Aeolian sediment availability in coastal areas defined from sedimentary parameters. Application to a case study in Fuerteventura

Wind characteristics and availability of airborne sediments control aeolian dynamics. Availability of sediments has been only estimated from dune dime nsions. Nevertheless, this method is not valid in serir (stone dessert) and sand sheets deposits, where surface properties better than volume of mater ials define their sediment availability. The area chosen for this study is the Isthmus of Jandia (Fuerteventura, Canary Islands), which presents a hig h diversity of present day aeolian environments. Grain-size and composition al parameters from surface samples permit the design of its sedimentary car tography, which shows spatial and seasonal variations of the aeolian dynami cs. Values of these parameters have been combined by statistical analyses t o obtain a new parameter, lineal combination of mean size, sorting, skewnes s, and carbonate content, which has been named the Aeolian Sediment Availab ility (ASA) parameter. The ASA parameter presents several advantages over t he previous mobility diagrams (mean size vs sorting), since it considers mo re sedimentary variables, has a continuous numerical gradient which permits the plotting of maps of the aeolian sediment availability, and has a clear physical meaning. Dynamics inferred from this parameter are satisfactory c ompared with local wind data, empirical transport rates and landscape unit maps of the area.