Transforming Traditional Ways of Modelling Sediment Spill

In order to obtain approval from the authorities to undertake dredging activities it is usually a requirement to predict the expected sediment spill and assess potential consequences for the environment.

Today, this work is time consuming, costly and relies on highly skilled modelling experts. DHI’s new cloud-based service is about to completely transform modelling of sediment spill in marine environments.

In fact, the service can be operated by non-modelers through a web browser, said DHI.

Impacts can be modeled up-front for screening and impact assessment required for consenting, or one to six days forecast for planning and proactive management of spill impacts. The sediment transport and potential shading effect on bottom vegetation are modeled based on user input through a few simple steps including dredger position, sediment type, time period as well as water movement – based on DHI’s hydrodynamic models.

In the first planning or proposal phase, the cloud-based solution can significantly reduce time and cost required for screening of potential impacts on sensitive habitats or species. This also means that it is possible to change dredging plans and quickly update spill calculations.

Later in the EIA phase, a high-resolution model can be used to run alternative scenarios and to plan the most environmentally safe and efficient dredging.

In the construction phase, the model can run in forecast mode and allow adaptive and proactive spill control supporting optimization of the operation while meeting requirements for sediment spill thresholds set up to protection of sensitive habitats, cooling water intake or aquaculture sites.

The proactive modelling for dredging operations is being developed and tested in France during the Brest port development project (property of The Regional Council Of Brittany) together with DEME.

The scope of the works executed by DEME include the deepening of the access channel, the existing and new berths, as well as the construction of a berthing pocket for the new quay wall. By being able to better forecast dredged plumes, the contractor can be more confident that work will not need to be unexpectedly stopped or re-located due to unanticipated risks to the environment.

The new service is also capable of providing regulators with additional re-assurance that the best management tools available are being applied to projects.