Bangkok sinking faster -urgent action needed

[chingching]

Thailand needs to act as Bangkok sinks faster | Environment | DW.DE | 02.05.2013

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Thailand's capital Bangkok has been sinking for years and time is running out to tackle the problem. As the ground continues to subside by 3 centimeters (1.2 inches) a year, scientists say action is urgent.

The government has been ignoring the fact that Bangkok is sinking for years,
scientists in Thailand said.

According to the national agency that provides satellite images to update on disasters like the 2011 floods, Bangkok's problem may be even worse than previously thought. The city of 10 million people could be sinking faster; and experts warn there are only seven to 10 years left to tackle the problem.

"The buildings are already sinking nearly 20 millimeters.

Additionally, the soil and clay are also sinking 10 to 20 millimeters," said Dr Anond Sanitwong, director of GISTDA, the Geo-Informatics and Space Technology Development Agency.

"Adding those two figures together means the absolute sinking rate of the ground is around three centimeters or 30 millimeters at least per year. It's fast - much faster than we thought."
Previous floods have left huge cracks in Bangkok's street
Sanitwong warns that - considering the devastation caused by the 2011 floods - the latest data is a major cause for concern. "It doesn't mean the whole area is going to be flooded, but it does mean, especially during high tide, we are going to have a big problem with drainage."

According to Sanitwong, more than 50 percent of the sinking has been caused by the tapping of groundwater by industry. Although the practice has been banned, it still goes on. The sheer weight of all the modern buildings that fill the Bangkok skyline are also contributing to the problem.

Created and undone by climate change?

"A thousands years ago, all of Bangkok was flood land," Sanitwong explains, pointing out that the 230-year-old city itself only exists because of historic climate change.

"Somehow over a certain period, we had more than average strong winds and waves. Those strong winds and waves from the sea moved the sand and soil and accumulated in this area and it became Bangkok."

The city is therefore particularly sensitive to any alterations in the climate and seriously at risk should anything change again.

"We believe we are in the phase where we have less strong winds and storms in this particular area. So thus no more mechanism to bring in the sediments and the clay from the sea, the ocean," Sanitwong warns.

And that means Bangkok is also threatened by the rising sea level.

Historic buildings particularly at risk

Scientist Art-Ong Jumsai, former Deputy Minister for Foreign Affairs and currently Director of the Institute for Sathya Sai Education, has been warning successive Thai governments about the problem for years. But he says his dire predictions have fallen on deaf ears.

Many historic sites - like this temple - are especially at risk

"Nobody is taking the lead in the government. They are only looking at the next election. And people don't like to hear this. The government has to consider business interests, it also wants to attract more tourists. So they don't want people to talk about anything that is negative."

With even more shopping malls opening and a boom in high-rise condo developments across the city, officials are fearful of spooking investors.

And while modern buildings are built with foundations running several meters into the ground, the city's temples and historic structures don't have the same support.

"The ancient buildings are in greater danger because they don't have the foundations," Jumsai explains. "Many temples are having problems because the water has come up and is encroaching on them.

In Ban Khun Tian which is a part of Bangkok one temple is in the middle of the sea with the water level right up. So they have already lost the lower level of the temple itself."

How to fight the problem?

Scientists are divided though on how to tackle the problem. Some have suggested better management of building land. One radical idea suggested the capital be moved to the north of the country. Others suggest that natural defences like mangrove swamps are strengthened along the Bay of Bangkok.

Modern skyscrapers add to the problem as they are heavy on the ground

Jumsai thinks officials need to build a series of huge dikes along the Gulf of Thailand. He says a multi-billion dollar investment is required to protect Bangkok in the same way the Netherlands - which is also below sea level - protects itself from natural disasters.

"In order to prevent the flooding of the central area of Thailand, it's not just Bangkok, it's a huge area where we have a lot of agriculture, we need a wall along the seafront and this will prevent flooding in the future. If we can pump out water over the wall in the future, this will solve the problem for many years to come."

Scientists don't have to go far for further proof that Bangkok is sinking.

At Chulalongkorn University in the centre of Bangkok, many of the 50- to 100-year-old buildings have a marked line about 50 centimeters up showing where the ground level once was.
DW.DE

[chingching]

10 years = 12 inch drop

[Loy Toy]

They have been discussing this problem for the last 27 years I have been here and that is why they are going to move the capital on to the Eastern Seaboard.

