Detached Hexareef Breakwater Configuration Design to Reduce the Effect of Ocean Waves at Eco-Resort Area Raja Ampat

Abstract:

The Eco-Resort area at Raja Ampat is frequently impacted by extreme waves, particularly during the west monsoon, increasing the risk of abrasion and damage to ecosystems and infrastructure. A detached hexareef breakwater configuration was designed to reduce wave height while maintaining coastal aesthetics, as the site is an eco-friendly tourism area. The data used included tidal observations, bathymetry and topography surveys, wind and wave data, and hexareef formation data. The configuration was designed based on the beach response index, leading to periodic tombolo formation. Four configuration alternatives were developed based on freeboard (f) values under the HWS (Highest Water Springs) condition. Numerical modeling using Delft3D-WAVE assessed wave reduction effectiveness for each alternative. Results showed wave reductions for two significant wind and wave directions - North and Northwest - as follows: 24% and 33% for Alternative 1 (f = -1.018 m), 46% and 55% for Alternative 2 (f = -0.518 m), 66% and 71% for Alternative 3 (f = -0.218 m), and 72% and 77% for Alternative 4 (f = -0.018 m). Alternative 3 was chosen because its performance was only 6% lower than Alternative 4 (the most effective); however, it has a submergence value that is more suitable for maintaining coastal aesthetics.

• Periodical: Engineering Headway (Volume 27)
• Pages: 610-627
• DOI: https://doi.org/10.4028/p-PX6uSE
• Online since: October 2025
• Authors: Achmad Ridwan Abdullah*, Bambang Kun Cahyono, Haryo Dwito Armono
• Keywords: Coastal Aesthetics, Detached Hexareef Breakwater, Extreme Waves, Numerical Modeling, Waves Reduction

References

[1] L. H. Napitupulu, "Penelitian Gelombang Transmisi pada Terumbu Buatan dengan Bentuk Hexagonal (Hexagonal Reef) dengan Pengaruh Konfigurasi Horizontal," Departemen Teknik Kelautan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember, (2018).

DOI: 10.24089/j.sisfo.2014.03.015

[2] R. Akhwady, Mukhtasor, H. D. Armono, and M. Musta'in, "Pengaruh Beda Porositas Terumbu Buatan Tipe Silinder Berongga (Bottle Reef TM) sebagai Submerged Breakwater terhadap Kinerja Peredaman Gelombang," J. Ilmu Kelaut., vol. 17, no. 2, (2012), p.74–80.

[3] Badan Nasional Penanggulangan Bencana, RBI (RISIKO BENCANA INDONESIA) "Memahami Risiko Sistemik di Indonesia." (2023). [Online]. Available: https://inarisk.bnpb.go.id/BUKU-RBI-2022/mobile/index.html#p=10

DOI: 10.31227/osf.io/q83ct

[4] K. Triana and A. J. Wahyudi, "Sea Level Rise in Indonesia : The Drivers and the Combined Impacts from Land Subsidence ASEAN Journal on Science & Technology for Development Sea Level Rise in Indonesia : The Drivers and the Combined Impacts from Land Subsidence," ASEAN J. Sci. Technol. Dev., vol. 37, no. 3, p.115–121, (2021).

DOI: 10.29037/ajstd.627

[5] CERC, Shore Protection Manual US Army, vol. 1, no. 4th ed., Vol 2. Vicksburg, Mississippi, (1984).

[6] Ghifari, "Studi Eksperimen Refleksi Gelombang pada Terumbu Buatan Hexagonal dengan Pengaruh Konfigurasi Gap Secara Horizontal," Departemen Teknik Kelautan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember, (2018).

DOI: 10.24089/j.sisfo.2014.03.015

[7] H. D. Armono, "A Two Dimensional Hydrodynamic Model in the Vicinity of Articial Reefs," in Paper presented for PIT XXI, Denpasar, (2004).

[8] A. Winarto, "Pengaruh Konfigurasi Terumbu Buatan Bentuk Hexagonal pada Transmisi Gelombang," Departemen Teknik Kelautan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember, (2017).

DOI: 10.32315/sem.1.c053

[9] I. Z. Abrori, H. D. Armono, and M. Zikra, "Pengaruh Freeboard Terumbu Karang Buatan Bentuk Silinder Berongga Sebagai Breakwater Terbenam Dalam Mereduksi Gelombang," in Seminar Nasional Aplikasi Teknologi Prasarana Wilayah, Surabaya, (2009).

[10] V. Venugopal, R. Nemalidinne, and A. Vögler, "Numerical modelling of wave energy resources and assessment of wave energy extraction by large scale wave farms," Ocean Coast. Manag., vol. 147, p.37–48, (2017).

DOI: 10.1016/j.ocecoaman.2017.03.012

[11] Deltares, Delft3D-WAVE User's Manual: Simulation of Short-crested Waves with SWAN, 4.05. Delft, Netherlands: Deltares, Boussinesqweg 1, (2024).

[12] A. A. Yuliamangesti, "Evaluasi Kinerja Bangunan Pemecah Gelombang (Breakwater) di Pantai Puger Jember," (2017).

[13] M. G. Indra and M. Inri, "Analisis Pasang Surut Menggunakan Metode Least Square di Wilayah Perairan Muara Sungai Poso," JIPAD J. Infrastructure, Planning, Des., vol. 1, no. October, p.1–8, (2021).

DOI: 10.35508/fisa.v4i1.1428

[14] International Hydrographic Organization, International Hydrographic Organization Standards for Hydrographic Surveys, 6.1.0., no. S-44. (2022).

[15] B. Triatmodjo, Teknik Pantai. Yogyakarta, (1999).

[16] H. D. Armono, A. Manurung, and Sujantoko, "Model Gelombang di sekitar Hexagonal Artificial Reef sebagai Submerged Breakwater Menggunakan DUALSPHYSICS," Rekayasa J. Sci. Technol., vol. 15, no. 1, p.36–45, (2022).

DOI: 10.21107/rekayasa.v15i1.13484

[17] U.S. Army Corps of Engineers, "Shore Protection Manual Volume II Coastal Engineering Research Center," Dep. ARMY Waters. Exp. Stn., Corps Eng. Coast. Eng. Res. Cent., vol. II, p. 652p, (1984).

DOI: 10.5962/bhl.title.47829

[18] K.K. Marpaung, "Studi Penelitian Transmisi Gelombang pada Terumbu Buatan Hexagonal (Hexareef) dengan Pengaruh Konfigurasi Horizontal dengan Gap," Departemen Teknik Kelautan, Fakultas Teknologi Kelautan, Institut Teknologi Sepuluh Nopember, (2018).

DOI: 10.24089/j.sisfo.2014.03.015

[19] H. Wirayuhanto and H. D. Armono, "Pengaruh Konfigurasi Terumbu Buatan Bentuk Heksagonal pada Kemampuan Peredaman Gelombang," J. Sci. Technol., vol. 14, no. 1, p.106–113, (2021).

DOI: 10.21107/rekayasa.v14i1.10042