The Global Urbanist

News and analysis of cities around the world

As if climate change flooding wasn't enough: preparing Dhaka for a major earthquake

Aware that an earthquake like Haiti's could strike Dhaka, a city seven times more populous, engineers and government leaders in the Bangladeshi capital are discussing how to reinforce buildings and prepare emergency services, to prevent tragedy on an unimaginable scale.



Cities: Dhaka

Topics: Emergencies and reconstruction, Health and aging, Earthquakes

Densely populated Dhaka, which lies dangerously close to a major fault line, comprises thousands of shoddily engineered buildings at risk of collapse in a powerful earthquake, experts warn.

Almost 80,000 buildings would be destroyed if a 6.0-magnitude tremor originated beneath Dhaka, according to a government study. A 7.5-magnitude shake from the Madhupur Fault, 140km away, would kill 130,000 people instantly and cause structural damage worth US$1.1 billion.

"Dhaka will be hit by a major earthquake in the future, but nobody knows exactly when. It could happen any time. It could happen tomorrow or in 50 years," said Mir M Ali, professor and chairman of the structures division at the University of Illinois School of Architecture.

Bangladesh recently topped the 2010 Natural Disasters Index, compiled by the Maplecroft research group.

Tectonic plate activity beneath Bangladesh has a lot of people worried and the Department of Geology at Dhaka University says the city is moving 30.6mm a year. "If something happens, it will cause a major catastrophe. People will be killed, infrastructure will be destroyed," Ali said by telephone from Dhaka during a recent visit.

However, Ahsan Zakir, director-general of the government's Disaster Management Bureau, said the government was slowly but surely getting the city and its people in shape to respond to an earthquake.

"We are preparing volunteers and we are looking to buy some equipment for search and rescue, search cameras, scavengers, locator systems," he said. "We are raising public awareness. We are doing workshops as a continuing process and training volunteers. We have already trained 1,000 volunteers and there will be 60,000."

The UN Development Programme in Bangladesh has contributed $40 million for disaster preparedness activities that will begin in August.

Rife with weak buildings

The prevalence of "soft-storey" buildings on shaky foundations above garages or open commercial spaces poses a significant problem.

"They are often built with a garage in the lower floor, and then you have an apartment complex above. This creates a very weak storey at the ground level," Ali said.

The Dhaka metropolitan area has a population of 13 million, growing at about 4.2 percent a year, all crammed into 300 sqkm.

Unplanned development is rife, and most structures are non-engineered. Developers often ignore building regulations to cut costs.

"The problem is the way Dhaka has grown over the last 50 years. Unplanned urbanisation and construction of buildings have not followed regulations. It's a very risky way to build," said Dilruba Haider of the Bangladesh Disaster Preparedness Centre.

With the city so densely packed, responding to emergencies is difficult - as evidenced this month when a fire ripped through apartment blocks, killing up to 150 people as rescue workers struggled to navigate the narrow streets. There have also been a number of building collapses in Dhaka recently, including on 2 June when a four-storey building crumbled, killing 25.

Earthquake proofing

A few basic engineering steps could reduce the risk of disaster.

"They can minimise some of the problems by developing some kind of extra bracing system, but this will not be easy because there are so many buildings," Ali said. "For the soft-storey buildings you could [reinforce] the low storeys."

While earthquake-proof buildings can be a selling point for high-end property developers, getting other developers to spend extra money on toughening up their structures will be tricky.

"This time the government is taking it seriously. There are a lot of at-risk buildings, so the government has to take some action. Right now they are trying their best, but from one week to the next, we don't know what will happen," said Mehedi Ahmed Ansary, professor at theBangladesh University of Engineering and Technology's department of civil engineering.

"The emergency services are not in very good shape. The capacity of the hospitals is not enough. If there is a disaster they would not be able to cope. The fire service has capacity, but it has limited resources and funding."

In the event of an eight magnitude quake, Dhaka has enough hospital beds to handle only about two-thirds of the casualties expected, a government study found.

Source: the humanitarian news and analysis service, IRIN