The hydrographic basin of the Mocajuba River has been densely occupied by the expansion of human activities. In this way, anthropization jeopardizes the permanence of the natural ecosystems and mangroves in this region. In this context, this work presents the dynamics of the landscape in the Mocajuba River basin between 1999 and 2018 and its implications for the natural fragility of the basin and the continuity of the mangroves in this region. To this end, the research is divided into the following items: (1) Analysis of land use and land cover in the hydrographic basin of Rio Mocajuba - PA, using the Object Oriented Classification (GEOBIA) and the Google Earth Engine platform as methods (GHG), in conjunction with the Random Forest classifier. (2) Application of the Potential and Emerging Environmental Fragility methodology, using natural data from the basin (pedology, geological units, altimetry and rainfall) in conjunction with anthropogenic data (land use and cover). (3) Temporal analysis of the mangroves in the basin between 1984 and 2018, observing the expansion and regression of this ecosystem, as well as the anthropic and environmental tensors to which they are susceptible. The land use and land cover classification methodologies presented different quantifications and accuracy. For 1999, the GEOBIA and Random Forest classification presented a Kappa coefficient of 0.79 and 0.92, respectively. For 2018, the coefficient was 0.73 and 0.8, respectively. For both methodologies, the class of Forestry Formation suffered a decrease and Non-Forestry increased. For the Mangrove class, the GEOBIA classification quantified an increase and the Random Forest decrease. In the environmental fragility methodology, the levels of potential and emerging fragility obtained were low, medium and high. Where 19.92%, 76.67% and 3.41% of the basin showed low, medium and high potential fragility, respectively. For emergent fragility, the mangrove and non-forest areas increased the natural fragility of the basin and the forest formation class provided an attenuation of this. In this case, the areas of low, medium and high emerging fragility were quantified at 18.39%, 67.57% and 14.04%, respectively. Mangrove areas decreased between 1984-1999 and 1999-2018. The data presented confirm the expansion of the anthropization of the basin and the interference of human activities in the dynamics and response of the mangroves in the face of natural tensors. As confirmed by the increase in the natural fragility of the basin provided by the expansion of these activities. In this way, the research becomes relevant for providing a systemic analysis between different areas, seeking to understand the functioning of the basin ecosystem, assisting in future research and initiatives.
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