Evaluation of Soft Protection Techniques in Barrier Islands by Monitoring Programs: Case Studies from Ria Formosa (Algarve-Portugal)

Coastal management and protection by soft techniques is becoming to be widely used as an alternative to traditional hard defences. These techniques have fewer environmental impacts and, therefore, are a better solution for environmentally sensitive areas, such as barrier islands. The Natural Park of Ria Formosa (Portugal) used three different soft techniques for the coastal management of its barrier island system: dune nourishment at Caceia Peninsula, inlet opening at Ancão Peninsula, and a general program of beach replenishment, starting at Cabanas Island. All actions were monitored, providing a comprehensive understanding of the natural evolution of each area after interventions. In general, all actions performed well (with minor problems) reaching the expected management goals. A clear trend towards re-establishment of natural conditions was observed after interventions. The techniques did not disrupt the natural evolution of the system and did not cause any negative side effect, as it would be the case if hard techniques were used. The environmental values were maintained and landscape impacts were minor, showing that natural systems with high environmental and economical importance can be managed by soft protection techniques.