SEDIMENT TRANSPORT MODELLING
Sediment transport models are required to determine the fate of disturbed seabed sediments e.g. during dredging operations, disposal of dredged sediment, sediment excavations for pipeline/cable laying and other offshore structures.
DIVAST (Depth Integrated Velocities and Solute Transport) is a two-dimensional, depth-integrated time-variant model, which has been developed for estuarine and coastal modelling. DIVAST consists of a number of modules, which can be activated according to the requirements of a particular problem e.g. the hydrodynamic sediment transport module. The hydrodynamic model is capable of simulating tides, winds (wind induced stress and resulting currents) seabed friction, Coriolis force (responsible for surface slope) and discharge from rivers or outfalls. The sediment transport model uses the output from the hydrodynamic model to compute the dispersion of sediment in the water.
Sediment transport models take into account a number of factors, e.g. quantity of sediment, density of sediment, grain size, current speed and direction, water depth and method of sediment release.
Sediment transport models help to determine the impacts on the water column and the seabed.
EXAMPLES OF PROJECTS UNDERTAKEN BY AQUAFACT INCLUDE:
- Sediment transport model at a proposed dumpsite in the Shannon Estuary
- Sediment transport model in Inver Bay, Donegal