Espinoza, J.M.A.; Alves, D.C.L.; Albuquerque, M.G.; Espinoza, T.A., and Gonzaga, B.A., 2024. Using satellite imagery from the LANDSAT series to analyze coastal dune coverage dynamics. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 564-568. Charlotte (North Carolina), ISSN 0749-0208.

The coastal zone can be understood as a region of interaction between the continent, continental waters, the atmosphere and the ocean. It contains the coastal plain, dunes, marshes, marshes and mangroves, lagoons, estuaries, and the ocean. In this coastal zone, the dunes represent one of the main features, resulting from geomorphological processes of wind origin, characterized by sedimentary deposits formed by the interaction of sand grains, wind action and the presence of vegetation. This work presents an analysis of the dune coverage of a system of frontal and embryonic dunes in a coastal stretch belonging to the municipality of Garopaba, Santa Catarina/Brazil. Methodologically, image data from the TM/LANDSAT-5 and OLI/LANDSAT-8 orbital sensors were used for the period 1985-2020, in two main stages: (I) Determination of the dune area for the study area; and, (II) Determination of the spatio-temporal patterns of the dynamics of this dune cover. To this end, data pre-processing was applied (radiometric correction, atmospheric correction using the DOS technique, geometric correction with co-registration and adjustment of coordinates and cropping for area; later, the scenes were converted to the representation system of IHS colors, allowing the chromatic identification of targets, with the application of a threshold on the scenes, which generated a dune scene for each date and the detection of changes through the change vector technique, applied through the subtraction of two images of subsequent dunes (e.g.: 1995 - 1985). As a result, the greatest losses were mainly concentrated on the windward side of these dunes, while the greatest sedimentary gains were concentrated on the leeward side, according to the transgressive nature of these morphologies. Between 2005 and 2020 there was a 39% reduction in the area of dunes in the area (93.6 ha), with urban growth over the dunes corresponding to 34 hectares, with the urban area being responsible for 44% of the total area of suppressed dunes. This case study shows the potential of using remote sensing data to study coastal morphology, especially dunes.