How can we assess the effect of measures to reduce underwater radiated noise from ship traffic in an efficient way? In a new publication, researchers from DEMASK work package 2 developed a model for a generic local shipping lane scenario to study the effects of mitigation measures in a computationally efficient way. This approach offers an efficient way to calculate the effectiveness of measures to reduce shipping noise before testing them in large-scale sound maps.
Animals in the North Sea are disturbed by underwater radiated noise from ship traffic. This noise pollution can be reduced by requiring ships to produce less underwater noise, for example by setting limits to the radiated noise level (RNL) of individual vessels or to ship speed.
Modelled shipping noise maps can be used to quantify the effects of selected noise reduction measures. However, calculating sound maps for large-scale sea regions over a relevant period, such as a month, requires substantial computational power and time. This makes it difficult to study many different noise management scenarios.
To address this, the researchers developed a model for a generic local shipping lane scenario. This model makes it possible to study the effects of mitigation measures in a computationally effective way and to identify the most promising options before applying them in large-scale sound maps.
The results show that the proposed speed limits studied in the paper lead to a median reduction of about 2 dB, while the proposed RNL limits lead to a median reduction of about 4 dB. In addition, the shipping lane model can be used to calculate the limit values needed to achieve a specified sound level reduction.
Read the paper here: https://link.springer.com/rwe/10.1007/978-3-031-94229-7_25-1