%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Schepper, R.
%A Almar, Rafaël
%A Bergsma, E.
%A de Vries, S.
%A Reniers, A.
%A Davidson, M.
%A Splinter, K.
%T Modelling cross-shore shoreline change on multiple timescales and their interactions
%D 2021
%L fdi:010082246
%G ENG
%J Journal of Marine Science and Engineering
%K equilibrium shoreline modelling ; ShoreFor ; cross-shore sediment ; transport ; multiple timescales
%K AUSTRALIE ; VIET NAM ; NOUVELLE ZELANDE
%M ISI:000667022200001
%N 6
%P 582 [27 ]
%R 10.3390/jmse9060582
%U https://www.documentation.ird.fr/hor/fdi:010082246
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2021-08/010082246.pdf
%V 9
%W Horizon (IRD)
%X In this paper, a new approach to model wave-driven, cross-shore shoreline change incorporating multiple timescales is introduced. As a base, we use the equilibrium shoreline prediction model ShoreFor that accounts for a single timescale only. High-resolution shoreline data collected at three distinctly different study sites is used to train the new data-driven model. In addition to the direct forcing approach used in most models, here two additional terms are introduced: a time-upscaling and a time-downscaling term. The upscaling term accounts for the persistent effect of short-term events, such as storms, on the shoreline position. The downscaling term accounts for the effect of long-term shoreline modulations, caused by, for example, climate variability, on shorter event impacts. The multi-timescale model shows improvement compared to the original ShoreFor model (a normalized mean square error improvement during validation of 18 to 59%) at the three contrasted sandy beaches. Moreover, it gains insight in the various timescales (storms to inter-annual) and reveals their interactions that cause shoreline change. We find that extreme forcing events have a persistent shoreline impact and cause 57-73% of the shoreline variability at the three sites. Moreover, long-term shoreline trends affect short-term forcing event impacts and determine 20-27% of the shoreline variability.
%$ 032 ; 020