Dinâmica da paisagem costeira e os impactos da elevação do nível médio do mar na reserva extrativista marinha da baía do Iguape, no Recôncavo Baiano

• Autor(a) principal: Souza, Ivonice Sena de
• Data de Publicação: 2023
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/jspui/handle/riufs/19036
• topic: Ecologia Costeira; Bahia; Reservas naturais; Plantas do manguezal; Impacto ambiental; Salinidade; Comunidades pesqueiras; Elevação das marés; Manguezal; Modelagem ambiental; Zona costeira; Fishing communities; Tidal elevation; Mangroves; Environmental modeling; Coastal zone; Elevación de mareas; Manglares; Modelación ambiental; Zona coster; CIENCIAS HUMANAS::GEOGRAFIA

Coastal areas are exposed to environmental risks caused by climate change accelerated by human actions and, among their consequences, the probable Rise in the Average Relative Sea Level (ENMRM) stands out. Projections point to a scenario of impacts on several cities and coastal ecosystems until the end of the 21st century. In this context, it is noteworthy that of all the elements that make up the coastal landscape, the mangrove ecosystem is considered the most vulnerable to the impacts of ENMRM due to the increase in salinity that could be caused by this event. Research by the Intergovernmental Panel on Climate Change (IPCC, 2022) predicts an alarming scenario by 2100, when it could reach more than one meter. In this sense, the study's general objective is to analyze the systemic effects related to the rise in average sea level on mangroves and fishing communities in the Marine Extractive Reserve of Baía do Iguape (RESEX Baía do Iguape), located in Recôncavo Baiano. In the spatial outline, it was decided to generate a 500 meter buffer around the RESEX polygon. The perception of territory for traditional communities is not always limited to legal demarcations. In this sense, we sought, through a spatially explicit model, based on cellular automata and Geographic Information System (GIS), to identify patterns of resistance, migration and/or flooding of these mangroves. From this perspective, the scientific method that directs this study is hypothetical-deductive, based on the integrated analysis of the landscape from a systemic perspective. The methodological procedures included office and field stages, the first corresponding to bibliographical research, organization of a geographic database in a GIS environment, data tabulation, treatment and generation of cartographic products, digital processing of satellite images, creation of maps of land use and cover, land surface temperature estimates and modeling of ENMRM impacts on mangroves. The field stage corresponds to on-site observation and verification, collection of geographic coordinates, photographic records, floristic identification, measurements of the structure of the mangroves and interviews with fishermen and shellfish gatherers. The simulation of impacts resulting from sea level rise covers the time range from 2022 to 2100. When the ENMRM occurs towards the continent, mangrove areas can be flooded/eroded. At RESEX Baía do Iguape, in the last 36 years (1986 to 2022), there has been an expansion of the mangrove area. When estimating the temperature of the earth's surface, it was detected that the anthropized areas and the apicum presented the highest temperatures and the areas of dense rainforests, the lowest. According to the results obtained from the modeling, the migrated mangrove area will not compensate for the extinct mangrove area. The loss of mangroves will result in a reduction in fishing and shellfishing spaces. The advance of mangroves towards the continent will occur in areas of apicum and vegetation. Areas favorable to mangrove migration are threatened and are subject to anthropogenic use. Furthermore, the results indicate that the mangrove ecosystem will encounter barriers that will make its migration to the continent unfeasible. The migration of mangroves will be conditioned on the use that will be given to the surrounding land. Human activities can accelerate the process of degradation of mangroves in the face of rising sea levels, when these act as factors that make the migration of mangroves to the continent unfeasible. In the reserve, three species of mangrove were recorded, distributed in Laguncularia racemosa (white mangrove), Rhizophora mangle (red mangrove) and Avicennia germinans (black mangrove). At this juncture, environmental simulations are essential in the search for understanding mangrove response patterns to the possible MRSLR event, especially in areas of complex use and occupation, where there is intense human occupation and exploitation, allowing the generation of diagnoses and prognoses for a better management of coastal space, assisting in the development of adaptation strategies in the face of ENMRM. The use of modeling techniques is essential to predict and understand possible impacts before they occur.