Evolución morfológica de un campo dunar costero en regeneraciónplaya de Laida (Reserva de la Biosfera de Urdaibai, País Vasco)

Resumen

Promoted by local authorities, a coastal sand-dune regeneration project in the Laida beach (Biosphere Reserve of Urdaibai) started in October 2001. During the following two years, two different phases of morphological development were observed on the sand accumulation. The first year (2001-2002) showed a rapid vertical sand sedimentation (agradational profile) particularly concentrated on the dune crest. In all, 3708 m3 of sand were accumulated during this first year. Onthe other side, the second year (2002-2003) exhibited a lateral sedimentary growth on the dune flanks (progradational profile). In all, 3500 m3 of sand were deposited during the second year. The observed contrast between the two annual sedimentary accumulation profiles was caused by the presence of the sand-catchers during the first year,; and by the pre-existing sand dune capturing sediment from the bidirectional wind (NW and SE) during the second year. This study will allow to construct an evolutionary model of sand-dune regeneration on the Cantabrian coastal area.