City growth could mean more quake casualties

City growth could mean more quake casualties

If a major earthquake hits and you are living in a bamboo hut, chances are you will come out unscathed. But if you are in a concrete house or office, the potential danger is greater. 

This is the reality today for Myanmar as it chases its mantra of growth and development. As earthquake experts and disaster risk consultants note, the growth of cities can have its downside if a quake strikes. Construction techniques for houses, high-rises, and for infrastructure including bridges and dams, needs to take into account Myanmar’s earthquake threat.

- See more at: http://www.mizzima.com/news-features/city-growth-could-mean-more-quake-casualties#sthash.SKOUKT0N.dpufAs Jaiganesh Murugesan, Disaster Risk Reduction Specialist at the United Nations Human Settlements Programme, explains, it is hard to predict when the next serious earthquake will strike Myanmar. But the danger is real and the country is not effectively prepared, both in terms of infrastructure standards and in the necessary drills on how to react.

“Myanmar has not had any major damaging earthquake since the middle of the 19th Century when a quake of 7 on the Richter scale struck,” Mr Murugesan said. “While the majority of the country is prone to earthquakes, experts note that there are seismic gaps along the Sagaing fault where one can expect the next potential earthquake in the range of (7 or 7.5 on the Richter Scale). However, it also depends on the return period. Experts say the return period of an earthquake along the Sagaing fault varies between 80-160 years and on average 100 years after an earthquake.”

Even seismologists are unable to predict when the next “big one” will strike.

“An earthquake can happen early on or even later than that as earthquakes cannot be predicted, but they estimate based on studies,” Mr Murugesan from UN-Habitat. The organisation has undertaken earthquake risk assessments for a number of major cities in Myanmar as well as a seismic hazard assessment in Yangon in collaboration with various partners, under the European Commission-funded Myanmar Consortium for Community Resilience (MCCR).

Concern has been voiced that quakes of five or more on the Richter scale could have a devastating effect on infrastructure, particularly in cities where building standards may be slack or when it comes to old buildings, like many in Yangon built well over half a century ago.

As Mr Murugesan says it is important to bear in mind that in the past the population levels were lower and many people used to live in houses made of bamboo.

Things have changed. “We have big cities along the Sagaing fault and a major earthquake along the fault that can cause severe damage and destruction,” he said.

Census data over the last 40 years or more shows population density in Yangon has increased 2.5 times and Mandalay has seen a doubling of growth.

This means the population is in a state of “high exposure” should a serious quake hit.

Mr Murugesan says the concerns lie in other cities such as Yangon and Mandalay. City development committees have bylaws for building construction in cities, enacted after 2012.

“Looking at the current system, earthquake resistant designs are reviewed only for buildings taller than three stories and specific high-rise buildings have to be approved by the Committee for Quality Control of High Rise Buildings. However, one cannot make any specific guess on what is actually on the ground, as many of the low-rise buildings are built without the support of engineers or supervision of engineers, while also not taking into account the earthquake risk,” he said.

Homes built in say the UK or United States are subject to tough building standards. But many houses in Myanmar are built without careful standards or checks.

“Even if they have considered the earthquake design based on the available information, with the availability of new information, the seismic zones have changed considerably. So the building is not designed to the latest requirements,” Mr Murugesan said.

Building construction is not the only cause for concern. Worries have been voiced over such structures as hydropower dams that could be prone to serious damage in the event of a major earthquake. 

The Myitsone Dam project, for example, was put on hold by President Thein Sein in 2011 over humanitarian and environmental concerns.  Yet the fear over earthquakes is one of the drivers of an ongoing call by NGOs to the new government, when it comes in, to not renew the project.

China Power Investment Corporation, the main contractor and financial backer, expects the project to recommence after President Thein Sein’s tenure finishes. The company claims the dam would be built using modern construction standards and would be safe.

The NGO International Rivers has warned of the dangers of building large dams in earthquake-prone areas of Myanmar, particularly the Myitsone Dam and planned dams on the Thanlwin or Salween River.

“If the Myitsone Dam were to break during an earthquake, it would endanger the lives of hundreds of thousands of people by flooding Kachin State's largest city, Myitkyina,” according to the NGO.

How Myanmar’s new government will handle the case of the Myitsone Dam is unclear. While plans for dams continue on the Salween River, this dam has been subject to heated opposition and debate.

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