Creeping coastal erosion halted by 'blade' barriers that could see thousands of lost rai restored

New types of coastal protection called wave power disintegrating barriers were recently installed along part of the Samut Prakan coastline to slow erosion.

Since 1967, the province's coastline has lost more than 11,000 rai to the sea.

Assoc Professor Thanawat Jarusakulphong of Chulalong-korn University said the barriers - invented by his research team - could save another 37,000 rai from being claimed by the waves over the next 20 years. They could soon be installed along the entire length of the coast.

These protectors, officially called Khun Samut Jeen 05A2, are blades that cut through waves, reducing their impact on the shore.

They were named after Tambon Khun Samut Jeen in Phra Samut Chedi district, while the number signifies the year they were completed and the fact they are the second type.

They were first installed in June, covering a 250-metre stretch of the worst-hit area of the tambon.

Thanawat said initial results were satisfactory. The effect of the waves is absorbed and 30 centimetres of sediment have already accumulated. In the long term, the sediment will increase and serve as a permanent barrier along the coast.

Over the next two years, coastal barriers designed by the Thanawat team will be built to cover most of the 45 kilometres of Samut Prakan coast at a cost of Bt21 million.

When completed, lost land will have been reclaimed. It will be returned to those who used to occupy it, or sold at reasonable prices.

In the past several decades, villagers with homes in the tambon have been forced to move six or seven times because of erosion.

Village head Samorn Khengsamut hopes her former coastal property, now under sea water, will be reclaimed.

A large amount of sediment has already accumulated at the foot of the first 250-metre-long barrier, she said, adding that she has noticed the seas behind the barriers are much calmer these days.

"Villagers can now catch more shrimp in the calm waters," she added.

Samorn, 51, recalled that her family had relocated seven times in the past 20 years.

"My former school is now under water and can be seen far from the current shore. An ancient temple in this area is also now completely under water," she said.

Previously, rock dams and poles were built and rebuilt repeatedly by villagers to fight the tide, but they were unable to defeat nature for long.

"The government should support the coastal barriers project, so villagers do not have to retreat any further. Earlier, I was discouraged by some local politicians' lacklustre support for this scheme. Most of these guys prefer to sell construction materials used in building small embankment walls and dams, rather than having the new type of barrier," said Samorn.

Khun Samut Jeen is an ancient port area founded by Chinese immigrants centuries ago. It is the most vulnerable spot in the entire Phra Samut Chedi district.

Another resident, Sayant Poowilai, 65, said he had to build new home seven times over the past decades due to the receding shoreline.

"I will have no land left if the current home floods. If so, I and my two grandchildren will have to move to the temple," he said.

Phra Somnuek Atipanyo, abbot of nearby Wat Khun Samuttharawas, said its main hall had to be elevated a metre above sea level.

"Now, only a few homes near the temple are still around. More than 100 families have moved away," he said.

Malee Kawinpharikul, 55, another resident, called on the government to implement the barrier project quickly, while Samut Prakan Governor Anuwat Maythewiboolwut said coastal barriers were a good solution.

Thanawat said patents for the barriers were registered in Thailand and would be applied for overseas, too.

Due to the effects of global warming, the country's 2,667-kilometre coastline is at risk of erosion. He said if no action were taken to counter erosion, Suvarnabhumi Airport would be under water in 100 years.

The government should spend Bt5.4 billion to build coastal barriers along the entire Gulf of Thailand coast in Bangkok, Chachoengsao, Samut Sakhon and Samut Songkhram, he said.

When completed, the barriers could see more than 38,000 rai of land and mangrove forest in these provinces restored.

It could be designated state land and developed, Thanawat added.

Anan Paengnoy

 The Nation