Assessing the geomorphological vulnerability of arid beach-dune systems

In this study, an arid dune vulnerability index (ADVI) is developed using a system of indicators to evaluate the geomorphological vulnerability of beach-dune systems of arid regions. The indicators are comprised of three analytical dimensions (susceptibility, exposure and resilience) and their corresponding sub-indices and variables and were assessed for eleven sites located in four aeolian sedimentary systems of the Canary archipelago (Spain). The selected sites have varying geomorphological characteristics, vegetation types, marine and wind conditions and human pressure degrees, and have seen different trends in their geomorphological evolution since 1960. The eleven sites were separated into three groups according to their different conservation status and different management needs, and the results of the ADVI dimensions and variables were compared and analyzed for these three groups. In general, the results obtained in the analyzed sites reveal that susceptibility and exposure dimensions are related to low-moderate values, while resilience was high. Only one site presented a state of critical vulnerability, due to the loss of its capacity to maintain its geomorphological function in recent decades. Given the lack of knowledge about geomorphological vulnerability processes in foredunes of arid regions, ADVI is the first approximation to geomorphological diagnostic in these environments and can be useful for managers.