Análise da taxa de variação da linha de preamar média em 2005 e 2017, no litoral sul do município de Maragogi – estado de Alagoas – Brasil

Abstract

In the dynamics of the coastline, sediments are moved to the beach, or removed, resulting in progradation, generally when there is an increase in sediment deposits, or retrogradation when there is a greater erosion process. This work aims to analyze the rate of variation of the average high tide line in the stretch of the south coast of the municipality of Maragogi, state of Alagoas - Brazil, between the years 2005 and 2017. Firstly, a literature review was carried out, followed by the selection satellite images, georeferencing, creation of control points and variation of the average high tide line. Then, the data was tabulated and processed. Finally, the maps were created and the final text was produced. The study area presents a greater number of erosion processes in its extension, with an average annual variation of -0.13 m during the years 2005 and 2017. The areas in which the greatest retrogradation occurred are located in front of the areas more densely urbanized, especially on its southern coast. The least urbanized areas present occasional progradation and are located close to the mouths of the Maragogi and Paus rivers. Given these conditions, a more effective intervention by public authorities is necessary, coupled with the awareness of entrepreneurs and residents, regarding the protection of their natural vegetation, in an attempt to prevent the advancement of retrogradation in the study area.