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‘Hard’ erosion projects hit by wave of dissent

Mar 21. 2016
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By Pratch Rujivanarom
The Nation

Scientist warns of knockon effects as govt plans new seawall barriers

MORE than Bt300 million has been allocated for 10 new coastal erosion protection projects in the 2016 fiscal year budget, the Marine Department has disclosed.

However, a marine scientist warns that money spent on “hard” erosion protection projects will be counterproductive because they will cause more erosion of nearby shorelines, degrading both the ecology and beauty of the beaches.

Last winter proved to be another destructive season for the shoreline in the southern provinces. During the storm season, huge waves hit the coastline from Phetchaburi to Narathiwat in the South. In Nakhon Si Thammarat province alone, about 500 rai (80 hectares) were submerged, forcing more than 100 people from their land.

Wanchai Bootthongdee, the Marine Department’s Engineering Bureau director, said the department – which is tasked with implementing the plans of an integrative sub-committee tackling coastal erosion – had been granted Bt210 million this year earmarked for five coastal erosion protection projects, while Bt317.98 million was proposed for next year’s projects.

“Thailand’s coastline is about 3,100 kilometres long, and around 650km of the shore is facing coastal erosion problem; 160km is severely eroding, 400km encounters moderate problems and 80km is starting to have a problem or is on the watchlist,” Wanchai said.

“We are applying many forms of coastal erosion protection structures such as revetments, seawalls, groins and jetties, and soft measures such as refilling sand, according to the nature and environment of specific areas.”

He gave the example of beaches that are tourist destinations, where the department usually avoids building large concrete structures that would ruin the beauty of the beaches. But in other areas where problems are more serious, hard structures that withstand the waves are chosen.

However, Sakanan Plathong, a marine scientist from Prince of Songkhla University, said hard structures built on sandy beaches did not help coastal erosion, but instead caused problems for the nearby shoreline.

“As I researched coastal erosion on every beach in Thailand, I emphasise that shore erosion was mostly caused by the construction of hard structures encroaching into the sea,” Sakanan said.

“At many sites I visited, the erosion was caused by large concrete structures such as jetties, which disrupt the current and sediment movement resulting in erosion at nearby beaches.”

He said building hard structures to protect eroding shores would not make the situation better because it would alter wave patterns and affect nearby unprotected shores.

“When we protect one site with a hard structure, another site will be destroyed, so we have to build another coastal protection structure, and the entire beach will be destroyed like dominoes. Moreover, hard structures likes seawalls will change the geography of the shore, deepening the tidal area and causing higher and more destructive waves,” he said.

Responding to a question about how to stop the cycle, Sakanan replied that there were still many beautiful beaches that must be protected, but the first priority should be to refrain from building concrete structures that encroached on the shoreline.

“The beach can repair itself naturally, so all we have to do is to wait until nature refills the sand and do not interrupt this natural mechanism,” he said.

“For eroding areas affected by nearby hard structures, I suggest that we have to let some areas with low importance be swallowed by the sea to restore the balance and protect the next areas. Some of hard erosion protection structures should be removed to let nature work.”

On the level of policy-making, he said he would like the Marine and Coastal Resources Department to lead coastal erosion prevention efforts because staff there had a better understanding of the nature of the ocean.


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