title: Estimating source terms for far field dredge plume modelling.
abstract: Far field modelling of dredging induced suspended sediment plumes is important while assessing the environmental aspects of dredging. Realistic estimation of source terms, that define the suspended sediment input for far field dredge plume modelling, is key to any assessment. This paper describes a generic method for source term estimation as it is used in practice in the dredging industry. It is based on soil characteristics and dredge production figures, combined with empirically derived, equipment and condition specific 'source term fractions'. A source term fraction relates the suspended fine sediment that is available for dispersion, to the amount of fine sediment that is present in the soil and the way it is dredged. The use of source term fractions helps to circumvent modelling of complicated near field processes, at least initially, enabling quick assessments. When further detail is required and extra information is available, the applicability of the source term fractions can/should be evaluated by characterisation monitoring and/or near field modelling. An example of a fictitious yet realistic dredging project demonstrates how two different work methods can trigger two distinctly different types of stress to the environmental system in terms of sediment concentration and duration.
authors.affiliation: Van Oord Dredging and Marine Contractors B.V., P.O. Box 8574, 3009 AN Rotterdam, The Netherlands.
authors.forename: Johannes
authors.initials: J
authors.lastname: Becker
authors.affiliation: Van Oord Dredging and Marine Contractors B.V., P.O. Box 8574, 3009 AN Rotterdam, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: van Eekelen
authors.affiliation: Van Oord Dredging and Marine Contractors B.V., P.O. Box 8574, 3009 AN Rotterdam, The Netherlands.
authors.forename: Joost
authors.initials: J
authors.lastname: van Wiechen
authors.affiliation: Van Oord Dredging and Marine Contractors B.V., P.O. Box 8574, 3009 AN Rotterdam, The Netherlands.
authors.forename: William
authors.initials: W
authors.lastname: de Lange
authors.affiliation: Van Oord Dredging and Marine Contractors B.V., P.O. Box 8574, 3009 AN Rotterdam, The Netherlands.
authors.forename: Thijs
authors.initials: T
authors.lastname: Damsma
authors.affiliation: Van Oord Dredging and Marine Contractors B.V., P.O. Box 8574, 3009 AN Rotterdam, The Netherlands.
authors.forename: Tijmen
authors.initials: T
authors.lastname: Smolders
authors.affiliation: Van Oord Dredging and Marine Contractors B.V., P.O. Box 8574, 3009 AN Rotterdam, The Netherlands; Delft University of Technology, Faculty of Civil Engineering and Geosciences, P.O. Box 5048, 2600 GA Delft, The Netherlands. Electronic address: m.vankoningsveld@tudelft.nl.
authors.forename: Mark
authors.initials: M
authors.lastname: van Koningsveld
mesh_terms: D004058:Diffusion; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments; D057446:Hydrodynamics; D008962:Models, Theoretical; D014872:Water Movements
keywords: Dredging; Environmental impact assessment; Modelling; Plumes; Source term