CROSS-SHORE SEDIMENT TRANSPORTS ON A CUT PROFILE FOR LARGE SCALE LAND RECLAMATIONS

Martijn Onderwater, Dano Roelvink, Jan ver de Graaff

Abstract


When building a large scale land reclamation, the safest way is to shift the existing profile over the required distance of the reclamation project, up to a depth of say 20 m. This way the profile in cross-shore direction does not change and therefore also cross-shore sediment transports will be the same as before the land reclamation was made. A large disadvantage however is that a very large amount of material is needed for realising the reclamation. This makes the reclamation very costly. To reduce the amount of material a cut profile can be applied. Above a certain depth (say CD -8 m) the cross-shore profile will be the same as the existing profile, but below this depth a relatively steep profile (say 1:50) is constructed. By doing this, material saving up to 40% can be achieved. A disadvantage of this cut profile is that a relatively steep profile has been made, which will effect the sediment transports. In this study the effect of a cut profile are investigated by using the numerical model UNIBEST-TC of DELFT HYDRAULICS for the computation of wave energy dissipation and cross-shore sediment transports. As an example the 'Plan Waterman', a plan for a land reclamation between Hook of Holland and Scheveningen, is used in this study. Various different cut profiles have been studied and it is found that especially relatively large waves, which break at the edge of the cut-off, have large influence on the cross-shore sediment transports. It is concluded, that the cut-off should at least be applied at CD-I2 m if large changes in the coastal system are not desired.

Keywords


large scale reclamation; reclamation; crossshore transport; sediment transport

Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.