Waves Induce Sediment Transport at Coastal Region of Timbulsloko Demak

Abstract

Waves have variation of length and period. This influenced by seasonal variation. Impacts of seasonal variation related to wave is playing important roles in sediment transport mechanism and coastal changes. This condition not only treats coastal area but also decreases economic capacity of community. This research aim to determine different seasonal based on Indonesia Northwest-Northeast monsoon and Southeast-Southwest monsoon and theirs relation to sediment transport. Area of study is suffered by 938.73 H of abrasion. Conducted by CERC methods, transforming BMKG Ahmad Yani wind database (2005-2015) into wave’s data of seasonal variation and using field measurement recorded by ADCP. Definitely, maximum speed of wind is reached at 23 knots from December to February, wind direction predominantly from North West direction. Range of significant Wave Height (Hs) all season is 24.66-30.32 cm and Significant Wave period (Ts) count at 3.64-3.78 sec. Net of sediment volume annual 72,353.40 m3 year -1 and sediment movement pattern is forwarding from west to east direction. Correlation between breaking waves and sediment transport is linier.