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Airflow dynamics, vegetation and aeolian erosive processes in a shadow zone leeward of a resort in an arid transgressive dune system ABSTRACT Structures and infrastructures can modify aeolian sedimentary dynamics as has occurred in the arid transgressive dunefield of Maspalomas (Gran Canaria, Canary Islands), where an aeolian shadow zone has been formed leeward of a tourist resort (Playa del Inglés). The aim of this paper is to examine and statistically analyse the influences of vegetation and topography on wind flow across this shadow zone. An experiment was carried out in March 2017, collecting wind speed and direction from 5 transects with anemometers at 0.40 m height. Simultaneously, a drone flight was carried out, from which an orthophoto and digital elevation and surface models (DEM and DSM)were obtained. Distance from the resort, and the presence of vegetation were found to influence transects dominated by erosional processes. Transects that do not display erosional processes were primarily affected by the presence of vegetation. The local wind field changes at a similar distance across the transects downwind from the resorts indicating an acceleration or reattachment of the wind at this distance downwind. The vegetation role in this aeolian shadow zone could be a key to the future evolution of the area resulting in either further stabilization, or alternatively, the continued deflation of the area.

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Underwater gliders constitute a technology in active development, which has proven very promising in Ocean Research because of its relative low cost and long mission range. Due to their low surge speed, however, gliders are strongly affected by ocean currents, making path planning a crucial tool for this type of vehicles. In this work, we present a novel path planning algorithm for gliders based on iterative optimization that shows promising results in realistic simulations. This method reflects accurately the vehicle operation pattern and exhibits a better performance when compared with alternative approaches that are compared in this paper.