Morphological changes in dunes as an indicator of anthropogenic interferences in arid dune fields

Cabrera-Vega, L.L., Cruz-Avero, N., Hernández-Calvento, L., Hernández-Cordero, A.I. and Fernández-Cabrera, E., 2013. Morphological changes in dunes as an indicator of anthropogenic interferences in arid dune fields. In: Conley, D.C., Masselink, G., Russell, P.E. and O'Hare, T.J. (eds.)

Coastal dunes systems have been widely modified by human activities, especially in recent decades. Some of the changes have modified the aeolian landforms which characterize these environments. The dune systems of the Canary Islands can be considered as arid systems due to its temperature and rainfall levels. For this reason, the speed at which the geomorphologic process (natural or induced by human activities) occur are more significant than in dune systems located at either temperate or tropical regions. In this sense, the Canary Islands beach-dune systems are ideal for testing the effects of human activity on these environments. This work identifies major alterations, from the 60's, on three dune systems where the tourism activity has developed to a considerable extent: Maspalomas (Gran Canaria), Corralejo (Fuerteventura) and Famara (Lanzarote). To analyse these changes, historical and current aerial photographs and orthophotographs were used, as well as field work. Changes have been classified by the causes that induced them: I) urban development; II) beach equipment; III) beach users; IV) maintenance activities; V) a combination of some of these former causes. Results indicate that urban development is the main cause of the alteration of these dune fields. In Maspalomas and Famara less than 35% of their surfaces are free of human actions capable of producing morphological changes, while in Corralejo this percentage reaches 63%. In the analyzed period, the surface of the dune fields have been reduced, some of the existing dunes have been modified, and new morphologies (natural and artificial) have appeared. The latter process is mostly associated with mismanagement in these areas.