And according to the Associated Press, they threaten people’s homes and the local infrastructure.
The ground is cracking open, according to the AP, thanks to a water crisis that has deepened as Tehran’s population has ballooned.
The region is in the midst of a three-decade-long drought and ongoing desertification.
According to a 2018 report from Circle of Blue, a nonprofit focused on water issues, that problem has been compounded as the city’s population has grown to close to 8.5 million.
Water pumped from underground aquifers has gotten saltier every year as the city has increasingly relied on these underground water sources as opposed to rainwater.
[10 Driest Places on Earth] As a result, land in the area is physically slumping in on itself.
A February study published in the journal Remote Sensing of Environment arrived at a similar number: 9.8 inches (25 cm), based on satellite measurements.
All that subsidence has cracked buildings and water pipes, opened holes in the drying earth, and caused miles-long fissures.
The problem is partly a result of international sanctions applied to the country since its revolution, the AP reported.
Iran has sought to produce enough food locally to feed all of its people in times of crisis, and this has over-stressed the water supply.