Texel is one of the barrier Islands of the Wadden coastal system. To protect Texel against coastline retreatment due to coastal erosion in the north-west corner of the island (Eierland), a dam was built perpendicular to the shoreline in 1995 to interrupt the littoral drift . To predict the morphological development near the planned dam, the Dutch Ministry of Infrastructure and Environments has done some research using morphological prediction models at the time (1993). Directly after completion of the dam, it turned out that the physical development of the coastal region was not similar to the prediction models. (Note that the dam is located inside an ebb tidal delta.) Strong flow velocity - and sediment transport gradients make correct modelling of the situation considerably complex.
During a few weeks after completion of the dam, a relatively deep scour hole developed behind the dam tip and strong sedimentation occurred on downdrift side of the dam. Both were not expected. After these remarkable morphological observations, different parties have done research again to figure out the basic mistakes they made in the previous predicting models. Shortcomings of computational models were their main conclusions. In particular modelling of 3D flow-patters were rather complex.
In the last decades, the abilities of modelling software and computer power have increased enormously. With highly developed three-dimensional modelling software, the morphodynamics of Eierland is an interesting case again. During this study, the main focus will be on short term morphodynamics of Eierland. (Approximately the first five years after completion of the dam) Purpose of this thesis is to find out the responsible processes for the unexpected short term erosion- and sedimentation patterns around the Eierlandsedam.
Figure 1. Eierland before dam construction. Year: 1990
Figure 2. Eierland including the dam and clearly visible sediment accumulation around the dam. Year: 2011.
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