Geology for coastal management of Thailand
Coastal erosion is a main problem for Thailand on both Gulf of Thailand and Andaman Sea coasts which have a total length of 1,900 km. The severe eroded land occurred along the coast line of 200 km with average rate of 5 meters/year. The impact affected to public and government properties as well as socio-economic of the country. Moreover, the degradation of coastal resources such as beach, sand dune, mangrove swamp and lagoon including natural scenery need to be restoration and preservation for the benefit of the next generation.
Coastal evolution of Thailand
The coastal zone of Thailand formed during the last global sea transgression at 11,000-6,000 yrs. The regression phase caused the coastal plain prorogation until present time.
High-rise building close to the beach can cause the change of coastal morphology and interrupt sediment budget along the coast, example from Rayong, Eastern Thailand.
Damage of houses and coconut trees at NaKhorn-Sri Thammarat, Southern Thailand caused by tropical monsoon in 2003.
Local coastal structures can be a cause of coastal erosion in adjacent area.
Mangrove forest, natural coastal protection, was converted into shrimp farms and rapid erosion occurred.
CAUSES OF COASTAL EROSION IN THAILAND
1. Coastal development projects for tourism and large scale economic growth affected to natural coastal processes, Natural resources degradation and acetone of coastal environments.
2. The decreasing of upstream sediment supply due to dams and upland deterioration.
3. Climatic change during off-season shift monsoon and the dynamic of natural coastal processes.
4. Improper land-use activities along the coast and lack of planning for efficiency and potential of coastal resources exploitation.
5. Impact from local coastal protection structure can cause erosion in adjacent areas.
THE COASTAL GEOLOGOCAL INVESTIGATION
Several tools have been used for studying coastal change and monitoring coastal erosion in order to assess the impact and implement the mitigation plan which imply for the coastal zone management of the country as the final goal.
Systematic monitoring survey along the Andaman Sea coast, Southern region
Differential GPS setting and measurement of reference pole for monitoring of coastal erosion and its impact.
Geophysics survey in the sea for sea floor topography, oceanography and natural resources potential data.
Reference pole (white arrow) 5 m. From mean sea level in 1991.
In 1994, sea water inundated ref. pole And caused severely coastal erosion.
In 1995, a house collapse and The owner relocated.
Role of Department of Mineral Resources for coastal mitigation and management plans
1. Evaluate coastal erosion condition and classified the risk zone areas for mitigation measure.
2. Prevent and protect coastal risk areas by mean of mitigated action plan with environmental friendly protected structures both natural fences and engineering designs.
3. Restoration of coastal resources and imply proper tools for land-use planning.
4. Establish monitoring and evaluating system on coastal change condition as a tool for coastal zone managements such as monitoring network in local, regional and national scales. 5. Educate and encourage pubic awareness for systematic of coastal mitigation, natural resources restoration and management plans.