Shortage of Sediments in the Maspalomas Dune Field (Gran Canaria, Canary Islands) Deduced from Analysis of Aerial Photographs, Foraminiferal Content, and Sediment Transport Trends

Abstract

The Maspalomas dune field and adjacent beaches are the most extensive coastal sedimentary environment on the island of Gran Canaria. This area is very important from both a natural and an economic perspective. The analysis of aerial photographs and satellite images from recent decades does not show important shoreline changes for the El Inglés and Maspalomas beaches, which can be considered, consequently, in a state of equilibrium. However, the Maspalomas dune field presents several modifications, such as aeolian corridors associated with beach kiosks, a significant reduction in thickness of the aeolian deposits, and an increase of deflation areas in the underlying substratum. All these are proof of a drastic reduction in sediments. Sediment transport pathways obtained from the grain size parameters of beach samples show an input of sediments from El Inglés beach to Maspalomas dune field, whereas longshore drift is predominant on Maspalomas beach. This grain-scale analysis agrees with previous geomorphologic and wind studies. Foraminiferal content analysis also confirms the input of sediments from El Inglés beach to the dune field, as well as indicating the lack of inputs across Maspalomas beach, on which only seaward fluxes from closer dunes can be expected. Input and sinking areas of the system have been confirmed as well as a notable lack of sediments in the dune area, which is suffering severe erosion because of the shortage of sediment supplies from El Inglés beach.