Delimitação de áreas de preservação permanente e definição de classes de enquadramento via SIG: estudo de caso da Bacia Hidrográfica do Córrego de Ouro

Abstract

Water conservation cannot be obtained apart from other natural resources conservation, thus this present study has investigated the challenges of implementing the CONAMA 303/2002 and 357/2005 and has shown the conflicts that should be solved. This case study, which was carried out at the Corrego do Ouro hydrographic bay in the municipality of Santa Maria de Jetibá, located in the mountain region of the state of Espirito Santo, used automatic delimitation methods of the permanent preserved areas based on a hydrologically correct digital elevation model (HCDEM), land use and occupation map, and water quality parameters analysis. The collected data were compiled and processed through a geographical information system; the results were presented on maps and tables. It was verified that the permanent preserved areas (PPA) occupy an area of 387,79 hectares, which corresponds to 62,32% of the bay, and that 61,31% of the areas are preserved, which means a significant amount of conservation. The automatic delimitation method of the PPA's can be safely applied to water bays using a 1:50.000 scale to generate a hydrologically correct digital elevation model, however, the HCDEM accuracy must be tested so as to identify nonconformity areas to allow corrections, otherwise the generated model should be discarded. The framing goals for all sampled points, according to preponderant identified uses, were not met when they analyzed the water quality parameters and compared them to the CONAMA 357/2005. During the proposed framing simulation, it was verified that the water quality, identified at the spring of the studied bay, did not contribute to maintaining the predetermined limits for the Santa Maria da Vitória river. Analysis and descriptions of future scenarios indicate that the restoration of the permanent preserved areas, if not broadly discussed, could increase land use and occupation conflicts, as well as influence the local economy negatively.