This city is a home to 15 million people. Taking population into count, Tehran is the biggest city of western Asia.
As per the data collected from satellite pictures between 2003 and 2017, there has been sinking of many villages of Tehran’s northwestern region, reported Nature, a leading journal.
In some areas, sinkholes are visible as a part of process known as subsidence. In one such case, a farmer fell into a 20 feet deep crack that opened suddenly while he was standing, Ali Beitollahi an engineering seismology expert told Nature.
Ground water extraction to irrigate the thirsty land have formed fissures in various places.As per the research, Tehran’s rate of subsidence is recorded to be the highest in the world. Experts believe populations explosion, dam construction and droughts to be possible reasons behind subsidence.
Illegal drilling of wells is posing more threat to the downing levels of ground water. This has further raised the risk of sinking.
An estimated 100,000 illegal wells have been shut by government officials, but still 30,000 are left, reported Fox news.
Apart from Tehran, Venice, parts of western Texas, Louisiana’s coastal areas, San Joaquin Valley of California and the International Airport of San Fransisco are also affected by subsidence.
