Impact of paleo-rainfall events in the South Atlantic Convergence Zone (SACZ) and human pressures since ~ 1950 in southeastern Brazil: Paraty and Saco de Mamanguá

A significant decline in rainfall and a sharp increase in sediment accumulation since the 1980s, driven by urbanization, deforestation, agriculture, and dredging, have been identified in Paraty and Saco de Mamanguá, southeastern Brazil. The study, using radiometric dating (210Pb and 137Cs) and geochemical analysis of sediment cores from Ilha Grande Bay, reveals that while moisture levels were higher before ~2000, human activities have since exacerbated environmental degradation, including silting, eutrophication, and pollution by toxic elements like Cu, Pb, Sn, Zn, and As. Additionally, the research highlights the impact of extreme rainfall events linked to the South Atlantic Convergence Zone (SACZ), which has intensified landslides in slope zones, particularly since ~1970. These findings underscore the dual threat of climate change and anthropogenic pressures on coastal ecosystems, necessitating further investigation into mega-rainfall events in densely populated areas.

Farhangi, V., Martins, M. V. A., Figueira, R. C. L., de Lima Ferreira, P. A., Pereira, E., Lara, D., do Nascimento, C. A., Hohenegger, J., Saibro, M. B., Guerra, J. V., Rebouças, R. C., Silva, C. G., da Silva, A. L. C., Dias, F. F., Dino, R., Coe, H. H. G., & Rocha, F. (2025). Impact of paleo-rainfall events in the South Atlantic Convergence Zone (SACZ) and human pressures since ~ 1950 in southeastern Brazil: Paraty and Saco de Mamanguá. Environmental Earth Sciences, 84(11). https://doi.org/10.1007/s12665-025-12248-7