Far-Field and Long-Term Dispersion of Released Dredged Material
Type:
Presented during:
WODCON XX: "The Art of Dredging" - 2013, Brussels, Belgium
Authors:
Van Kessel T, van Maren DS
Abstract: Important questions with regard the release of dredged material in the natural environment are: 'How does it spread?' and 'Where does it deposit?’ and particularly near sensitive ecosystems: ‘What is the duration and magnitude of increased turbidity levels?'. Often the dispersion of individual plumes is considered, but on the long term the cumulative effect of a large number of individual plumes determines the impact. Resuspension from the seabed may become the dominant factor contributing to turbidity. The contribution of dredged material to the natural background turbidity depends on the type and amount of material added to the system relative to type and amount of fine sediment already present due to natural processes. We present examples of computations on the far-field and long-term dispersion of fines in the natural environment and their sensitivity to parameter settings such as settling velocity, critical shear stress for erosion and burial rate.
Keywords: dredged material, far-field, dispersion study