Beach systems of the central Netherlands coast: processes, morphology and structural impacts in a storm driven multi-bar system
In: Marine Geology. Elsevier: Amsterdam. ISSN 0025-3227; e-ISSN 1872-6151, more
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| Abstract |
The 124 km long central Netherlands coast consists of a sand barrier system fronted by beach and surf zone containing 2 to 3 bars. The beach and surf zone are the product of wind waves generated in the North Sea, interacting with the medium to fine shoreface sands, in a micro tidal environment. The inner bar is usually attached to the beach as a ridge and runnel cut by drains and rips, the second and third bars are highly rhythmic and are characterised respectively by transverse bars and rips and rhythmic to longshore bar and trough bar types. Structural impacts influence 48 km of shore with harbour moles inducing lower wave energy and shoreline progradation, a 4.5 km long dyke replaces part of the beach but apparently has had little impact on mesoscale bar dynamics, while 158 groynes in three fields have produced more intermediate, rip driven, surf zones. Natural beach processes however dominate the entire coast with the hierarchical bar morphology related to cross-shore wave breaking. The equilibrium beach concept of Wright et al. (1987) was used to empirically predict beach/bar type. The results explain both the hierarchy of bar type and the temporal variation in beach-bar type. Finally a multi-bar “beach model” for the coast is presented which builds upon the single bar model of Wright and Short (1984). |
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