Poor engineering and the use of floodplains for building construction could contribute to the economic and human costs of a strong earthquake hitting Dhaka city, a leading expert has warned.
Bangladesh University of Engineering and Technology (BUET) Professor Mehedi Hasan Ansari told the Dhaka Tribune that Bangladesh is “waiting for a strong earthquake like in 1897”, which had an estimated magnitude of 8 on the Richter scale.
“In addition to faulty building construction practices, the rapid use of the city’s floodplain will play a role in possible building collapse and subsequent human causalities, if an earthquake of 7.5 magnitude hits Dhaka,” the professor said.
According to the ‘Dhaka Profile and Earthquake Risk Atlas’ study conducted in 2014, around 50,000 deaths and up to $5.7 billion in damages could result from an earthquake of magnitude 7.5 striking the capital.
The study was based on a probable model of a 7.5-magnitude tremor along the Madhupur Fault line and was conducted by the Bangladesh Urban Earthquake Resilience Project with assistance from the World Bank and Earthquakes and Mega-cities Initiatives (EMI).
The research data estimated that around 88,000 buildings - over one quarter of the total in Dhaka - will be extensively damaged. DNCC could suffer the collapse of up to 54,000 buildings, while DSCC could face the collapse of 34,000 buildings.
The study further showed that Dhaka North City Corporation (DNCC) could face an estimated bill of around $3.4billion, while the Dhaka South City Corporation (DSCC) might suffer damages of around $2.2 billion.
The study identified several aspects of construction which could compromise the structural integrity of buildings during a quake.
These include soft-story, flat slab, heavy overhang, torsional irregularity, slender and short column, non-parallel system, poor concrete, insufficient gap, non-structural vulnerability, soil liquefaction, narrow access and absence of fire protection.
In addition to a projected 50,000 deaths, the 2014 study estimated around 200,000 injuries resulting from a large quake..
Emphasis on first responders
The government has recruited 62,000 ‘urban community volunteers’ to act as first responders in the event of a disaster, of which 36,000 have already been trained.
Major Shakil Newaz, director (Operation and Maintenance) of Fire Service and Civil Defense, said that in addition to the volunteers, the government has already procured the equipment needed to run a proper rescue operation from collapsed or damaged buildings.
In collaboration with the government’s Housing and Building Research Institute (HBRI), the Disaster and Relief Ministry’s Comprehension Disaster Management Programme is also conducting training programmes for masons and builders to make the new buildings more resilient to tremors.
Apart from this, the government has already taken the initiative to retrofit buildings such as hospitals and important government infrastructures, for minimising probable damages, HBRI sources said.
Dr Md Humayun Kabir, a professor in Department of Geography and Environment of Dhaka University, told the Dhaka Tribune that he was unsure how effective the training and equipment would be in the event of a major disaster.
“In my personal opinion, all the initiatives taken could be in vain, as we do not have any prior experience to deal with a disaster of this level, and large road networks are needed to run the rescue operation,” he said.