3D Sound Propagation Modelling in Complex Underwater Environments

Noise is usually discussed in terms of what we hear in the air: traffic, aircraft, construction, and its effects on people. Underwater, however, sound travels further and faster, and many animals rely on it to communicate, find food, avoid predators and navigate. This means that underwater noise from human activities can disturb aquatic life over large areas.

Recent measurements in European rivers have shown that everyday transport activity alone, such as trains and road traffic on bridges or running in tunnels under rivers, and frequent sightseeing boats, can generate very high underwater sound pressure levels. In some cases, these exceed 170 dB re 1 µPa, dominated by low frequencies that many fish species are most sensitive to. Repeated exposure to such levels along a river could create acoustic barriers that make it harder for local and migratory species to move or use key habitats. Early results presented at an international conference on noise in aquatic life have highlighted these concerns, but current underwater sound propagation models cannot reliably predict how sound behaves in real, complex underwater environments.

This project will explore the use of three-dimensional finite element modelling (FEM), a powerful engineering numerical simulation tool, to predict how underwater noise from transport sources spreads in shallow, complex environments such as rivers, lakes, estuaries and ports. By comparing FEM predictions with field-collected underwater recordings, the project will test whether this approach can inform future noise maps for waterways and support better planning, impact assessment and protection of aquatic ecosystems.