Controls on sediment dynamics and medium-term morphological change in a barred microtidal beach (Cala Millor, Mallorca, Western Mediterranean)

摘要

This paper describes the sedimentological and morphological evolution of a microtidal beach over an eight-month period under varying hydrodynamic conditions. During the monitoring a set of transverse to crescentic bars migrated onshore welded to the upper beach and then they were flattened under energetic wave conditions. The grain size distribution of surficial sediments did vary consistently across the beach profile and temporal changes in the sedimentology were mostly related to the seasonal morphological response. From our results we can state that changes in the beach morphology resulting from erosion and deposition might induce, at least to some degree, concomitant changes in the beach when hydrodynamics exceed some intensity and duration levels (Hs>1 m). Wave climate, rather than wave forcing is the major control on sediment and morphological change co-variation.