Coastal sand dune restoration with an eco-friendly technique

Abstract

Dune restoration projects that integrate vegetation efforts with natural, sustainable, and soft solutions have become increasingly popular in coastal communities. Eco-restored dunes have high aesthetic value and are likely to be more resilient to near-surface wind effects and/or minor storms events. However, environmental-friendly restoration strategies still lack scientific insight from systematic research and the role of eco-restoration in dune erosion resistance and resilience has not yet been rigorously investigated. The question is: how can we optimize eco-friendly solutions in dune ecosystem restoration to maximize the resistance and resilience of coastal dunes against erosion from wind, wave, and storm surge attack? The present paper proposes an innovative colloidal silica-based consolidation technique for coastal sand dunes. A special focus is placed on the description of the experience gained from two pilot field studies started in Salento coastal area, in the south of Italy. The preliminary observations clearly show that mineral colloidal silica increases the mechanical strength of non-cohesive sediments allowing the adopted solution to reduce the volume of dune erosion and the dune scarp retreat rate, thus improving the resistance and resilience of the dune system. Besides furthering our knowledge of coastal erosion, the results of these and future studies will be of value to coastal managers and policy makers responsible for dune restoration projects.

Keywords:

• erosion
• eco-restoration
• sand-colloidal silica mixture
• resistance
• resilience

Acknowledgements

The authors gratefully acknowledge the public administration of Otranto city and the “Area Marina Protetta” at Porto Cesareo for their helpful assistance in organizing the pilot field studies.

Funding

The present work has been supported by the Regione Puglia through the grant to the budget of the project titled “Sperimentazione di tecnologie innovative per il consolidamento di dune costiere (INNO-DUNECOST)”, POR Puglia FESR FSE 2014-2020 - Sub-Azione 1.4.B, Contract n. RM5UKM2.