New methodology for describing the equilibrium beach profile applied to the Valencia's beaches

Abstract

Mathematical models used for the understanding of coastal seabed morphology play a key role in beach nourishment projects. These projects have become the fundamental strategy for coastal maintenance during the last few years. Accordingly, the accuracy of these models is vital to optimize the costs of coastal regeneration projects. Planning of such interventions requires methodologies that do not generate uncertainties in their interpretation. A study and comparison of mathematical simulation models of the coastline is carried out in this paper, as well as elements that are part of the model that are a source of uncertainty. The Equilibrium Profile (EP) and the offshore limit corresponding A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTto the Depth of Closure (DoC) have been analysed taking into account different timescale ranges. The results have thus been compared using data sets from three different periods which are identified as present, past and future. Accuracy in data collection for the beach profiles and the definition of the median grain size calculation using collected samples are the two main factors that have been taken into account in this paper. These data can generate high uncertainties and can produce a lack of accuracy in nourishment projects. Together they can generate excessive costs due to possible excess or shortage of sand used for the nourishment.The main goal of this paper is the development of a new methodology to increase the accuracy of the existing equilibrium beach profile models, providing an improvement to the inputs used in such models and in the fitting of the formulae used to obtain seabed shape. This new methodology has been applied and tested on Valencia's beaches.

Flooding of Sandy Beaches in a Changing Climate. The Case of the Balearic Islands (NW Mediterranean)

“…Also, wave projections suggest small reductions in the mean and extreme wave height through the whole basin (Lionello et al, 2017). Considering the beach characteristics, reports on beach morphology in different Mediterranean locations show similar values than those considered here (Falco et al, 2014;Aragonés et al, 2016;Jiménez and Valdemoro, 2019). Therefore, it is safe to assume that the reduction of beach area availability projected for the Balearic Islands can be extrapolated to the rest of the Mediterranean sandy beaches.…”

Gravel beaches nourishment: Modelling the equilibrium beach profile

“…The cross-shore profiles used in this study come from bathymetric data taken in a single period of the year. However, these profiles can be considered valid if we take into account that, as Aragonés et al (2016) studied, the longshore transport of sediments is not relevant in the equilibrium profile, since after comparing the equilibrium profile obtained as the average of 22 years of precision profiles (at least two per year) with the bathymetry profile obtained in a single period, it was observed that the difference was less than 8%. In addition, according to López et al (2016) the profiles used in this study can be considered as the equilibrium profile given that: i) the beach width variation is less than 1 m/year, i. e. the beaches are stable.…”

Artificial neural network modeling of cross-shore profile on sand beaches: The coast of the province of Valencia (Spain)

“…These profiles were divided into fifteen points (x, y), of which yi will be the outputs of the ANNs. The 15 points were chosen so that the xi was constant for all profiles, and reach, at least, the depth of closure (DoC), calculated according Birkemeier (1985) The profiles of a single season are valid (at least in this area) to characterize the profile of the beach, as Aragonés et al (2016a) indicates when comparing these profiles with the mean profile obtained from precision profiles (± 2 cm ) Taken over 20 years in both summer and winter season, the error committed is less than 8%. Therefore, profiles of a single season can be used without making big mistakes.…”