A map of land subsidence of the capital Tehran
Iran International has obtained documents revealing that Iranian officials are aware of dangerous land subsidence but are unwilling to share it with the public.
On Saturday, Iran International television released its exclusive report about the issue, leaking a confidential letter from the country’s National Cartographic Center addressed to former agriculture minister Javad Sadatinejad, who was removed by President Ebrahim Raisi mid-April without announcing any concrete reasons.
In the letter, Ali Javidaneh an official at the center says that about 550 square kilometers of land in and around the capital Tehran (about the size of the UK city of Manchester or the US city of El Paso, Texas)is sinking an average of over 13 centimeters (about 5.12 inch) per year.
He said that parts of critical infrastructures in the area are affected by subsidence, adding that parts of the highway and the area’s power transmission lines as well as part of the railway pass through the affected areas.
According to another document with details about land subsidence across the country, 380 cities and towns and 9,200 villages are at risk of land subsidence and in some cases the entire area of the cities are located in the subsidence zones.
The confidential letter obtained by Iran International
According to the data in the report,which was not made available to the public either, almost all the provinces of the country are affected by the issue. Bahreman, a city in the central province of Kerman, is on top of the list with 42 centimeters (about 1.38 ft) subsidence per year.
A day after the Iran International’s report, the National Cartographic Center unveiled a map of the country’s land subsidence during a geomatics event in Tehran.
Confirming our report, MasomehAmighpey, an official of the center, was cited by state media as saying that "In the assessments, we identified 245 subsidence prone areas, 30% of which have a high rate of subsidence." She added that 14 metropolises of the country are affected by land subsidence, and according to the statistics of the Energy Ministry, 70% of the country's plains are in crisis due to mismanagement.
Land subsidence is not limited to big cities with big construction projects. In many areas in Iran cracks and huge hollows that resemble meteor craters have appeared in the ground in recent years.
Experts say that over-extraction of ground water has led for cavities being formed underground which in turn lead to subsidence.
According to a report in March, the current level of land subsidence in Iran is “critical", with experts claiming it puts the lives of more than 39 million people at risk, about half of the country’s population.
Several factors have caused the situation to reach breaking point, including dam construction, climate change, inefficient water consumption by agriculture and industries, and the use of underground aquifers as sources for illegal agricultural water extraction wells.
Ali Beitollahi, heading the disaster task force on the issue at the Road, Housing and Urban Development Research Center of Iran, said the approximate area of subsidence zones in the country is now 18.5 million hectares, almost 11% of Iran's total area.
However, international reports claim the danger is even worse, nearing a humanitarian crisis. Science journal claims that more than 98% of Iran's 1.648 million km of land faces land subsidence.
Internationally, a rate of subsidence greater than 4mm (about 0.16 in) per year is considered a crisis and yet Iran's land is sinking at an astonishing rate of 6cm (about 2.36 in) per year in average as a result of 25 years of water level decline in the plains.
Ground subsidence in urban areas has resulted in power outages, bursting of gas pipes, deformation of rails, emergence of sinkholes, tilting of buildings, the appearance of cracks and ditches in roads and even loss of human life.Continued water level declines will reduce the ground's water permeability and turn fertile plains into barren deserts.