biogeomorphology: interactions between benthos and sediment dynamics university of twente, enschede,...
TRANSCRIPT
Biogeomorphology: interactions between benthos and sediment dynamics
University of Twente, Enschede, The NetherlandsDeltares, Delft, The Netherlands
Bas Borsje
Introduction
• Bio-geomorphology: interaction between benthos, water and sand
• Studying bio-geomorphodynamics offshore is important from an:• Ecological perspective (conservation of biodiversity)• Economic perspective (utilization of the seabed)
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Biogeomorphological processes
• destabilising the top layer of the sediment by crawling• filtering the fine sediment out of the water collumn• stabilising the top layer of the sediment by covering • adding roughness to the bottom• redistributing the sediment
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Field observations
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Field observations
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Modelling
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Validation
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• Lower near bed velocity → Lower ripples (direct) → Deposition of fine sediment → Lower ripples (indirect)
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Biogeomorphological interactions
Discussion
• Biota are able to influence the shape of the seabed• The shape of the seabed is linked to the species habitat• Understanding the coupled system is important• Anthropogenic pressure will both influence sediment
dynamics and biota directly and indirectly• Windfarms• Nourishments• Dredging activities
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Conclusions
• Biological and physical processes show a dynamic interaction
• Importance to account for bio-geomorphological interactions offshore
Contact:[email protected]
Bas Borsje