Wave Transformation and Propagation under Bathymetric Conditions Using CGWAVE on Kapota Island

Abstract

The coastal area of Kapota Island, Wakatobi Regency, is potentially vulnerable to coastal changes caused by wave activity, including coastal erosion and sedimentation. Waves propagating from offshore toward the coastal area undergo transformation due to changes in water depth and bathymetric conditions, which may affect wave height, direction, and propagation patterns before reaching the shoreline. This study aims to: (1) analyze wave height and period characteristics in the waters of Kapota Island using the CERC SPM 1984 method; and (2) analyze wave transformation and propagation patterns in relation to the bathymetric conditions of Kapota Island waters using the CGWAVE model operated through the Surface-water Modeling System (SMS) software. This study employs analytical and numerical modeling methods; wind, bathymetric, and other supporting oceanographic data were used as primary and secondary data. The analysis using the CERC SPM 1984 method indicates that the maximum significant wave heights from the North, West, and Northwest directions are 1.870 m, 0.582 m, and 0.643 m, respectively, with corresponding maximum significant deep-water wave periods of 5.802 s, 4.035 s, and 4.223 s. The CGWAVE simulation results indicate that the bathymetric conditions of Kapota Island waters influence wave transformation and propagation patterns, with maximum wave velocities from the North, West, and Northwest of 0.58 m/s, 0.56 m/s, and 0.55 m/s, respectively. The findings of this study are expected to provide information on wave transformation and propagation characteristics that can serve as a basis for coastal zone management and the planning of coastal protection structures on Kapota Island.