TEHRAN – Iran’s government cabinet has approved the formation of a National Taskforce to Combat Subsidence, which will operate under the supervision of the First Vice President, to safeguard Isfahan’s historical monuments and world heritage sites, Amir Karamzadeh, head of the Isfahan Cultural Heritage Department, said.

According to Mehr news agency, he referred to the dimensions of the land subsidence crisis in the historical texture of Isfahan and the measures taken by the province's Cultural Heritage Department to combat this phenomenon.

“The issue of subsidence has been considered not only from the perspective of scientific circles but also at the level of the country's macro-management, and Isfahan's landmark buildings are seriously at risk.”

Although the announced subsidence rates in the historical areas of Isfahan have been set based on the scientific and expert studies, he added: “We have investigated the issue of subsidence in the field and in detail in cooperation with the Watershed Management Organization and the Governorate's Crisis Headquarters. Subsidence in the historical texture actually occurs, and its origin is the drying up of the Zayandeh River and the loss of material flow in the city.”

These aquifers fed underground water resources for centuries, but today, with widespread extraction and the cessation of the flow of the Zayandeh River, the underground aquifers have been emptied, resulting in holes in the ground that lead to subsidence, he pointed out.

“This taskforce will operate under the chairmanship of the First Vice President and is intended to provide basic solutions to contain this crisis. The formation of such taskforce shows that the issue of subsidence has gone beyond the borders of a province and has become a national concern.”

Karamzadeh added: “We in the province have proposed about 3,000 billion rials ($3.3 million) of credit for this area and sent it to the country's crisis management headquarters. We expect that with the serious support of Sardar Hossein Sajedinia as the head of this headquarters, appropriate financial resources will be allocated to prevent losses caused by subsidence. This is a national issue and the province's capacity to deal with it is not sufficient.”

“Our overall estimate shows that at least 1,000 billion rials ($1.1 million) of credit is needed to fully retrofit Isfahan's historical monuments against subsidence. This figure is estimated for the city of Isfahan alone and shows that the scope of the crisis is beyond local capacity.”

Expert studies show that the amount of subsidence in different buildings varies. From two to three centimeters in some places to 15 centimeters in parts of the historical texture has been recorded. 

He said that the greatest concern is related to Naqsh-e Jahan Square, Imam Mosque and parts of the historical bazaar. “For this reason, the issue of emergency reinforcement is a priority to prevent possible collapse. These measures are not temporary, but if implemented correctly, they can control the process of destruction.”

Karamzadeh pointed out the special vulnerability of Isfahan's historical minarets to subsidence and stated: “Minarets are at greater risk due to their special foundation and high height. If they tilt slightly or subsidence occurs under their foundations, the possibility of destruction increases greatly. For this reason, strengthening minarets should be put on the agenda more seriously. Strengthening the foundations from below and creating greater resistance to prevent tilting are among the measures that should be implemented.”

Karamzadeh emphasized: “If these measures are not taken in a timely manner, even a small earthquake can pose a serious risk to the minarets. Therefore, along with preventive measures against subsidence, attention should also be paid to seismic retrofitting. Experience from past earthquakes has shown that buildings with weak foundations have suffered the most damage.”

KD