An integrated acoustic modeling infrastructure for underwater noise impact assessment

Abstract

When industrial activities such as underwater dredging or seismo-acoustic surveying are planned near ecologically sensitive areas, effective forecasting of the associated sound levels is often necessary to allow effective noise management planning and to satisfy permitting requirements. To this end a comprehensive software application, the Marine Operations Noise Model, was developed to enable the estimation of aggregate noise levels from complex operations involving numerous activities over extended regions. The softwares architecture includes a specially adapted Parabolic Equation propagation model, a database of field measured spectral source levels from a wide range of industrial vessels, a run module that coordinates modelling and summing of sound from multiple sources, and a GIS interface for the definition of operational layouts and the display of noise level contours on area maps. This application has been used in the planning and regulatory approval process for future pipeline and offshore platform installation activities to take place in the proximity of marine mammal habitats. Its accuracy in this context was validated through an extensive program of acoustic monitoring of similar activities taking place in a nearby location over the course of a prior construction season.