KARACHI: Eighty-seven per cent of buildings in Gulshan-i-Iqbal will experience extensive or complete damage if an earthquake of moderate to high intensity strikes the city. Bridges, however, will largely remain safe. This information is part of an extensive study covering nine countries; Turkey, Iran, Jordan, Georgia, Armenia, Pakistan, Azerbaijan, Lebanon and Cyprus.

Titled “Earthquake model of the Middle East region: hazard, risk assessment, economics & mitigation”, it was conducted between 2009 and 2013 by a number of institutions and funded by Japanese Tobacco Institute.

According to the study, the Middle East region is located at the junction of major tectonic plates, namely the Indian, Arabian and Eurasian plates, resulting in very high tectonic activity. Some of the major earthquake disasters in human history occurred in the Middle East, affecting most countries in the region.

Being one of the most seismically active regions of the world, the Middle East, extending from Turkey to India, is also an important region in terms of urbanisation, energy reserves and industrialisation trend.

The region involves the world’s most populated capitals and cities with huge economic importance such as Istanbul, Baghdad, Tehran, Jeddah, Riyadh, Cairo, Kabul, Karachi and Lahore.

The Pakistan section of the study was carried out by the Department of Earthquake Engineering of the NED University of Engineering and Technology.

The research team headed by professor and dean of civil engineering and architecture, Dr Sarosh Hashmat Lodi, has collected seismic hazard data from all over Pakistan but its focus has been on Karachi and then on Gulshan-i-Iqbal town, which has been chosen as a test case.

It is the first scientific study in the country which deals with the loss estimation of different structures due to an earthquake.

One of the reasons for choosing Karachi and its particular town, the study says the city is the third most congested cities in the world with a population density of over 4,000 per square km. And, though, the city has never been hit by a near-field earthquake in its recent history, tremors are commonly felt in Karachi due to far-field earthquake events.

“In the past 200 years there have been six earthquakes with magnitudes greater than 7 in the surrounding regions of Karachi, which were felt in Karachi but did not cause any noticeable damage,” it says.

The Gulshan town is located in the central part of the city bounded by Lyari River from one end. The town has an area of about 65 square kms, (8pc of the city’s total built-up area) and comprises 13 union councils.

According to the report, the loss estimation for the Gulshan town is conducted for five possible earthquake scenarios. Eighty-seven per cent of the 81,751 buildings in Gulshan town will suffer extensive or complete destruction if an earthquake generating moderate to high ground acceleration occurs in the city whereas 219 pipelines will suffer extensive to complete damage. Only three per cent of the total 199 bridges will suffer extensive damage or collapse.

Eighty-five per cent of the buildings in the town, according to the report, have reinforced concrete frames. This building type is further classified in five types based on the number of storeys. It is observed that 81pc of all reinforced concrete buildings consist of one, two, three and four storey frames.

The building, bridges and lifeline damage was evaluated through simulation using ELER (Earthquake Loss Estimation Routine). The building inventory was developed for the town with the help of video survey using RoadEye, physical survey and estimation. “It wasn’t practically possible to collect such a data of the entire city due to limited funds. But, one could easily conclude from the research findings that the city, by and large, is at risk of facing similar damages as the physical infrastructure in other parts of the city is not so different,” said Mr Lodi.

“The results of the loss estimation for the buildings, bridges and pipelines clearly indicate that there is a need for revisiting the existing design provisions. In particular, the seismic hazard for the city needs to be updated in light of current developments. Simultaneously, retrofit strategies for the structures and pipelines should be devised to avoid the predicted damages to the existing infrastructure,” he added.