Abstract

In 1991, the Integrated Water Resources Management System (SIGRHI) in the State of São Paulo adopted the watershed as a territorial unit for studies, integrated planning and sustainable development. The morphometric analysis of small watersheds, which involves the characterization of geometric parameters, relief, drainage network, combined with land use and occupation, may constitute an important model for environmental analysis of larger watersheds. This study aimed at characterization of the morphometry in the Areal river basin, in the city of Taubaté, São Paulo. The study found 1.89 km² of area, 7.44 km of perimeter and 3.11 km in length of the basin axis, which allowed the calculation of the compactness coefficient (Kc = 1.51), form factor, (F = 0.195) and circularity index (CI = 0.43), indicating that under normal precipitation conditions, this basin is unlikely to be flooded, due to the distance from the unit, leading to smaller concentrate outflow. The results obtained for the Maintenance Coefficient (Cm) indicate that 260 m² is required to maintain each meter of perennial channel. The high values of drainage density (Dd = 3.35 km.km -2 ) and sinuosity index (Is = 0.95) indicate that drainage channels in the area are rectilinear, thus suggesting the occurrence of a high surface runoff associated with high dissection. The analysis of land use and occupation revealed that, from the seven types of vegetation cover, the dominant cover in the Areal basin is 0.756 km 2 (40%) constituted of pasture, while forest represents 0.580 km 2 (31%), 0.321 km 2 (17%) of the land cover is constituted of degraded forest. In terms of conservation, the Areal basin is conserved because, besides being located in the environmental preservation area of the Una River Basin, it is located at the meeting of two ecological corridors and is occupied by only 8 families of rural producers. On the other hand, the creation of approximately 120 head of cattle in the upper part of the basin and the existence of gully erosion of the order of 0.018 km 2 (1%) of the basin area, which led to increased runoff and sediment concentration in the flat areas marginal to the creek of Areal. Based on morphometric analysis, it was concluded that: Areal watershed presents high capacity to form new watercourses and their relief characteristics, with low sinuosity channels and high values of altimetric amplitude, channel gradient, and density. Drainage, allied to the existence of erosive processes, favors sediment flow and transport. Conservation actions are required to control erosion.

The changes in environmental factors in a hydrographic basin, mainly in the urban environment, enable different scenarios than the change of parameters in climatic, physical, political, and socioeconomic factors. Those changes may have immediate effects on indigenous populations, often making them vulnerable to the risk of flooding. This article evaluates the vulnerability to flooding in the municipality of São José dos Campos, State of São Paulo, Brazil using multicriteria analysis and geoprocessing techniques. Quantum GIS (QGIS) was used in the manipulation and processing of vector and matrix data related to the terrain slope, hydrography, geotechnics, and data history of flooding (2009 - 2018) in São José dos Campos. The hierarchy and criteria weighting processes were carried out, as well as the zoning of areas at risk of flooding. Thus, it was found that 23.81% and 2.17% of the municipal territory has high and very high susceptibility to flooding. It can be concluded that the combined use of multicriteria analysis and geoprocessing is an effective contribution to assist the management of public policies in order to obtain more assertive decisions in the prevention or reduction of flood risks.

The mapping of the Permanent Preservation Areas (PPAs) of the municipal district of Santo Antônio do Pinhal, SP, located in an area of great real estate interest in the Mantiqueira Moutains of São Paulo, neighbor of the touristic municipal district of Campos de Jordão, SP, became necessary. The need for producing cartographic documents is to support environmental authorities to establish plans for the preservation of these areas, especially the Permanent Preservation Areas (PPA) established by the Law 4,771/65 and regulated by the

A determinação de áreas prioritárias para o restabelecimento da cobertura florestal nativa em bacias hidrográficas se constitui numa necessidade diretamente associada à probabilidade de sucesso efetivo na recuperação e na maximização dos recursos necessários. No entanto, para atender a essa finalidade, a complexidade no tratamento e o volume de dados ambientais espacializados necessários requerem um aparato tecnológico capaz de processar dados de apoio à análise multicriterial como ferramenta de suporte à decisão, no estado da arte das geotecnologias aplicáveis. Nesse contexto, o presente trabalho desenvolvido para uma área de 476 km² correspondente à área da bacia hidrográfica do rio Una, no município de Taubaté, SP, baseou-se em uma análise multicriterial usando classificação contínua e na técnica de comparação pareada AHP (Analytical Hierarchy Process), incorporados ao SIG completo denominado SPRING (Sistema de Processamento de Informações Georreferenciadas), para a geração de um mapa de áreas prioritárias para o restabelecimento da cobertura florestal nativa na bacia. Os resultados obtidos com base na análise dos fatores: valor da terra nua; distância de fragmentos; classes de capacidade de uso do solo; áreas de preservação permanente (APPs); dentre outros, revelaram uma grande área, correspondente a 26,6% da área da bacia, classificada como "Prioridade Extrema". Isso indica a necessidade imediata de recuperação ambiental da bacia uma vez que ela é manancial para o abastecimento de Taubaté, SP. Os resultados permitem de forma prática subsidiar a tomada de decisão na alocação de recursos e projetos dessa natureza nessas áreas prioritárias.