Morphometric characterization of foredunes along the coast of northern Spain

Abstract

Foredunes are defined as the first shore-parallel dune ridges adjacent to stable and prograding beaches, formed on the backshore by aeolian sand deposition influenced by vegetation. Foredunes have the important functions for mitigating impacts caused by extreme events, providing sediment to the beaches during storm and accumulating sediment again under fair weather wave conditions. Mainly for this reason, there is currently great interest in preserving, building or recovering foredunes. On a long-term timescale (decades), foredunes are recognized as exhibiting possible equilibrium conditions. The identification of this condition is of interest to projects involving the recovery and creation of foredune/beach systems. Therefore, the main objective of this work is to identify the morphometric characteristics of equilibrium foredunes and the interrelations between the morphometric parameters of height, width, volume and maximum slope (allometric relationships). To reach this objective, 193 foredune/subaerial beach profiles from along the northern coast of Spain that have characteristics close to equilibrium conditions were evaluated. The results indicate that foredune size can vary significantly; however, strong correlations between morphometric parameters have been verified and allometric relationships between foredune volume, height, width and maximum slope are proposed.