Coastal geoindicators: Towards the establishment of a common framework for sandy coastal environments

Geoindicators are used to describe reference situations and measure changes and trends in physical environment over time. They provide a simplified form to communicate complex data and information, and constitute a facilitator mechanism in the dialog among stakeholders. In this work, a review on the use of geoindicators in sandy coastal environments is performed. It was found that, despite the obvious advantages in reporting the state of the coast using geoindicators, their generalized adoption seems to be stalled and is limited to a few management settings and particular projects. The existence of a myriad of coastal geoindicators, that frequently are poorly defined, is identified as the major difficulty in their widespread use. The present work aims to contribute towards the establishment of a common framework for coastal geoindicators, focusing on sandy coastal environments. The main objective of the compilation and definition of the indicators herein presented is to simplify and clarify their designations, and objectively present the measurement and reporting criteria aiming at a consensus-based approach. Sixteen coastal geoindicators are identified as relevant for the description of the state of beach, coastal dunes, and coastal barrier environments. This effort contributes to the adoption of coastal geoindicators as an effective communication tool leading to a more standardized report on the state of the coastal zone.