AN ANALYTICAL MODEL TO PREDICT DUNE AND CLIFF NOTCHING DUE TO WAVE IMPACT

Magnus Per Larson, Tsuguo Sunamura, Li Erikson, Atilla Bayram, Hans Hanson

Abstract


A model was developed to calculate the evolution of a notch in a dune or cliff due to wave impact. Analytical solutions were derived to the model for schematized conditions regarding forcing and dune/cliff properties. Comparisons were made with laboratory experiments where the time evolution of the notch was measured. Values of the transport coefficients in the analytical solutions were determined by least-square fitting the solutions to the laboratory data. Some of these coefficients could be related to the ratio between parameters describing the forcing and the dune/cliff strength. The evolution of the dune notch displayed a linear behavior at short times, whereas the cliff notch showed a more complex response for cases where a feedback between the notch and a beach formed seaward of the cliff occurred.

Keywords


erosion; cliff erosion; notching; analytical model; laboratory experiments

References


Erikson, L. and Hanson, H. 2005. A method to extract wave tank data using video imagery and its comparison to conventional data collection techniques, Computers & Geosciences, 31, 371–384. http://dx.doi.org/10.1016/j.cageo.2004.10.006

Erikson, L., Larson, M., and Hanson, H. 2005. Prediction of swash motion and run-up including the effects of swash interaction, Coastal Engineering, 52, 285–302. http://dx.doi.org/10.1016/j.coastaleng.2004.12.001

Erikson, L., Larson, M, and Hanson, H. 2007. Laboratory investigation of beach scarp and dune recession due to notching and subsequent failure, Coastal Engineering, 51, 675–696.

Fisher, J. and Overton, M. 1984. Numerical model for dune erosion due to wave uprush, Proceedings of the 20 th Coastal Engineering Conference, ASCE, 1553–1558.

Kogure, T., Aoki, H., Maekado, A., Hirose, T., and Matsukura, Y. 2006. Effect of the development of notches and tension cracks on instability of limestone coastal cliffs in the Ryukyus, Japan, Geomorphology, 80, 236-244. http://dx.doi.org/10.1016/j.geomorph.2006.02.012

Larson, M., Erikson, L., and Hanson, H. 2004. An analytical model to predict dune erosion due to wave impact, Coastal Engineering, 51, 675–696.http://dx.doi.org/10.1016/j.coastaleng.2004.07.003

Nishi, R. and Kraus, N. 1996. Mechanism and calculation of sand dune erosion by storms, Proceedings of the 25 th Coastal Engineering Conference, ASCE, 3034–3047.

Sunamura, T. 1973. Coastal cliff erosion due to waves. Field investigation and laboratory experiments, Journal of the Faculty of Engineering, The University of Tokyo, XXXII(1), 1-86.

Sunamura, T. 1976. Feedback relationship in wave erosion of laboratory rocky coast, Journal of Geology, 84, 427-437.http://dx.doi.org/10.1086/628209

Sunamura, T. 1992a. Geomorphology of rocky coast, John Wiley & Sons, England.

Sunamura, T. 1992b. A wave tank experiment on the erosional mechanism at a cliff base, Earth, Surface, Processes, and Landforms, 7, 333-343. http://dx.doi.org/10.1002/esp.3290070405

Trenhaile, A.S., Pepper, D.A., Trenhaile, R.W., and Dalimonte, M. 1998. Stacks and notches at Hopewell Rocks, New Brunswick, Canada, Earth, Surface, Processes, and Landforms, 23, 975-998.http://dx.doi.org/10.1002/(SICI)1096-9837(1998110)23:11<975::AID-ESP916>3.0.CO;2-K


Full Text: PDF

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