COMPARATIVE EVALUATION OF AERIAL AND SATELLITE IMAGES FOR MAPPING SEAGRASS MEADOWS IN THE MARINE-COASTAL ZONE NORTH OF THE PORT OF OLBIA: METHODOLOGICAL APPROACH

Abstract

Seagrass meadows are protected because they are threatened by human activities and climate change. Their protection plays a fundamental role in the revision of the "Regional Strategy for Adaptation to Climate Change" carried out by the Region of Sardinia. Remote sensing is a cost-effective tool to survey large areas of coastline. In this study, seagrass meadows in the marine coastal area of Olbia were mapped in a GIS environment using aerial and satellite remote sensing for 2019. Although the satellite image is characterised by a loss of detail compared to the high-resolution orthophoto, it proves to be advantageous for the purpose of subsequent large-scale analysis due to the high mapping speed, the considerable availability of images with higher coverage and, consequently, the visibility of the lower meadow limit. The result is a methodology for producing a habitat distribution map representing a first step in the implementation of an automatic classification procedure at a regional level.