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

Abstract

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 ofthe Canary Islands can be consideredas arid systemsdue to its temperature and rainfall levels. For this reason, the speed at which the geomorphologic process (natural or induced by human activities) occur aremoresignificant 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 ofhuman activity on theseenvironments. 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 currentaerial photographsandorthophotographswere used, as well as field work. Changes have beenclassified by the causes that induced them: I) urban development; II) beach equipment; III) beach users; IV) maintenance activities; V) acombination of some of theseformer 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 beenmodified,and new morphologies(natural and artificial) have appeared. The latter process is mostly associated with mismanagementin these areas