Manejo de Bacias Hidrográficas e sua influência sobre os Recursos Hídricos: Estudo de Caso na Bacia Hidrográfica do Rio Benfica, Região Metropolitana de Belém/PA

Abstract

Bacias hidrográficas são consideradas unidades de estudo para o gerenciamento dos recursos hídricos, bem como para o planejamento adequado de diferentes usos e ocupação do solo, visto a necessidade de acesso à água. A Bacia Hidrográfica do Rio Benfica - BHRB, localizada na Região Metropolitana de Belém (RMB), apresenta uma urbanização desordenada, suprimindo áreas verdes e as margens dos cursos d’água, potencializando processos erosivos e assoreamentos dos rios. Objetivou-se com este trabalho avaliar a influência de diferentes usos e ocupação do solo, associada à declividade e ao escoamento superficial, sobre os recursos hídricos da BHRB, através de técnicas de geoprocessamento. Imagens e arquivos vetoriais disponibilizados por diferentes Instituições foram obtidos e processados no software ArcGis versão 10.1. Os resultados demonstraram que a área da BHRB é predominantemente urbanizada e plana e, a maioria das direções de fluxo do escoamento superficial convergem para a sua foz (sentido Norte-Noroeste). Os índices físicos apontam que a bacia apresenta tendência a enchentes e suscetibilidade a inundações. Verificou-se também, com a composição uso do solo, declividade e escoamento superficial, que, sobre as áreas urbanizadas, há o predomínio de pontos de concentração do fluxo de escoamento, onde há a ocorrência de inundação. Mediante os resultados, verificou-se necessidade da reconstituição de áreas verdes e da criação e implementação de um Plano de Recursos Hídricos (PRH) para a bacia. Faz-se necessária a implementação de políticas públicas voltadas para o saneamento básico e fiscalização das áreas de preservação ambiental na área da BHRB. Management of Hydrographic Basins and their influence on Water Resources: Case Study in the Hydrographic Basin of the Benfica River, Metropolitan Region of Belém/PA A B S T R A C TRiver basins are study units for the management of water resources, as well as for the proper planning of different land uses and occupations. The Benfica River Basin - BRB, located in the Metropolitan Region of Belém (MRB), Pará, Brazil, has a disorderly urbanization on the banks of the watercourses, suppressing green areas and intensifying erosive processes and siltation of rivers. The objective of this study was to evaluate the influence of different land uses and occupations associated with slope and surface runoff on the water resources of BRB through geoprocessing techniques. Vector images and files made available by different institutions were obtained and processed in ArcGis software version 10.1. The results showed that the BRB area is predominantly urbanized and flat, and most surface runoff directions converge to its mouth (North-Northwest direction). The physical indices indicate that the basin is prone to flood and susceptible to inundation. It was also verified with the composition of land use, slope and surface runoff that, over urbanized areas, there is a predominance of points of flow concentration, where flooding occurs. The results pointed to the need for reconstitution of green areas and creation and implementation of a Water Resources Plan (WRP) for the studied basin. It is necessary to implement public policies aimed at basic sanitation and supervision of environmental preservation areas in the BRB area.Keywords: Geoprocessing. Morphometric characteristics. Land use and occupation. Hydrology. Management of Hydrographic Basins and their influence on Water Resources: Case Study in the Hydrographic Basin of the Benfica River, Metropolitan Region of Belém/PA A B S T R A C TRiver basins are study units for the management of water resources, as well as for the proper planning of different land uses and occupations. The Benfica River Basin - BRB, located in the Metropolitan Region of Belém (MRB), Pará, Brazil, has a disorderly urbanization on the banks of the watercourses, suppressing green areas and intensifying erosive processes and siltation of rivers. The objective of this study was to evaluate the influence of different land uses and occupations associated with slope and surface runoff on the water resources of BRB through geoprocessing techniques. Vector images and files made available by different institutions were obtained and processed in ArcGis software version 10.1. The results showed that the BRB area is predominantly urbanized and flat, and most surface runoff directions converge to its mouth (North-Northwest direction). The physical indices indicate that the basin is prone to flood and susceptible to inundation. It was also verified with the composition of land use, slope and surface runoff that, over urbanized areas, there is a predominance of points of flow concentration, where flooding occurs. The results pointed to the need for reconstitution of green areas and creation and implementation of a Water Resources Plan (WRP) for the studied basin. It is necessary to implement public policies aimed at basic sanitation and supervision of environmental preservation areas in the BRB area.Keywords: Geoprocessing. Morphometric characteristics. Land use and occupation. Hydrology.