NEW ANALYTICAL APPROACHES FOR THE ASSESSMENT OF SHORELINE EVOLUTION IN THE VICINITY OF COASTAL STRUCTURES.

Antonios Valsamidis, Dominic E. Reeve

Abstract


In this study new analytical schemes are presented for the assessment of the shoreline evolution in the vicinity of a newly constructed coastal defence on the beach of Borth in Wales. The innovation introduced in this study is that the analytical schemes which were used exceed the usual purpose of analytical modelling to describe simplified cases of beach change. Therefore, the new complex coastal defence system, recorded data of the local wave climate and a river-mouth which acts a source of sediment discharge could be used as input data for the assessment of the shoreline evolution. Initially, the coastal defence system was represented by a single impermeable groyne. The subsequent shoreline change was described mathematically by a relative partial differential equation (diffusion equation). The analytical solution to this equation was produced by using Laplace transforms, and the evaluation of this solution was executed with a Heaviside technique which allowed an arbitrary sequence of wave incidents to be taken into account. Then, the coastal defence scheme was represented by 2 groynes and artificial beach nourishment. The analytical solution to the relative partial differential equation describing the shoreline evolution was produced with the use of Fourier cosine transforms. Results for both simulations demonstrate the capability of the introduced analytical methods to deal with complicated situations but also their constraints

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References


Walton and Dean (2011): Shoreline Change at an Infinite Jetty for Wave Time Series, Continental Shelf Research, ASCE, vol . 31 (14), pp. 1474-1480.

Valsamidis, Cai and Reeve (2013): Modelling beach-structure interaction using a Heaviside technique: application and validation, Journal of Coastal Research, Special Issue 65, CERF, pp. 410-445.

Zacharioudaki and Reeve (2008): Semi-analytical Solutions of Shoreline Response to Time-Varying Wave Conditions, Journal of Waterway, Port, Coastal, and Ocean Engineering, ASCE, vol. 134(5), pp. 265-274.

Reeve (2006): Explicit Expression for Beach Response to Non-Stationary Forcing near a Groyne, Journal of Waterway, Port, Coastal, and Ocean Engineering , ASCE, vol. 132(2), pp.125-132.




DOI: https://doi.org/10.9753/icce.v34.posters.6