Bangladesh

Earthquake resilience: No updated data on city buildings

 earthquake risk Dhaka city
Photo: Amran Hossain

If there is anything that some of the most major fires have pointed out, it is that very few buildings in the capital are built following the National Building Code.

But unlike large fires, there has, thankfully, been very little chance to test out just what this non-adherence to the code would mean in the event of a major earthquake.

The line has been said so many times that it has become a trope – the level of unplanned urbanisation in Dhaka is such that a large earthquake would crush the city.

But there is little data on this vulnerability.

The last data regarding the vulnerability of the city is from 2010 when Stanford University evaluated the earthquake risk of cities around the world and assigned an index.

Dhaka was ranked to be among the world's 20 cities most vulnerable to earthquakes.

In a 2020 report presented to the Asian Disaster Reduction Center by the disaster management ministry, the government said that around 250,000 buildings in the three major cities of Dhaka, Chattogram, and Sylhet are extremely vulnerable to earthquakes.

The report said that 24 percent of the buildings in Dhaka, 46 percent in Sylhet and 79 percent in Chattogram were detected as risky.

But all of this data is from 2009. The capital city has been expanding at a rate of 3.3 percent every year for the last two decades.

Rajdhani Unnayan Kartripakkha has checked 3,252 school buildings in the city and found 90 percent of them to be not resilient to earthquakes.

This assessment is only a drop in the ocean.

In his budget speech for 2022-23, Finance Minister AHM Mustafa Kamal pointed out that an earthquake vulnerability assessment for buildings in Dhaka city is going on under the Urban Resilience Project.

Adil Mohammed Khan, the executive director of Institute of Planning and Development, said that under the project, a risk assessment of Dhaka is being done and will be completed by this year.

"The next challenge will be to turn this knowledge into a plan for the city," said Adil.

But time is ticking. When it comes to earthquakes, experts fear the calm.

From 2020 till now, there were 27 small earthquakes in Bangladesh and its immediate surrounding regions of Meghalaya, Tripura, West Bengal and Assam. Not one of them was above 5.3 on the Richter Scale.

"The effect of high-slip-rate of Duaki fault could be observed as the largest seismic hazard in Bangladesh," said the report.

According to an article published in The Daily Star by Shashanka Saadi, the head of emergency preparedness & response programme, Brac International, it is Bangladesh's unique position at the juncture of three tectonic plates that puts it at risk. This includes the Indian plate to the west and southwest, the Tibet sub-plate to the north, and the Burma plate to the east.

"Moreover, the plate boundary between India and Burma passes through Bangladesh and these tectonic blocks were responsible for many earthquakes in the past. For us, some major faults should be noted due to their potential for giving way to devastating earthquakes: Bogra Fault, Tripura Fault, Dauki Fault and Assam Fault Zone. All of these can produce earthquakes of a magnitude of 7 to 8.5," said the article.

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Earthquake resilience: No updated data on city buildings

 earthquake risk Dhaka city
Photo: Amran Hossain

If there is anything that some of the most major fires have pointed out, it is that very few buildings in the capital are built following the National Building Code.

But unlike large fires, there has, thankfully, been very little chance to test out just what this non-adherence to the code would mean in the event of a major earthquake.

The line has been said so many times that it has become a trope – the level of unplanned urbanisation in Dhaka is such that a large earthquake would crush the city.

But there is little data on this vulnerability.

The last data regarding the vulnerability of the city is from 2010 when Stanford University evaluated the earthquake risk of cities around the world and assigned an index.

Dhaka was ranked to be among the world's 20 cities most vulnerable to earthquakes.

In a 2020 report presented to the Asian Disaster Reduction Center by the disaster management ministry, the government said that around 250,000 buildings in the three major cities of Dhaka, Chattogram, and Sylhet are extremely vulnerable to earthquakes.

The report said that 24 percent of the buildings in Dhaka, 46 percent in Sylhet and 79 percent in Chattogram were detected as risky.

But all of this data is from 2009. The capital city has been expanding at a rate of 3.3 percent every year for the last two decades.

Rajdhani Unnayan Kartripakkha has checked 3,252 school buildings in the city and found 90 percent of them to be not resilient to earthquakes.

This assessment is only a drop in the ocean.

In his budget speech for 2022-23, Finance Minister AHM Mustafa Kamal pointed out that an earthquake vulnerability assessment for buildings in Dhaka city is going on under the Urban Resilience Project.

Adil Mohammed Khan, the executive director of Institute of Planning and Development, said that under the project, a risk assessment of Dhaka is being done and will be completed by this year.

"The next challenge will be to turn this knowledge into a plan for the city," said Adil.

But time is ticking. When it comes to earthquakes, experts fear the calm.

From 2020 till now, there were 27 small earthquakes in Bangladesh and its immediate surrounding regions of Meghalaya, Tripura, West Bengal and Assam. Not one of them was above 5.3 on the Richter Scale.

"The effect of high-slip-rate of Duaki fault could be observed as the largest seismic hazard in Bangladesh," said the report.

According to an article published in The Daily Star by Shashanka Saadi, the head of emergency preparedness & response programme, Brac International, it is Bangladesh's unique position at the juncture of three tectonic plates that puts it at risk. This includes the Indian plate to the west and southwest, the Tibet sub-plate to the north, and the Burma plate to the east.

"Moreover, the plate boundary between India and Burma passes through Bangladesh and these tectonic blocks were responsible for many earthquakes in the past. For us, some major faults should be noted due to their potential for giving way to devastating earthquakes: Bogra Fault, Tripura Fault, Dauki Fault and Assam Fault Zone. All of these can produce earthquakes of a magnitude of 7 to 8.5," said the article.

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