Perpustakaan Digital ITB

This study presents a national-scale assessment of construction-phase underwater noise impacts from offshore wind turbine (OWT) monopile installation on marine mammals in Indonesian waters. Although offshore wind development is a key component of Indonesia’s energy transition, quantitative integration of acoustic environmental impacts remains limited in existing planning frameworks. This research addresses this gap by combining engineering-based acoustic modeling with spatial ecological analysis across techno?economically feasible offshore wind farm (OWF) candidate sites. Monopile geometric parameters—including diameter, pile length, penetration depth, and wall thickness—were derived using multiple linear regression based on a reference dataset of existing offshore wind projects. The resulting model identifies turbine capacity as the dominant design variable, producing representative monopile diameters of approximately 4.11–6.64?m for the 2.5?MW turbine class, with site-specific adjustments captured through secondary parameters. Underwater noise source levels were estimated using two complementary approaches: the Energy Conversion Factor (ECF) framework of Wood et?al. (2023) and the empirical scaling law of von?Pein et?al. (2022). The Wood model produces uniform and conservative Energy Source Levels (?209–211?dB re 1?µPa²·s), while the von?Pein model exhibits greater sensitivity to site-specific parameters, generating more variable Sound Exposure Levels. Transmission loss modeling indicates that Permanent Threshold Shift (PTS) impact ranges remain relatively limited, extending up to 430–614?m (Wood model) and 85–191?m (von?Pein model) depending on hearing group and hammer scenario. In contrast, Temporary Threshold Shift (TTS) zones extend significantly further, reaching 8–19?km (Wood model) and 2.6–6.0?km (von?Pein model). These results highlight the strong dependence of predicted impact extent on model selection. Spatial overlay analysis in QGIS reveals substantial overlap between acoustic impact zones and marine mammal habitats, particularly for Balaenopteridae, Delphinidae, and Physeteridae. The integrated risk classification framework—combining acoustic exposure, ecological vulnerability, and wave-based installation windows—identifies a clear west-to-east gradient, with low-risk zones concentrated in the Java Sea and higher-risk regions in the Banda Sea, Maluku, and offshore Papua. Seasonal analysis shows increased risk levels during August–October. The findings demonstrate that offshore wind development in Indonesia must incorporate both spatial and temporal considerations to minimize ecological impacts. The study provides a first-order, evidence-based framework for acoustic risk assessment and supports targeted mitigation measures including optimized installation timing, noise reduction technologies, and spatial planning strategies.