WAVE ENERGY SPECTRUM MODELING BASED ON TIDAL HEIGHT VARIATION IN RECLAMATION AREA OF JAKARTA BAY (CASE STUDY: TYPHOON HAGIBIS EVENT ON 2007)

• Main Author: Ardiansyah, Iqbal
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50277
• Institution: Institut Teknologi Bandung

Effect of tidal height variation on significant wave height (Hs) in reclamation area of Jakarta Bay has been simulated using Simulating Wave Nearshore (SWAN) model during Typhoon Hagibis event on 2007. The tidal variation that used for input in spectral wave model was obtained from Delft3D Flexible Mesh (FM) hydrodynamics model result, which has been simulated with the same domain model. Meanwhile, open boundary in Delft3D FM hydrodynamic model was inputted with tidal elevation and current velocity from South China Sea (SCS) model result. The SCS model has been simulated in Delft3D FLOW hydrodynamic model. The open boundary information aims to accommodate effect of the Typhoon Hagibis event that occurred in SCS. The spectral wave model is run on 15th October – 15th December 2007 using wind and bathymetry data as model input, also tidal elevation from Delft3D FM hydrodynamic model result. The 1/4° wind data obtained from Cross-Calibrated Multi-Platform (CCMP) and 1/600° bathymetry data derived from Indonesian Geospatial Information Agency (BIG). Meanwhile, the spectral wave parameter in open boundary values for the SWAN model was obtained from Ardiansyah (2019) research result. In this current study, it was found that the effect of the tidal variation on Hs is quite small. This is due to the tidal range in Jakarta Bay also small (<1 m). However, tidal influence is quite significant in shallow water areas. Maximum difference between Hs with and without tide (?Hs) occurred at Point 9 (Bekasi) on December 4, 2007, of 10.31 cm and -10.96 cm for the most positive and negative Hs, respectively. In addition, the tide also affects the evolution of wave spectrum such as frequency shifts and change in wave direction and spectrum energy density with the largest frequency shift occurring at Point 9 of 0.47 Hz. Meanwhile, lag correlation analysis showed that swell generated by the Typhoon Hagibis on peak phase (November 23, 2007) arrived in the Jakarta Bay after 11-days of travel time.