This coastline zone is in monsoon trough and is constantly subjected to windstorm. The beach is exposed as the sea front has no island to blick off the coast. The beach is also quite-flat and gently sloped. The fine sand grains are thus easily carried by the windstorm, and pifing-u on the beach to form the Sand Dunes along the coast.
These Sand Dunes, which are clearly visible on the beach, are fond on the coast between Khoa Bangberd, Ban Nurnphu and Khoa Laem Yai, Ban Tham Thong in Patiew-district, Chumphon province.