Already most of the major manufacturing plants have left greater Bangkok and the port at Klong Toey is slowing being shut down in favour of the other 2 sea ports at Lam Chabang and Rayong.

Bangkok is a logistic nightmare to do anything and the sooner it sinks the better.

I can see it happening.......PATTAYA: THE CAPITAL OF THAILAND........

[Bazzy]

Modern skyscrapers add to the problem as they are heavy on the ground

Don't they dig down and put the foundations into the bedrock? I am not an engineer....

[chingching]

no theres no bedrock just sludge ! they build a concrete raft say 30 feet down and piles down another say 75 feet down but they can shift like the condo by the river in nonthaburi that slipped sideways so the building was like the leaning tower of Piza...

[Rainfall]

What's the matter with the Thais, can't they think things trough and do a couple of tests? Hitler who planned to fill Berlin with hideous buildings had this thing here erected in Berlin.



A heavy load bearing body, a concrete monolith of nearly 13,000 tons of weight on 100 square metres of ground, or 13 Kilo per square cm. The thing subsided 19 cm in 2 1/2 years, and canted by 3 degrees, and that's why Berlin has very few highrises. That's how it's done in the developed countries.

[DJ Pat]

I read that the Skytrain pillars go down at least 50 metres, as it's a regulation.

[hillbilly]

Modern skyscrapers add to the problem as they are heavy on the ground

Don't they dig down and put the foundations into the bedrock? I am not an engineer....

I actually talked to the Brit who was in charge of building Swampy's runways. He said that they tried to find bedrock but gave up after 400 meters.

True or not, I have no idea.

[can123]

I read that the Skytrain pillars go down at least 50 metres, as it's a regulation.

Which Thailand are you talking about ? It's a regulation !

[Lorenzo]

Bangkok is a logistic nightmare to do anything and the sooner it sinks the better.

I can see it happening.......PATTAYA: THE CAPITAL OF THAILAND........

As it should be!!

[chingching]

looks like the subway will have a short lifespan unlike the London subway which is over 100 years of age.
is the subway sinking too ?

[ENT]

Modern skyscrapers add to the problem as they are heavy on the ground

Don't they dig down and put the foundations into the bedrock? I am not an engineer....

I actually talked to the Brit who was in charge of building Swampy's runways. He said that they tried to find bedrock but gave up after 400 meters.

True or not, I have no idea.

As far as I know its all silt over mud over mudstone over sand then sandstone below that overlying true bedrock of quartzite, gneiss and granitic gneiss at 500 metres depth.

All above that is sedimentary deposit coming down from upstream of the Chao Phraya river for millions of years. Wh

What keeps it all soft is a series of aquifers feeding to the sea.
The top sedimentary level extends about 10 < 30 metres depth below SL.

It's all a vast potential swamp.

In my estimation, the capital should be shifted to the N East, or a wall built across the Chao Phraya delta area to act as a barrage or dyke system. That wall would have to be around 75 kilometres long and up to one kilometre high from base to top.

If that were to occur it could double as a marine tide electicity generator on both incoming and outgoing tidal flows so offsetting the cost of building the wall.

[Tom Sawyer]

Modern skyscrapers add to the problem as they are heavy on the ground

Don't they dig down and put the foundations into the bedrock? I am not an engineer....

A friend of mine knew a structural engineer at AIT who told him the quiet concern is over a major earthquake anywhere near Bangkok. Because all those hi rise buildings can't reach bedrock 'they guess" how far down to drive foundations. He said a shallow strong quake and liquefaction could destroy the city and kill hundreds of thousands

[ENT]

That's a fact. Liquefaction is the single most probable result there in a quake of M 7.

Thailand's had a run of tremors over the last few years and many medium height buildings have started to lean or slip sideways.

The Leaning Tower of Pathumthani, leaning at 40 degrees, could rival the Leaning Tower of Pisa.


The owners filed for permission to demolish it this week.

There's a few more on the endangered list.

[cheekyman]

Great thread and good info - thanks guys

[DJ Pat]

Bangkok Subway was built as a solid concrete object totally flood resistant, apparently.

The London Underground was built using innovative methods - In the 1920s

[chingching]

not all of it, some lines were built more recently .

[Tom Sawyer]

Bangkok Subway was built as a solid concrete object totally flood resistant, apparently.

The London Underground was built using innovative methods - In the 1920s

Even earlier - 1860s

History &#124; Transport for London