have a direct impact on structures, buildings, facilities, or infrastructure. Local subsidence, however, manifests as anomalies or sinkholes beneath foundations or subsurface areas and can cause direct damage and irreparable losses. This type of subsidence can be mitigated through measures such as concrete injection or various ground improvement techniques. Timely awareness of subsurface changes allows for identifying the optimal time to implement preventive actions.

Geopersian Seismography Co., with over a quarter-century of experience in monitoring equipment production, has designed and developed a predictive sinkhole monitoring system resulting from land subsidence. This system is capable of generating daily 3D images of subsurface low-density areas and providing them to users via the internet, intranet, or mobile devices. If areas with low density (air cavities) or potential sinkholes approach the surface, necessary alerts are issued to initiate ground reinforcement measures.