VOP II- 1.1 Knowing the nearshore bathymetry : A data assimilation technique using Argus video and Delft3D

In this study, a state-of-the-art version of SBM-2DH is applied to update sub-tidal beach bathymetry through assimilation of video-observed and model-predicted patterns of wave dissipation and intertidal beach bathymetry. The position of the shoreline is mapped at different moments during the tidal cycle, using the intertidal Beach mapper by Aarninkhof (2003). From these shorelines, the intertidal beach bathymetry is constructed, which will serve as an assimilation source for the SBM-2DH model. The computed shoreline will be nudged towards the observed shoreline. The objectives of this study are: 1. To improve the SBM-2DH model by reformulating the assimilation method such that (1) assimilation sources other than dissipation can be included in the model and (2) the number of calibration coefficients is reduced. A gradient-method (Taylor) is implemented in the assimilation method that enables input of several assimilation sources and that contains less calibration coefficients than the former assimilation method; 2. To apply the model to a Dutch testcase to validate model performance compared to the model with the former assimilation method. For the validation we have used the same simulation period as used in Wijnberg et al. (2004) to be able to make a fair comparison.