Morphological evolution in the migrating dune of Valdevaqueros (SW Spain) during an eleven-year period

Abstract

Located in Tarifa, near the Strait of Gibraltar, the migration of Valdevaqueros dune was controlled by sand extractions for building purpose. As the Spanish Shore Act was approved in 1988, the sale of sand was forbidden and the dune started to move forward, burying the leeward pine wood and the only road to Maspalomas village. Consequently, six topographic levellings have been taken during the last eleven years. Sedimentary granulometries and meteorological features were taken into account. D50 values have been calculated for dune foot, windward and dune top. Wind speed threshold is estimated above 15 km/h. East winds are responsible for dune movement, whose advance rate has reached very high values (over 18 m/year). Slope and volumetric changes have been determined, providing a clearer explanation of the dune evolution