Ecosystem Services Provided by Geodiversity: Qualitative and Quantitative Assessment of the Coastline of the State of Piauí, Northeastern Brazil

Abstract This research presents a methodological proposal for the qualitative (inventory) and quantitative evaluation of ecosystem services (ES) provided by geodiversity, applied to the coast of the state of Piauí, northeastern Brazil, aiming at the valorization, recognition, and propagation of geodiversity and its ES, as a geoconservation strategy. The study area is located on the northern Brazilian coast and presents a complex morphostructural context, with sandy beaches, dune fields, rocky promontories, reefs, estuarine systems, a deltaic plain, and other elements of its geodiversity. For the assessment of the ES provided by geodiversity on the coast of Piauí, adaptations of the methodologies of Sharples (2002), Brilha (2005) and Gray (2013) were used in the inventory stage, as well as adaptations of Gray (2013), in addition to a proposed quantitative matrix in the quantification stage. Aiming to delineate sites of geodiversity interest related to ecosystem values, the study proposes the use of a new term, Geoecosite (GEco), which indicates Geodiversity Sites with Ecosystem Interest. As a result, a total of ten GEcos were inventoried on the coast of Piauí based on the SE (regulating, supporting, provisioning, cultural, and knowledge) provided by the components of geodiversity, which were subsequently quantified according to the different criteria established in this stage. Through the evaluation, the GEcos presented several ecosystem benefits, both tangible and intangible, contributing to the appreciation and local geoscientific knowledge.