TEHRAN – Only a limited number of Iran’s historical monuments are located in areas facing a high risk of land subsidence, and concerns about damage to heritage sites are often overstated due to confusion with ordinary structural settlement and moisture-related deterioration, a senior cultural heritage official said.

Mohsen Tousi, acting director general for the preservation, restoration and rehabilitation of historical buildings and sites at the Ministry of Cultural Heritage and Tourism, told IRNA on Monday that land subsidence remains a threat to cultural heritage but its actual impact is lower than commonly perceived.

“In technical terms, land subsidence is not inherently more dangerous than other hazards,” Tousi said. “It becomes critical when a historical monument is located on the edge of a subsidence zone or where different parts of the structure rest on soils with different stability.”

He said specialists assess risk by identifying cases in which part of a monument is built on subsiding ground while another part rests on stable soil, or where a structure lies along the boundary of a subsidence zone. In such cases, vulnerable buildings may require engineering intervention.

Tousi said extensive studies conducted in the central city of Isfahan showed that cracks found in several historic buildings were caused by moisture and the expansion and contraction of clay soils rather than land subsidence.

He said many concerns about subsidence stem from confusion with ordinary building settlement, which occurs because of structural weight, soil characteristics and moisture conditions. Similar damage may also result from collapsed qanats, stormwater wells, sewage pits or broken water and sewer pipes, he added.

“These types of settlement should not automatically be attributed to land subsidence,” Tousi said.

He said subsidence zones have been mapped and incorporated into urban planning data, with the results showing that very few historical monuments are located within high-risk areas.

Tousi also said Iran’s deputy minister for cultural heritage is pursuing the establishment of a specialized task force on land subsidence to strengthen scientific monitoring of heritage sites using modern technologies.

He underlined the importance of documenting historical monuments to improve disaster preparedness, noting that the Iranian plateau has experienced frequent earthquakes throughout its history. “We document heritage sites so that, if earthquakes or ground changes occur, we have the necessary information to protect and restore the country’s cultural heritage.”

He added that where traditional materials cannot provide sufficient structural reinforcement, modern engineering technologies and supporting structures should be used alongside historic buildings to improve earthquake safety while preserving the monuments.

AM