The economic expansion in the Western world has recently triggered an unprecedented energy rush to the coastal seas in the form of offshore windfarms (OWF). In the Dutch part of the North Sea most of these OWFs are currently located or planned in sandy areas, characterized by the presence of sand waves. These sand waves are several meters in height, hundreds of meters in wavelength and migrate with a speed of several meters per year. Our consortium (NIOZ and University of Twente and many end-users) recently showed that these large dynamic geomorphological features determine to a large extent the spatial organization of the biota and the sediment properties with possible consequences for biogeochemical functioning. Focusing on the upscaling of system effects due to offshore wind energy, we presume that changes induced by OWFs on the sediment ecosystem need to be framed in the context of how geomorphology, via its impact on hydrodynamics and sediment transport, affects benthic life and the biogeochemical functioning of the sediment.
In the footprint project, we will use a combination of fieldwork, and mechanistic modelling to investigate how OWFs affect the benthic ecosystem. We will perform dedicated field campaigns to quantify the impact of OWFs on sediment and oxygen dynamics, and to establish how OWFs alter the sediment geomorphology.
We will develop a new model repertoire that explicitly couples hydrodynamics, geomorphology, biogeochemistry and ecosystem descriptions. The coupled model will be tuned on the comprehensive data set acquired by the consortium and that is completed during the Footprint project. We will apply these model tools to run scenarios as a cost-effective strategy for optimizing OWF setup in order to stimulate blue growth together with our end-users.
