Morphological Evolution of Sand Spits in Thailand

Abstract A sand spit is a deposition of sediments built up and diverging from the coast. The spit can be beneficial or create problems. Understanding and being able to forecast its evolution is the key to maximizing its advantages and minimizing its drawbacks. Along the southern Gulf of Thailand, there are 3 major sand spits, being Laem Talumpuk spit, Laem Sui spit, and Laem Tachi spit. Each individual spit’s evolution was investigated by overlaying satellite images gathered from the U.S. Geological Survey and Google Earth. Five types of equations for their evolution were tested to determine the best-fitting relationships. Although it was found that different spit characteristics followed different types of expression, polynomial equations seemed to provide satisfactory coefficients of determination for all spits in the study. Each individual spit’s length, size, and orientation could be predicted by the derived relationships. Finally, proper spit managements such as dredging, community livelihood adaptation, economic development, and even tourism promotion can be planned.