Author(s): Bram Van Prooijen; Thijs Van Kessel; Mathijs Van Ledden
Linked Author(s):
Keywords: Fine sediment; Water-bed exchange; Coastal zone the Netherlands
Abstract: The presence of fine sediment (defined as sediment with a diameter smaller than 63um) in the coastal zone is of major importance for the light climate in the seawater, therefore on the primary production and on its turn for the ecological health of the area. Proper modelling of the concentration of fine sediment is therefore of utmost importance for many environmental impact assessments. This study is part of the EIA for the sand mining for the extension of Port of Rotterdam, the Netherlands: Maasvlakte 2. For this extension 6 Mtons of fines are overflown for the mining of 300 Mtons of sand, during a period of approximately 6 years. In this paper a formulation is presented for modelling the burial of fines in a sandy bed and the erosion of fines from this bed. The bed is split up into a quickly responding top layer and a slowly responding lower layer. A normal advection diffusion equation is used for the horizontal transport of sediments in the water. In combination with the tidal and wind forcing, the concentration can be simulated on tidal scale (days), neap-spring tide scale (weeks), seasonal scale (months) and the storm events. The model is calibrated and validated for the coastal zone of the Netherlands. The calibration with the point measurement at Noordwijk 10 shows the good resemblance on above mentioned timescales. Validation with the spatial pattern of the yearly averaged concentration is also reasonably good. Despite this good resemblance, the model is still fairly empirical, leaving room for further development.
Year: 2007