ADAPTATION OF A BOUSSINESQ WAVE MODEL FOR DUNE EROSION MODELING

Nils Droenen, Rolf Deigaard

Abstract


In the present paper we consider the adaptation of the Boussinesq wave model MIKE21 BW to the case of dune ero-sion. The process of dune front erosion and redistribution of the eroded dune material was described by two separate models. Erosion was modeled as an effect of direct impact from wave fronts on the dune front and subsequently slumping. Redistribution of the slumped material was modeled using a simple power law model connecting the depth integrated flow velocity with the local sediment transport. The paper presents three model tests. First the model was tested against Deltaflume experiment T01 showing a good overall agreement. Then the model was run for a number of numerical test cases: 1) Sensitivity to main parameters and 2) the effect of adding sand to the dune foot as a mean to protect the erosion.

Keywords


Dune erosion; morphological modeling; Boussinesq

References


Bagnold, R.A., 1966, An approach to the sediment transport problem from general physics. Prof. Paper, 422-1, U.S.G.S.

Deigaard, R., 1989, Mathematical modelling of waves in the surf zone, Progress Report No. 69, Inst. Hydrodynamics and Hydraulic Eng. (ISVA), Technical Univ. Denmark, pp. 47-59.

Drønen and Deigaard, 2011, A Model for Wave Induced Erosion of Sandy Barriers, Proceedings in RCEM, River, Coastal and Estuarine Morpholdynamics, Beijing, China.

Dette, H.H, Larson, M., Murphy, J., Newe J., Peters, K., Reniers, A., Steetzel, H., 2002, Appli-cation of prototype flume tests for beach nourishment assessment, Coastal Engineering, 47, pp. 137-177.http://dx.doi.org/10.1016/S0378-3839(02)00124-2

Erikson, L.H., Larson, M., Hanson, H., 2007, Laboratory investigations of beach scarp and dune recission due to notching and subsequent failure, Marine Geology, 245, pp. 1-19.http://dx.doi.org/10.1016/j.margeo.2007.04.006

Fisher, J.S., Overton, M.F., Chisholm, T, 1986, Field measurements of dune erosion. Proceed-ings of the 20th Coastal Engineering Conference, ASCE, pp. 1107-1115.

Fredsøe, J, Deigaard, R, 1992, Mechanics of Coastal Sediment Transport, Advanced Series on Ocean Engineering – Volume 3, World Scientific, Singapore, 369pp.

Fuhrman, D.R., Madsen, P.A., 2008, Simulation of nonlinear wave run-up with a high order Boussinesq model, Coastal Engineering, 55, pp. 139-154.http://dx.doi.org/10.1016/j.coastaleng.2007.09.006

Hubbard, M., Dodd, N., 2002, A 2D numerical model for wave run-up and overtopping, Coastal Engineering, 47, pp. 1-26.http://dx.doi.org/10.1016/S0378-3839(02)00094-7

Hughes, S.A., Nadal N.C., 2009, Laboratory study of combined wave overtopping and storm surge overflow of levee, Coastal Engineering, 56, pp. 244-259.http://dx.doi.org/10.1016/j.coastaleng.2008.09.005

Kobayashi, N., Farhadzadeh, A., Melby, J., Johnson, B., Gravens, M., 2010, Wave overtopping of Levees and Overwash of Dunes, Journal of Coastal Research, 26, 5, pp. 888-900http://dx.doi.org/10.2112/JCOASTRES-D-09-00034.1

Lynnett, P.J., Melby J.A., Kim, D., 2010, An application of Boussinsq modeling of Hurricane wave overtopping and inundation, Ocean Engineering, 37, pp- 135-153.

Madsen, P.A., Sørensen, O.R., Schäffer, H.A., 1997, Surf zone dynamics simulated by a Bous-sinesq type model, Part I: Model description and cross-shore motion of regular waves, Coastal Engineering, 33, pp. 155-176.

MIKE21 STP, 2012, MIKE21 Sediment Transport Model, Scientific Documentation, DHI, Denmark.

Nishi, R., Kraus, N.C., 1996, Mechanism and calculation of sand dune erosion by storms. Pro-ceedings of the 25th Coastal Engineering Conference, ASCE, pp. 2325-2339.

Overton, M.F., Fisher, J.S., 1988, Laboratory investigation of dune erosion. Journal of Water-way, Port, Coastal and Ocean Engineering 114 (3), pp. 367-373.http://dx.doi.org/10.1061/(ASCE)0733-950X(1988)114:3(367)

Pontillo, M., Schmocker, L., Hager, W.H., 2010, 1D numerical evaluation of dike erosion due to overtopping, Journal of Hydraulic Research, Vol. 48, pp. 573-582.http://dx.doi.org/10.1080/00221686.2010.507005

Roelvink D., Reniers A., van Dongeren A., de Vries J.T., McCall R., Lescinski J., 2009, Model-ing impact on beaches, dunes and barrier islands, Coastal Engineering, 53, pp. 1133-1152.http://dx.doi.org/10.1016/j.coastaleng.2009.08.006

Schäffer, H.A., Madsen, P.A. and Deigaard, R., 1993, A Boussinesq model for waves breaking in shallow water, Coastal Engineering, Vol. 20 (3-4), pp. 185-202.http://dx.doi.org/10.1016/0378-3839(93)90001-O

Tuan, T.Q., Oumeraci, H., 2010, A numerical model of wave overtopping on seadikes, Coastal Engineering, 57, pp. 757-772.http://dx.doi.org/10.1016/j.coastaleng.2010.04.007

van Gent, M.R.A., van Thiel de Vries, J.S.M., Coeveld, E.M., de Vroeg, J.H., van de Graaf, J., 2008, Large Scale dune erosion tests to study the influence of wave groups, Coastal Engi-neering, 55, pp. 1041-1051.http://dx.doi.org/10.1016/j.coastaleng.2008.04.003


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