Validation of dBSea, Underwater Noise Prediction Software. Pile Driving Focus
نویسندگان
چکیده
This report aims to characterise the prediction error of the different noise modelling algorithms used by the underwater noise prediction software “dBSea”. Two shallow water pile driving scenarios are presented, and the software’s prediction is matched against the measured real world data. The results of the comparison show that while you can get good results with a simple model based on spherical and cylindrical spreading and information on frequency dependent attenuation, the more advanced “ray tracing” algorithm performs better still, and is more robust in accuracy. Also, the ray tracing has good consistency with the measurements at all ranges (380-5700 m -0.3 dB/km), while the simple model gets more erroneous with increased distance (+2 dB/km). Further two approaches, namely “normal modes” and “parabolic equation”, both perform markedly worse than ray tracing in the presented scenarios, underlining the need for caution when applying models to real world scenarios. It is therefore suggested that a specialist is consulted before application of noise propagation models, as some approaches can produce outright wrong results for specific scenarios. Such errors could lead to damage of the marine ecosystem and to legal action against the polluter. Also, for scenarios where there is strong disagreement between models, not explained by model weaknesses and strengths, field measurements should be used to validate results.
منابع مشابه
Measurement and Modelling of Underwater Noise from Pile Driving
Many coastal and offshore construction activities require the driving of piles into the seabed, either using impact or vibratory pile drivers. Impact pile driving produces an intense impulsive underwater noise that has been associated with fish deaths at very short range, whereas vibratory pile driving produces a lower level continuous noise. Because of the high sound levels involved, noise fro...
متن کاملAn efficient model for prediction of underwater noise due to pile driving at large ranges
Modelling the sound levels in the water column due to pile driving operations nearby and out to large distances from the pile is crucial in assessing the likely impact on marine life. Standard numerical techniques for modelling the sound radiation from mechanical structures such as the finite element (FE) and boundary element method are not well suited to predict the sound field efficiently at ...
متن کاملAssessing underwater noise levels during pile-driving at an offshore windfarm and its potential effects on marine mammals.
Marine renewable developments have raised concerns over impacts of underwater noise on marine species, particularly from pile-driving for wind turbines. Environmental assessments typically use generic sound propagation models, but empirical tests of these models are lacking. In 2006, two 5MW wind turbines were installed off NE Scotland. The turbines were in deep (>40m) water, 25km from the Mora...
متن کاملA computational method to predict and study underwater noise due to pile driving.
A hybrid modeling approach that uses the parabolic equation (PE) with an empirical source model is presented to study and predict the underwater noise due to pile driving in shallow, inhomogeneous environments over long propagation ranges. The empirical source model uses a phased point source array to simulate the time-dependent pile source. The pile source is coupled with a broadband applicati...
متن کامل