Experts warn of serious danger to Bangkok if efforts not made to check shoreline erosion

By PRATCH RUJIVANAROM 
THE SUNDAY NATION

 

 

SUBSIDENCE CAUSED by human activities in Bangkok Metropolitan areas is the most important factor causing shoreline erosion in the Bay of Bangkok, followed by rising sea levels, a recent study has shown.

However, experts advise against constructing hard structures to prevent erosion, which could instead intensify the problem, and instead focus on mangrove reforestation to address the problem.

 

Looking through a thin layer of mangrove forest along the coastline of Samut Prakan’s Phra Samut Chedi district, observers can see a small temple situated on a bizarre seaside. The temple is Wat Khun Samutchin, a relic of an old community that has sunk into the sea, a clear sign of the danger that shoreline erosion poses to Metropolitan Bangkok.

 

Thanawat Charupongsakul, director of Thailand Global Warming Academy, outlined the challenges of coastal erosion on a field trip last Thursday to Wat Khun Samutchin in one of the worst-hit areas of coastal erosion. The inner Gulf of Thailand, especially the 120 kilometres of the northernmost shoreline of Samut Prakan, Bangkok, Samut Sakhon and Samut Songkhram, is particularly vulnerable to erosion and sinking into the sea, he said.

 

Thanawat added that the shoreline erosion rate of the area was as high as 30 metres per year. If no action is taken, 150,000 rai (24,000 hectares) of land could consumed by the sea over the next 50 years. With such rapid changes underway, this is a problem that everyone, especially residents of Bangkok, should consider, Thanawat said.

 

“From my study, subsidence contributes to 68 per cent of the current problem of shoreline erosion, along with 16 per cent due to the sea level rising, 6.8 per cent from a lack of sedimentation, and 2.4 per cent from river delta dredging,” he said.

 

“These factors are all the result of human activities, especially the subsidence, which is mainly a result of urbanisation of the Bangkok Metropolitan area.”

 

Surajit Chirawate, a former Samut Songkhram senator, said that if people were serious about preventing Bangkok from sinking into the sea, they needed to move away from using hard structures such as concrete sea walls, jetties and breakwaters. Not only would such structures fail to solve the problem, they would actually intensify the impact of coastal erosion on nearby areas, he said.

 

“We have a problem. Authorities do not understand nature and construct hard structures to protect the coastline, which has already proven ineffective in places such as Rayong’s Seangchan Beach and Songkhla’s Samila Beach.”

 

Hard structures make waves stronger, which then dig out the sediment from beneath the structure and intensify erosion, he said. However, there are alternatives including soft structural barriers such as bamboo fences that break the wave force and trap sediment behind the fence line.

 

“The entire coastline of Samut Songkhram uses bamboo fence as a wave breaker and we found that it is a cheap and effective way,” he said. “We found that the sediment built up rapidly behind the fence, and then we grew mangrove forests to hold together the land we reclaimed.”

Such solutions were cheaper than hard structures, he added.

 

“The budget for a bamboo fence is only about Bt8 million per kilometre, and we could significantly reduce the cost to Bt2 million per kilometre if authorities let local people build their own defensive bamboo fences. We just need to repair the fences every three years,” Surajit said.

 

According to the coastal erosion database compiled by the Thailand Coastal Spatial Database System of Geo-Informatics and Space Technology Development Agency, Samut Prakan’s Phra Samut Chedi district has suffered the most erosion over the past 10 years, with up to 390 metres wide of shoreline lost since 2005.

 

In contrast, Tambon Klong Khon of Samut Songkhram reclaimed up to 270 metres wide from the sea since 2005.

 

Preserving a healthy mangrove forest also helps protect the coast from erosion, which can be demonstrated by Google satellite imagery.

Images show a lush mangrove forest in Tambon Klong Khon, while in contrast the coast of Phra Samut Chedi district has been left with only a thin line of mangrove forest, where there is any at all.

 

Source: http://www.nationmultimedia.com/detail/national/30324327

 

 

-- © Copyright The Nation 2017-08-20

20 minutes ago, rooster59 said:

Hard structures make waves stronger, which then dig out the sediment from beneath the structure and intensify erosion, he said. However, there are alternatives including soft structural barriers such as bamboo fences that break the wave force and trap sediment behind the fence line.

This is how the rest of the world builds wavebreakers....and yes they are hard structures made of concrete and do break the waves...i mean real waves, not those tiny wrinkelings they have in Thailand.

 

Have fun with the bamboo fences in sea 

Edited August 19, 20178 yr by Thian

The sooner nature takes care of Bangkok the better.

In 50 years, TAT will be promoting glass bottom boat tours of what was once Bangkok. lol

 

doubt thai govt ever reacts along the lines of academic suggestions

Now and then i have seen lofty plans mentioned in the newspapers regarding this.

 

Ideas of building a sea barrier similar to what they have done outside Venice, Italy.

Stretching all the way from Sattahiip to Cha Am / Hua Hin.

 

The arrangements in Italy were extremely expensive.

 

What I have seen mentioned here is a sea barrier of huge dimensions compared to Italy.

Would be extremely costly.

 

Bangkok under water or moving the capital would also be extremely costly.

 

7 minutes ago, melvinmelvin said:

Now and then i have seen lofty plans mentioned in the newspapers regarding this.

