Presentaties en artikelen
Presentaties
Equilibrium and stability of a double inlet system
Barrier island coasts are a common feature in many parts of the world. An example is the Wadden coast of The Netherlands, Germany and Denmark. These coasts consist of barrier islands separated by tidal inlets with at the landward side tidal basins.Characteristic for the Wadden Sea is that the tidal basins are not completely separated,but are connected via topographic highs allowing exchange of water between the basins. As a result the tidal inlets that connect the basins to the North Sea will interact. The focus in this thesis is on the effect of this interaction on the cross-sectional equilibrium and stability of tidal inlets that are part of a double inlet system. The knowledge gained in this study will help to develop rational management plans for this kind of system. In determining the equilibrium values and stability of cross-sectional areas of the inlets use is made of flow diagrams. A flow diagram consists of the equilibrium flow curves of each inlet and a flow field showing the adaptation of the inlet cross-sections after the system has been removed from equilibrium. Each intersection of the equilibrium flow curves represents a stable or unstable equilibrium. The equilibrium flow curve for each
inlet is the locus of the values of the cross-sectional areas for which the velocity
amplitude in the inlet equals the equilibrium velocity i.e. approximately 1 m/s according to ESCOFFIER [1940]. As a start the double inlet system is schematized as a basin connected to the ocean by two channels. The water surface area of the basin is assumed constant and water levels are assumed to fluctuate uniformly. On the seaward side a simple harmonic, semidiurnal tide is used to force the system. Analyzing the double inlet system under these conditions by means of the flow diagrams leads to the conclusion that a stable equilibrium of the two inlets does not exist. Ultimately only one inlet remains open and the other will close. This confirms the earlier conclusions of VAN DE KREEKE [1990] and BORSJE [2003] concerning the cross-sectional stability of multiple inlet systems.
Artikelen
Modelling the seasonal dynamics of SPM with a simple algorithm for the buffering of fines in a sandy seabed
This paper discusses the application of a simple algorithm for the buffering of fines in a sandy seabed. A second layer is introduced in which fines may be stored during calm weather and from which fines may be resuspended during storms. The algorithm is applied first in a one-dimensional vertical (1DV) point model at a location in the North Sea, Noordwijk 10, 10 km offshore. It is able to reproduce the observed temporal variability of suspended particulate matter satisfactorily. Apart from the second layer, also the applied first order erosion rate is an important element of the algorithm. This allows for an equilibrium sediment mass per unit area for any combination of bed shear stress climate and sediment supply. The classical Partheniades-Krone formulation with zeroth order erosion (i.e. an erosion rate that is independent from the sediment mass per unit area) does not have such equilibrium.
As a next step, the algorithm is incorporated into a 3D model for suspended particulate matter (SPM) transport in the Dutch coastal zone. It is demonstrated that the model is able to reproduce the observed spatial and temporal variability reasonably well. An essential feature of the 3D mud model is that it is sufficiently fast to compute equilibrium bed composition. This implies that the results are completely independent from the applied (uniform) initial conditions.
Finally, the mud model is applied to assess the impact of a large-scale release of fines in the Dutch coastal zone. The computed impact turns out to be very sensitive to the assumed buffer capacity of the seabed. However, information on transient system response (such as the dissipation of a sediment pulse in the system) from which the buffer capacity may be estimated is most often lacking. For the time being, estimates on the residence time of fines in the seabed and its mixing depth are derived from the literature. Additional field and laboratory test on the exchange mechanisms of fines between the water column and a sandy seabed are recommended.
