TEHRAN – According to Hossein Zafari, head of crisis management agency, approximately 254 regions and plains in the various states of the country are affected by land subsidence.
Kerman, Khorasan Razavi and Tehran states are most affected by the phenomenon, Isna quotes Zafari as saying.
Land subsidence varies between 2-18 centimeters in different parts of the country, he added.
The country’s land subsidence has been strengthened since the early 1970s due to urban population concentration, climate change, low rainfall, frequent droughts, and increased groundwater extraction.
Land subsidence occurs in two ways. In some areas, uniform settlements descend evenly without visible surface signs, while in others, asymmetric settlements cause visible damage to the ground. Zafari said that assessing and monitoring this phenomenon is an ongoing process.
Referring to the high-risk regions of Tehran, officials said the south, southwest, southeast and southern regions of Tehran are prone to subsidence risk.
Zafari emphasizes the fact that groundwater overdose is a major contributor to land subsidence, and said that part of the crisis management organization’s operational plans and measures focus on preventing excessive water consumption, while others focus on reforming laws and regulations and practices used to construct and maintain key structures and facilities in affected areas. However, the organization’s main mission is to monitor and follow up on the actions required by responsible institutions and agencies.
Wide-area land subsidence: national crisis
Iran’s water supply is heavily dependent on rainfall, snow melt and underground aquifers, but decades of overextraction have led to severe depletion of groundwater resources. While global water resources are being sluggished by climate change and population growth, farms and industries are increasingly turning into groundwater, meeting their needs.
Unfortunately, pumping up groundwater will drain the aquifer below, and the ground will sink as the building on the ground collapses. This phenomenon is called land subsidence. This article attempts to introduce phenomena and underlying causes primarily in Tehran.
With over 15 million residents, including a large floating mass, Tehran is currently on the cliff of a severe land subsidence crisis. Founded in 1953, Iran’s National Mapping Centre (NCC) proves its role as a leading leader in domestic map production and spatial information. According to Iran’s NCC, some areas are sinking at an incredible rate of 31cm a year, causing chaos to critical infrastructure and historic sites, causing a national crisis. There are several examples of historic sites like cracked houses, sloped mosques and ancient ruins of Persepolis. Even modern infrastructure such as Imam Khomeini International Airport has not escaped the negative effects of land subsidence.
According to another source, scientists at the GFZ German Geoscience Research Center in Potsdam used satellite data to determine the extent of subsidence. The team used a tool known as the Interferometric Synthetic Aperture Radar (INSAR). They revealed that the land around Imam Khomeini International Airport (IKIA) sinks at about 5 centimeters a year. Unfortunately, this was one of the more moderate areas of subsidence.
This crisis is different from earthquakes and severe weather events that report media and television on an international scale. Land subsidence occurs at a very slow pace and is invisible, but the effects cannot be ignored.
Other causes of this phenomenon are attributed to lack of rainfall, uneven distribution of water, high climate change and inadequate management of valuable water resources. Subsidence is also associated with mining. Demographic factors such as population explosions have also been cited. Just 50 years ago, Tehran had a population of just 2 million. The rapid expansion of urban population has made the water distribution challenge even more challenging.
The Amilkabil dam, passing through the Karaj River, has been reduced from 7% to 220.9 billion cubic meters, recently cited by a spokesman for the Iranian Water Resources Management Company, a spokesman for Iranian water resource management company Isa Bozolutzede. The concrete dam, 30 km northwest of the capital, was built in 1961 to supply water and electricity to Tehran.
Latian Dam is a Buttless Dam located within 25 km of Tehran, south of Labasan city. Built between 1963 and 1967, it is one of Tehran’s main sources of water and electricity. With a capacity of 95 million cubic meters, the dam has been in operation since 1967.
70% of Tehran’s water comes from five nearby dams, including Amilkavir and Latian. As of March 5th, the reservoirs were only 13%, according to state media reports.
Looking back at five years ago, Mehr News Agency in May 2019 reported that Amirkabir Dam was filled with 93%, an increase of 4% compared to the previous year. The significant improvement was attributed to exceptional water rapids that covered almost all states sixty years later.
Unfortunately, this year’s water shortage was also due to low precipitation, which the Department of Energy said was not at 93.8mm from early October to mid-March.
In this situation, reducing water use, minimizing waste, and recycling water are good first steps. Optimizing water usage can reduce water consumption and reduce excess extraction of groundwater.
Last year, President Masoud Pezeshkian called for the relocation of Iran’s political and economic centres away from Tehran, citing environmental and infrastructure challenges in the capital.
“We have no choice but to bring the country’s political and economic centre closer to the southern waters,” he said, adding that Tehran’s current development trends are unsustainable, especially given the urban water shortages.
“Whatever we do, we’re just wasting time. We have no choice but to move the country’s economic and political centre south and get closer to the ocean,” he said.
Air pollution has become part of this issue given Tehran’s large population and its economic center. The air quality of the capital contaminates water storage downstream in the form of mountain ice.
The underlying cause of this crisis comes from an overextraction of groundwater, rising from 10 cubic meters in 2020 to 17.5 in 2023.
Without immediate reforms in water management and infrastructure planning, the capital faces an escalation of risk to infrastructure, heritage and population.
Unsustainable global practices for managing water resources ultimately lead to restrictions and reduced supply. It makes today’s uninterrupted, endless supply of water look like a dream.
Today’s Earth Wars are in the land and energy resources, but future wars will inevitably fight for more important resources.