MONITORAMENTO MORFODINÂMICO INTEGRADO E CIÊNCIA CIDADÃ EM PRAIAS DE MACROMARÉ EM SÃO LUÍS-MA

Abstract

This study analyzes coastal dynamics along the coast of São Luís (MA) using an integrated approach that combines high-resolution geotechnologies and citizen science. The coastal zone of Ilha do Maranhão, characterized by a semi-diurnal macrotidal regime with amplitudes of up to 6.5 m, presents high morphodynamic complexity and vulnerability to erosive processes. The methodology consisted of topographic monitoring of Olho d'Água Beach using GNSS-RTK and photogrammetry to generate Digital Elevation Models (DEMs) and calculate sediment balance, in addition to implementing the CoastSnap-MA project on Ponta d'Areia and Olho d'Água beaches to assess social engagement in participatory monitoring. The results of the morphological analysis indicate a seasonal control of the system: during the dry season, the intensification of waves and winds favors erosive processes and the formation of tidal channels, with the low tide bar/rip stage predominating. During the rainy season, the reduction in hydrodynamic energy promotes the redistribution and retention of sediments, resulting in smoother profiles. The lower sectors of the beach (mid- and lower intertidal zones) were identified as the most vulnerable, with altimetric variations of up to 0.5 m. Regarding citizen science, CoastSnap-MA registered 1,198 participants from 26 Brazilian states and 10 countries, demonstrating high potential for environmental awareness and dissemination of ocean culture, although engagement was asymmetrical among beaches due to infrastructure factors and user flow. It is concluded that integrating high-precision methods with community participation offers a robust and innovative database to support coastal management strategies and adaptation to climate change in the region.