Placing accuracy and stability of geocontainers
The distribution of macrozoobenthos in the Southern North Sea in relation to meso-scale bedforms
Observations of sand waves, megaripples, and hummocks in the Dutch coastal area and their relation to currents
and combined flow conditions
Processes controlling the dynamics of compound sand waves in the North Sea, Netherlands
Samen het NCP beter begrijpen
Acoustic mapping of shellfish habitatsin the western Wadden Sea (NL)
Acoustic survey of oysters in the Oosterschelde (NL)
Smart nourishment of ebb-tidal deltas (presentation at ICCE) (ppt)
Article in the Journal Geotechniek (png file)
Final report on the Deltaflume experiments regarding the stability of geocontainers
Journal
In Preparation
· Van Koningsveld, M., B. de Sonneville, E. Elias, L.C. van Rijn, Z.B. Wang, 2008. “Sediment budget analysis of the Dutch coastal system.” Journal of coastal research (in preparation)
· Van Koningsveld, M., J. Lescinsi, B. de Sonneville, 2008. “Analysis of nourishment effectiveness in the Dutch coastal system.” Journal of coastal engineering (in preparation)
Under Review
· Koster, L., J.A. Roelvink, D.J.R. Walstra, M. van Koningsveld, M.J.F. Stive, 2007. “Humps or Bars: Alongshore Nourishment Length as an Important Design Parameter.” Journal of coastal engineering (Under review)
· M. van der Wegen, Z.B. Wang, H.H.G. Savenije and J.A. Roelvink., 2007. Long-term morphodynamic evolution and energy dissipation in a tidal embayment. JGR Earth Surface Proc. (Under review)
· Stive, M.J.F., Cowell, P. and Nicholls, R.J., 2007. Impacts of global environmental change on coasts. Book Chapter International Association of Geomorphology
In Press
· Van Koningsveld, M.; Stive, M.J.F.; Van der Valk, L., Van der Weck, A.W. and Mulder, J.P.M., 2008. “Living with Sea Level Rise. A case study of the Netherlands.” Journal of Coastal Research (SURVAS special issue – in press)
· Willem M. Hartog, Lindino Benedet, Dirk-Jan R. Walstra, M. van Koningsveld, Marcel J.F. Stive, Charles W. Finkl. 2007. “Mechanisms that Influence the Performance of Beach Nourishment: A Case Study in Delray Beach, Florida, USA.” Journal of Coastal Research (in press)
· Baptist, M.J., J. van Dalfsen, A. Weber, S. Passchier, S. van Heteren, 2006. “The distribution of macrozoobenthos in the southern North Sea in relation to meso-scale bedforms.” Estuarine, Coastal and Shelf Science. (in press)
· Van der Wegen, M. and J.A. Roelvink, 2007. Long-term morphodynamic evolution of a tidal embayment using a 2 dimensional process based model.. Journal of Geophys. Res. (Accepted)
· Stive, M.J.F., Ranasinghe, R. and Cowell, P.J., 2007. Sea level rise and coastal erosion, Book Chapter Handbook of Coastal and Ocean Engineering
Published
· Davidson, M., Van Koningsveld, M., de Kruif, A., Rawson, J., Holman, R., Lamberti, A., Medina, R., Kroon, A., Aarninkhof, S., 2007. “The CoastView project: Developing video-derived Coastal State Indicators in support of coastal zone management.” Journal of Coastal Engineering 54(2007) 463-475
· Van Koningsveld, M., Davidson, M., Huntley, D., Medina, R., Aarninkhof, S., Jimenez, J., Ridgewell, J. De Kruif, A., 2007. “A critical review of the CoastView project: Recent and future devellopments in coastal management video systems.” Journal of Coastal Engineering 54(2007) 567-576
· Van Koningsveld, M.; J. Lescinski, 2007. "Decadal scale performance of coastal maintenance in the Netherlands" Shore and Beach Vol. 75 No. 1 (Winter 2007) 20 – 36
· Jonkman, S.N., Stive, M.J.F. and Vrijling, J.K., 2005. “New Orleans is a lesson to the Dutch”. Journal of Coastal Research, 21 (6), XI-XII
· Dijk, T.A.G.P. van, M.G. Kleinhans, 2005. “Processes controlling the dynamics of compound sand waves in the North Sea, Netherlands.” Journal of Geophysical Research (Earth Surface), 110, F04S10, doi:10.1029/2004JF000173.
· Passchier, S., M.G. Kleinhans, 2005. “Observations of megaripples and hummocks in the Dutch coastal area and their relation to currents and combined flow conditions.” Journal of Geophysical Research (Earth Surface), 110, F04S15, doi:10.1029/2004JF000215.
· Stive, M.J.F., 2004. How important is global warming for coastal erosion? Climatic Change 64 (1-2): 27-39
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