BALIKPAPAN — A research team from the Institut Teknologi Kalimantan (ITK) is investigating coastal hydrodynamics and sediment transport around the seawall at Nipah-Nipah Beach, Penajam Paser Utara Regency, East Kalimantan. The study aims to identify current and wave characteristics, as well as the potential for erosion and sediment deposition, to support the evaluation of sustainable coastal protection infrastructure.

The research, entitled “Hydrodynamic and Sediment Transport Modeling to Evaluate the Impact of the Seawall at Nipah-Nipah Beach, Penajam Paser Utara,” is funded by Institut Teknologi Kalimantan through the ITK Institute for Research and Community Service (LPPM) in 2026.

The research is led by Ir. Ahmad Azwar Mas’ud M., S.T., M.T., a lecturer in the Marine Engineering Study Program, Faculty of Sustainable Development at ITK, alongside Muhammad Iqra Prasetya, S.Si., M.Si., and Muhammad Abdul Ghofur Al Hakim, S.Kel., M.Si. The study also involves ITK students and is conducted in collaboration with the Coastal Dynamics and Coastal Engineering Laboratory of the National Research and Innovation Agency (BRIN).

Examining Coastal Hydrodynamics Around the Seawall

Nipah-Nipah Beach is a coastal area influenced by tides, currents, and ocean waves. The interaction of these natural processes affects sediment movement and changes in seabed conditions. The existing seawall, constructed using sheet piles as a coastal protection structure, may also influence sediment distribution in the surrounding area.

Interactions between currents, waves, and coastal protection structures can potentially cause erosion in certain locations and sediment deposition in others. Understanding hydrodynamic processes and seabed changes is therefore essential to supporting coastal monitoring, maintaining coastal structures, and evaluating the technical performance of coastal protection infrastructure in the future.

Integrating Field Surveys and Numerical Modeling

The research began with a field survey at Nipah-Nipah Beach in July 2026. The team conducted bathymetric measurements, coastal topographic surveys, tidal observations, current velocity measurements, and seabed sediment sampling. The collected data were then integrated with wave data to characterize the hydrodynamic conditions at the study site.

The team subsequently employed integrated numerical modeling to simulate current patterns, wave propagation, and sediment transport around the seawall. This approach enables the researchers to analyze current and sediment distribution patterns while identifying areas that may experience changes in seabed elevation.

To assess how accurately the simulations represented field conditions, the team compared the model results with observed tidal levels and current velocities. The evaluation indicated mean percentage errors of 11 percent for water surface elevation and 9.7 percent for current velocity.

Modeling Identifies Potential Erosion and Sediment Deposition

The modeling results indicate that current patterns around Nipah-Nipah Beach are influenced by tidal phases. During the flood tide, currents tend to flow northward, while during the ebb tide, the dominant current direction reverses southward.

The team also identified changes in wave characteristics as waves travel from offshore waters toward the coast. Waves exceeding 0.75 meters in height in offshore waters decrease to approximately 0.25–0.275 meters near the seawall. These changes are influenced by water depth and the configuration of the coastal area.

Although wave heights decrease, interactions between waves and currents continue to contribute to sediment movement along the seabed. The simulations indicate a general tendency for sediment transport toward the north, accompanied by varying patterns of potential erosion and deposition in several areas.

One of the study’s key findings is the identification of areas potentially experiencing a decrease in seabed elevation along the seaward side of the seawall. Based on a one-month simulation, the average decrease in seabed elevation along the seawall is estimated at approximately 0.10 meters, with a maximum localized decrease of around 1.62 meters in certain areas. Sediment deposition zones were also identified farther away from the seawall.

These findings indicate potential seabed changes based on numerical simulations rather than direct measurements of scour depth at the seawall foundation. Therefore, further field observations and studies are needed to verify actual seabed conditions and evaluate the structural stability of the seawall in greater detail.

Supporting Sustainable Coastal Infrastructure Management

The research findings are expected to provide preliminary information for identifying areas potentially affected by erosion and sediment deposition around coastal protection structures. This information may serve as a basis for monitoring seabed changes, planning maintenance activities, and conducting further studies on coastal infrastructure stability.

In addition to contributing to the advancement of coastal engineering, the research provides a learning opportunity based on real-world challenges in East Kalimantan’s coastal regions. Student involvement offers hands-on experience in hydro-oceanographic surveys, field data processing, and the application of numerical modeling techniques.

Collaboration with BRIN’s Coastal Dynamics and Coastal Engineering Laboratory also supports the research through technical assistance and access to numerical modeling facilities. This partnership forms part of broader efforts to strengthen research collaboration between higher education institutions and national research agencies.

The study also aligns with the Sustainable Development Goals (SDGs), particularly Goal 11 on Sustainable Cities and Communities and Goal 14 on Life Below Water.

Through this research, ITK continues to promote applied studies that advance scientific knowledge while providing a scientific basis for coastal management and the development of sustainable maritime infrastructure in East Kalimantan.