Transpormasi gelombang di sepanjang pantai delta Sungan Jeneberang, Makassar (Wave transformation in the coast of delta Jeneberang River, Makassar)

Abstract

A study on wave transformation has been conducted in the coast of delta of Jeneberang River, Makassar. The wave heights and periods at deep water offshore of the coast are predicted using wind data recorded at Potere Stasiun, Makassar in 1990-2008. Wave transformation as these deep water waves propagated toward the coast are analized by considereing the effect of shoaling and refraction to determine changes of wave patterns (wave directions and heights) and the breaking of the waves near the coast. Results show that offshore wave heights and periods vary between 0.26 to 2.78 m and 3.06 to 7.26 seconds, respectively. Higher waves height accured generally in December to February (northwest Monsoon) than in the June to August (southeast Monsoon). This study indicated that when the waves propagate from deep water to the shore, wave height decreased as the water depth shallower but as the depth continue decreases nerby the coast the wave height gradually increased until it reaches maximum height then the waves break. After wave breaking, wave height is reduced drastically to zero at the shoreline. The results showed that waves tended to be converge at convex-shaped coastline (around the river mouth), whereas at concave-shaped coastlines waves tended to be divergent.