Mapeamento dos remanescentes de manguezal, a partir da interpretação de ortofotos coloridas, e análise dos vetores de pressão antrópica, como subsídio ao planejamento para conservação do ecossistema no Estado do Rio de Janeiro

Abstract

Mangrove is a coastal system that occurs in tropical and sub-tropical regions of the planet, occupying entremares zone of oceans, and featured by the presence of arbórea vegetation very much adapted to adverses conditions of salinity, substractm low oxygenation and periodic submersion. The pressure over the mangrove in Rio de Janeiro have been intensifeid in the last decades and are associated to vectors such as landfills, deforestation, real state speculation and disorganized occupation, infrastructure works, sewage discharge and several residues, and overexploitation of fishing resources. Considering the nonexistence mapping integrated and updated of the remaining mangroves, indicating it s location and sizing, the present study sought to supply this demand, building a consistent subsidy for analyses the main vectors they are exposed to. It sought too, to manage a proposal of strategic actions for the maintenance and monitoring of this ecosystem. The knowledge of the space distribution and the dimensions of these remaining mangroves is directly related to the fishing activity, the stability of the coast line, the tourism activities, the subsistence of many people that live in these regions and also the global climate changes. The analyse of the pressure vectors developed on this study, followed the criterion of partitioning this territory in ten hydrographics regions enabling an environmental planning. This mapping was elaborated basicly from visual interpretation of colorful orthophotos taken in 2005 and carefully checked to identify the terrestrial truth. The mangrove mapping in Rio de Janeiro in scale 1:10.000, resulted in a total remaining area of approximately 17.720 ha, distributed in seven hydrographics regions located in the fluminense coast line, occurring in a more expressive way in 3 of theme. The study contemplated the survey and systematization of cartographic elements and remote sensing mapping the remaining mangroves, identification and analysis of main vectors and pressure over them, from adaptation of the Analysis of the Casual Chain metodology and proposed actions to subsidize the implementation of State Politics for the maintenance of Mangroves in the State of Rio de Janeiro. Finally, were presented proposals of actions to resume the discussion over the management and maintenance of mangrove in Rio de Janeiro, subdivided in the following levels: operating, planning and political. The implementation of public politics integrated is indispensable for the social, economic and environmental development in our state.