Yangon city expansion raises a quake challenge

17 October 2016
Yangon city expansion raises a quake challenge
Photo: Hong Sar/Mizzima

Yangon’s population looks set to almost double within the next thirty years. But as property developers rub their hands in anticipation, it is crucial to keep public safety at the forefront and recognise that Myanmar’s commercial hub lies in an area prone to earthquakes.
As Myanmar seeks growth and development as the country continues to open up, earthquake experts and disaster risk consultants note the importance of being aware of the dangers of a serious earthquake. There are two main issues to keep in mind. Firstly, construction techniques for houses, high-rise buildings, and for infrastructure including bridges and dams, need to take into account the earthquake threat. And secondly, owners and occupants of existing buildings, particularly colonial era property, need to beware of potential dangers of buildings that might be in poor repair, as well as the questions of how to react should a quake strike – in other words, should they try to exit the building or take cover in the building.
During the recent Earthquake Forum Yangon, organised by ActionAid, one of the issues raised was how unpredictable though inevitable earthquakes are in Myanmar and in South Asia as a whole.
The uncertainty is a problem. As 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 hit Myanmar.
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 says. “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,” says Mr Murugesan.
As Mizzima has previously reported, 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.
Up until now, building standards have been slack in Myanmar, and property erected over half a century ago might fail modern-day quake standards. In the past, population levels were far lower than today, and many of the urban sprawl consisted of houses made of bamboo – flimsy, admittedly, but typically less dangerous to occupants in the case of collapse.
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 says.
Homes built in say Europe or North America are normally 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 says.
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 Myanmar’s new government to not renew the project.
China Power Investment Corporation, the main contractor and financial backer, 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 remains unclear, though a commission has been assigned to look into this. Planned dams on the Salween or Thanlwin River are also the subject of heated debate.
Unlike other natural disasters such as flooding and drought, which make an appearance virtually every year, serious earthquakes are less predictable and therefore it is harder to galvanise people into action. Much will depend on the government and regional authorities to take action in terms of building standards and quake preparedness.