Aplicação de sistema digital de modelagem costeira para análise da variação posicional da linha de costa em praias

Abstract

Erosion is one of the most frequent problems in coastal environments and considered a global phenomenon. In addition to natural physical factors, some human activities contribute to this process. Coastal zones represent transitional environments, characterized by continuous changes at different temporal and spatial scales, being influenced by oceanographic, fluvial, climatic and anthropogenic processes. Over the years, several of these changes have been monitored, and discovering which variables are most likely to trigger negative impacts is currently essential. Geoprocessing is frequently used in the management of coastal environments, enabling temporal and spatial analyzes through satellite images. The aim of the work was to carry out an analysis of the spatio-temporal variability of the coastline of the coastal region of the city of Maceió-AL, specifically on the beaches of Cruz das Almas, Jatiúca and Ponta Verde. To determine the positional dynamics of the coastline of the beaches in the municipality, a free open source tool called Coastal Analyst System from Space Imagery Engine CASSIE was adopted. The period analyzed covered the years 1991 to 2023 (32 years). After this phase, quantitative data on the occurrence of erosion processes was improved for a more efficient organization of results in tables. The layouts were created in the free software QGIS version 3.30 's-Hertogenbosch for better understanding and analysis of the results obtained for the study area. The results showed erosion processes along the studied coastline, with accreted and eroded areas, as well as stable ones. Among the years studied, sector 3, located on Ponta Verde beach, presented the highest erosion rate with an average of -0.7688 m/year. Therefore, it is essential that actions aimed at planning and controlling urban expansion in the coastal region of the city of Maceió-AL are developed by decision makers.