Fight against coastal erosion: bamboo vs. concrete

Rows of bamboo poles have proved to be a more effective defence against coastal erosion than concrete barriers in muddy areas, but sandy areas pose a different, possibly insurmountable, problem.

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The reclaimed mud land along the shore of Samut Sakhon. Villagers have built rows of bamboo poles on the shoreline to prevent coastal erosion. (Photos by Paritta Wangkiat)

Fight against coastal erosion: bamboo vs. concrete

Paritta Wangkiat

For years, villagers in Samut Sakhon's tambon Khok Kham have watched the shoreline erode, not only damaging coastal marine life, but also encroaching on their homes and schools, forcing them to relocate to inner land.

Authorities tried using rocks and building concrete structures on the shore to prevent further damage.

But no one knew how to reclaim the five to 10 metres of muddy land that disappear from the shoreline every year.

It wasn't until 2003 that a group of villagers launched their own erosion prevention project by putting up rows of bamboo poles on the shoreline.

The bamboo sticks act as wavebreaking barriers while also allowing sediment to be stored behind them.

The locals learned the technique from mussel growers after they saw how sediment accumulated at bamboo poles placed in the sea to grow mussels.

"We learned that coastal mud is important for our livelihood, as much as it is for marine animals. So we began to try to get it back," said villager Worachart Janthong.

Within five years, about 100 rai of the mud land which had disappeared had re-emerged at a depth of one metre, said Mr Worachart.

Villagers planted mangrove trees on the reclaimed mud land to replace the decaying bamboo poles. Some marine life, including four species of mudskippers, reappeared, he said.

The locals planned to expand the mangrove forest, hoping to revive marine animals, the source of their food security, and prevent further erosion.

But the eroded coastline in Samut Sakhon is only a small part of the problem facing the country.

According to the Department of Marine and Coastal Resources (DMCR), Thailand has 3,148 kilometres of shoreline.

Of this, 830km – 730km in the Gulf of Thailand and 100km in Andaman coast – is being eroded. Eroded shorelines, from Samut Sakhon to Chachoengsao province, are at a critical point.

In most cases, authorities built concrete walls, offshore breakwater sea walls, revetments (sloping structures that absorb the energy of incoming water) or jetties to prevent erosion. However, some academics said these solutions led to even worse erosion.

In a recent case in Songkhla province, a shoreline erosion prevention project by the governor, using sand filling and large concrete groynes along Samila-Chalatad beach, was largely opposed by locals.

They said the project would worsen erosion and damage fishing prospects at the site.

Construction was halted after the Songkhla Administrative Court inspected the site last week.

The governor agreed to suspend the project until the court hands down a ruling. Locals, officials, and environmental experts will meet for talks on Wednesday.

Sakanan Plathong, lecturer at the Biology Department, Faculty of Science, at Prince of Songkla University, said concrete structures would not be a good solution as the erosion would simply move to a nearby spot away from the structures.

Mr Sakanan said the South's sandy coastline differed from the muddy one of Samut Sakhon, and that it would not be possible to use the Samut Sakhon villagers' bamboo pole technique there.

Erosion in the South is a battle that can't be won, he said.

You can read the full story here: http://www.bangkokpost.com/news/general/675060/fight-against-coastal-erosion

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