 

Ideas of building a sea barrier similar to what they have done outside Venice, Italy.

Stretching all the way from Sattahiip to Cha Am / Hua Hin.

 

The arrangements in Italy were extremely expensive.

 

What I have seen mentioned here is a sea barrier of huge dimensions compared to Italy.

Would be extremely costly.

 

Bangkok under water or moving the capital would also be extremely costly.

 

Move back to the former city, Bangkok is doomed. In maybe 100 years

45 minutes ago, spiderorchid said:

Move back to the former city, Bangkok is doomed. In maybe 100 years

Right, I'll make a note not to be here then !

SUBSIDENCE CAUSED by human activities in Bangkok Metropolitan areas is the most important factor causing shoreline erosion in the Bay of Bangkok, followed by rising sea levels, a recent study has shown.

However, experts advise against constructing hard structures to prevent erosion, which could instead intensify the problem, and instead focus on mangrove reforestation to address the problem.

 

In the furthest reaches of your imagination, I ask you- is it possible to imagine the Thai government doing something progressive, preventive, visionary, or far reaching? Planting mangrove swamps? How would one even go about doing that? Which agency would take charge? Why worry about tomorrow? Why spend the money, when it can be enjoyed today, by fabulously wealthy officials, and army men? 

This is how the rest of the world builds wavebreakers....and yes they are hard structures made of concrete and do break the waves...i mean real waves, not those tiny wrinkelings they have in Thailand.
 
Have fun with the bamboo fences in sea 

Don't be too dismissive. Mangroves are the way to go in tropical areas - cheap and effective. What he is saying makes sense. And he's given a good example to illustrate it.

7 hours ago, rooster59 said:

“From my study, subsidence contributes to 68 per cent of the current problem of shoreline erosion, along with 16 per cent due to the sea level rising, 6.8 per cent from a lack of sedimentation, and 2.4 per cent from river delta dredging,”

After reading this, the PM wrote a poem.

7 hours ago, Thian said:

This is how the rest of the world builds wavebreakers....and yes they are hard structures made of concrete and do break the waves...i mean real waves, not those tiny wrinkelings they have in Thailand.

 

Have fun with the bamboo fences in sea 

 

Clearly you don't understand the problem of coastal erosion!

 

These concrete barriers are designed to protect artificial structures like harbours and what not. They intensify existing problems on the natural shoreline, as this article rightly points out. Glad to see someone in Thailand is catching on, highlighting ill-informed beliefs in "progress".

 

 

 

Edited August 20, 20178 yr by Morakot

40 minutes ago, bheard said:

Don't be too dismissive. Mangroves are the way to go in tropical areas - cheap and effective. What he is saying makes sense. And he's given a good example to illustrate it.

 

In the some parts of the Northern hemisphere, proper coastal management includes the planting of marram grass encouraging the growth of thick rhizomes to reduce erosion

 

https://en.wikipedia.org/wiki/Ammophila_arenaria

1 hour ago, spidermike007 said:

is it possible to imagine the Thai government doing something progressive, preventive, visionary, or far reaching? Planting mangrove swamps?

They have known that mangroves should be planted on the coastline since 26 December 2004... when those areas that still had them suffered significantly (substantially significant ... like 70%) less damage when the tsunami rolled in...In those 13 years since I am personally unaware of the increased mangrove plantings... someone may be aware of a programme????

If only these experts knew if they simply wait long enough, they can be "shocked it happened so suddenly" just like it happens with the yearly floods

Build a breakwater 500 meters off the beach and use it as a landfill.  They should have it filled with rubbish and ready for a layer of topsoil before the first elections.  Samui will finally have a place to send theirs...

 

And yes, that's me taking the proverbial piss.

 

 

“The budget for a bamboo fence is only about Bt8 million per kilometre, and we could significantly reduce the cost to Bt2 million per kilometre if authorities let local people build their own defensive bamboo fences. We just need to repair the fences every three years,” Surajit said."

 

lol.... it just needs repairing every three years... this would be called maintenance.... which is what any barrier needs, but what it lacking here

 

if the Mississippi can be controlled, so can this.... and I'll warrant that this needs managing way back to release times (and volumes) of water at damns. If they reduce the speed that flood waters wash soil away, then they can reduce the amount of soil needing replacing 

16 minutes ago, farcanell said:

 

“The budget for a bamboo fence is only about Bt8 million per kilometre, and we could significantly reduce the cost to Bt2 million per kilometre if authorities let local people build their own defensive bamboo fences. We just need to repair the fences every three years,” Surajit said."

 

lol.... it just needs repairing every three years... this would be called maintenance.... which is what any barrier needs, but what it lacking here

 

if the Mississippi can be controlled, so can this.... and I'll warrant that this needs managing way back to release times (and volumes) of water at damns. If they reduce the speed that flood waters wash soil away, then they can reduce the amount of soil needing replacing 

 

Local thai are worldfamous for their yearly maintenance of things...Sure they will repair the bamboo fence every 3 years! 555

 

The latest technics to stop sanderosian is to build a "zandmotor"..at least that's the solution in Holland where they already have the worlds best dams and dykes.

 

For Bangkok they better hire some real experts, the Thai can't even keep their streetdrains clean and working.

 

Maybe this will give the Thai some inspiration about professional seabarriers...

 

Here some more inspiration...

Edited August 20, 20178 yr by Morakot