On Sunday, August 31, the state-run Mehr News Agency reported, citing Eskandar Sayedaei, head of Iran’s National Cartographic Center, that a “classified atlas of land subsidence in Iran” has been prepared.
In this document, which is said to have been presented to responsible institutions “for warning and policymaking,” statistics and information have been released that some Tehran city officials have described as “horrifying.”
According to the report, the head of the National Cartographic Center of the Iranian regime announced that the highest rate of subsidence is “in the Bahraman plain in Kerman province with 31 centimeters, and also in one of the areas of Tehran with about 30 centimeters.”
The head of the National Cartographic Center further noted that this level of land subsidence in Iran occurs while, according to global standards, subsidence of more than about three centimeters is considered a warning.
Sayedaei, stating that the rate of land subsidence in Iran is several times higher than the global average, added that this issue has “turned into a serious threat to the country’s environmental and construction security.”
Without giving further details about the reason for the secrecy of the land subsidence report in Iran, he said: “We provide this information in the form of classified reports, correspondences, and files to the relevant institutions that inquire from us, with clear percentages, quantities, and qualities.”
The head of the National Cartographic Center stated that the main reason for land subsidence in Iran at this scale is “excessive extraction of groundwater” and added: “If this continues, infrastructure, buildings, power transmission lines, and even historical monuments will be at risk.”
He added: “Subsidence has no immediate solution, and the only sustainable remedy is to stop excessive water extraction.”
The National Cartographic Center had previously warned that in addition to Tehran, parts of other major cities, including Isfahan and Tabriz, are also at risk of subsidence.
The situation of land subsidence has also been reported as severe in other provinces, including Alborz, Fars, Kerman, Hamedan, Semnan, Qazvin, Razavi Khorasan, North Khorasan, and Yazd.
The statistics of land subsidence in Tehran are “horrifying”
Continuing the remarks about land subsidence in Tehran and other parts of the country, Mohammad Aghamiri, head of the Urban Development Committee of Tehran’s City Council, told reporters on August 28: “The statistics of subsidence in Tehran are classified and I cannot disclose them. Just know that these figures are horrifying.”
Land Subsidence Warnings in Tehran and the Critical Situation of 70% of Iran’s Plains
According to Aghamiri, in Tehran’s District 18, which sits on one of the city’s main aquifers, “excessive extraction of water from the aquifer has been so intense that the area is now experiencing 20 centimeters of subsidence.”
In 2022, the former head of Tehran Municipality’s Environmental Department also declared Tehran the “world record-holder of land subsidence” and described this phenomenon as a “silent earthquake or the cancer of the earth.”
Previous studies by Iran’s Geological Survey had shown that some areas around Tehran experience an annual subsidence of 25 centimeters, although this subsidence is not uniform across all parts of Tehran’s outskirts.
Some experts, referring to satellite images from the research institute “IntelLab” on land subsidence around Tehran, had previously described this phenomenon as a “silent time bomb” and a “threat to the 13 million people living in these areas.”
According to experts, the pressure caused by groundwater extraction, combined with the capacity of land in aquifers to subside, creates an interaction that makes the rate of land subsidence vary from year to year.
Based on this, land subsidence mainly occurs in agricultural lands on the outskirts of cities and villages that are composed of sediments or fine-grained soils.
Previous studies by the Geological Survey had shown that subsidence exists in all plains of Iran that “contain extractable fresh water,” and that “there is no plain left in Iran that has been spared from subsidence.”
Experts believe that land subsidence “means the death of aquifers,” and when aquifer particles are compressed due to land subsidence, they can no longer return to their original state. Therefore, subsidence is considered an irreversible hazard.
