Abstract: The accelerated and disorganized deforestation in Central Brazil and the transformation of these natural ecosystems into crop land or pastures, without adequate technologies, resulted in irrecoverable damages to the environment, especially with respect to water and soil conservation, with particular mention to compactation. As a consequence, the soil intake rate decreased and surface runoff increased, thus causing laminar erosion, low soil quality, silting up of rivers, floods and decreased sustainability of family properties. With the objective of reverting this scenario, a demonstrative unit was implemented in Sete Lagoas MG, in 1995, in a property of 70 ha, where 30 micro-cachments ("barraginhas") were built to contain surface runoff damages.These micro-cachtments also retain pollution sources carried by the waters and favor the recharge of good quality water tables, by means of improving soil intake rate, recovering water sources and alleviating droughts. Due to the success of this demonstration unit, by means of field visits by farmers, NGO´s and publication of articles in journals and national/international congresses, a decision was taken to extend the experience and build 960 low-cost micro-catchments, in 1998, in 60 small properties covering all the micro-basin of the Paiol stream, in the village/community of Estiva, Sete Lagoas county. That was only possible because of the active participation of small farmers in the indication of existing degraded sites and the support provided in terms of food and lodging for the working teams As a result, it is now possible to hear the farmers testimonials on the effects observed in elevation of water tables observed in their domestic reservoirs ("cisternas"), better utilization of the water and drought alleviation, that have increased their yields.

Increased human activities are threatening watershed landscapes and water quality monitoring and multiscale analysis have become essential tools for water resource management. In order to evaluate the influence of land use on water quality at different spatial scales. Twelve low-order streams were selected in which limnological samplings (physical, chemical and biological) were carried out during the dry season. The water quality index was used, based on the quality standards of Canada and Brazil. The percentage of land use was measured at local scale and water network. The environmental variables were summarized through Principal Component Analysis (PCA) and subsequently used in the construction of Linear Models (lm) for each axis resulting from the PCA, using the percentage of land use classes and land slope. The presence of contamination by Lead, Chromium, Copper, Nitrogen and Escherichia coli was verified. It was found that the Canadian Water Quality Guidelines for the Protection of Aquatic Life (CWQG-PAL) were more effective in protecting aquatic ecosystems than the National Council for the Environment Resolution No. 357/2005 (CONAMA 357/2005), due to its constant, more rigorous and sensitive monitoring. Agricultural activities and those inherent to urban areas were the main responsible for the degradation of water quality. The negative impact of agriculture was observed both on a local scale and on the water network, while urban areas had a negative effect only on the water network scale. It was also found that forests on a local scale are associated with improved water quality. It emphasizes the importance of the multiscale approach in the management of watersheds and in public policies, which should consider not only forest preservation on a local scale, but also human activities throughout the watershed. It is recommended the need for a reformulation of CONAMA Resolution No. 357/2005 with a methodology applied to conservationism and holistic, as well as the importance of public policies and changes in the law of the Brazilian Forest Code on areas of permanent preservation. | O aumento das atividades humanas ameaça as paisagens das bacias hidrográficas e o monitoramento da qualidade da água e as análises multiescala têm se tornado ferramentas essenciais para a gestão dos recursos hídricos. Com o objetivo de avaliar a influência do uso da terra na qualidade da água em diferentes escalas espaciais. Foram selecionados 12 riachos de baixa ordem nos quais foram realizadas amostragens limnológicas (físicas, químicas e biológicas) durante o período de estiagem. Utilizou-se o índice de qualidade da água, com base nos padrões de qualidade do Canadá e Brasil. Mediu-se a porcentagem de uso da terra em escala local e rede hídrica. As variáveis ambientais foram sumarizadas por meio da Análise de Componentes Principais (PCA) e posteriormente utilizadas na construção de Modelos Lineares (lm) para cada eixo resultante da PCA, utilizando a porcentagem das classes de uso da terra e declividade do terreno. Constatou-se a presença de contaminação por Chumbo, Cromo, Cobre, Nitrogênio e Escherichia coli. Constatou-se que as Diretrizes Canadenses de Qualidade da Água para a Proteção da Vida Aquática (CWQG-PAL) foram mais efetivas na proteção dos ecossistemas aquáticos do que a Resolução do Conselho Nacional do Meio Ambiente N° 357/2005 (CONAMA 357/2005), devido ao seu monitoramento constante, mais rigoroso e sensível. As atividades agropecuárias e aquelas inerentes às áreas urbanas foram as principais responsáveis pela degradação da qualidade da água. Observou-se o impacto negativo da agropecuária tanto em escala local quanto na rede hídrica, enquanto as áreas urbanas tiveram o efeito negativo somente na escala de rede hídrica. Constatou-se também que as florestas em escala local estão associadas a melhoria na qualidade da água. Ressalta-se a importância da abordagem multiescala na gestão de bacias hidrográficas e nas políticas públicas, que deve considerar não apenas a preservação florestal em escala local, mas também as atividades humanas em toda a bacia hidrográfica. Recomenda-se a necessidade de uma reformulação na Resolução CONAMA Nº 357/2005 com uma metodologia aplicada ao conservacionismo e holística, bem como, a importância de políticas públicas e mudanças na lei do Código Florestal Brasileiro sobre as áreas de preservação permanente. | Masters

The effects of swine wastewater on atrazine dissipation and formation of bound residues in subtropical clay soil were investigated in this study. The experiment was carried out in laboratory, under room conditions, where samples of Rhodic Hapludox soil received 168.61 mg kg-1 of atrazine and were incubated for 60 days in the following treatments: T1 (sterilized soil + swine wastewater), T2 (sterilized soil + distilled water), T3 (Non sterilized soil + swine wastewater) and T4 (Non sterilized soil + distilled water). The extractable residues and bound residues of atrazine were extracted and analyzed by high performance liquid chromatography. The results showed no effect of swine wastewater on atrazine dissipation. However, the addition of swine wastewater favored the increase of bound residues, which can increase the persistence of atrazine in the environment and reduce its bioavailability.<br>Os efeitos da aplicação de água residuária da suinocultura (ARS) na dissipação de atrazina e formação de resíduos ligados em solo subtropical argiloso foram investigados neste trabalho. O experimento foi conduzido em laboratório, sob condições controladas, onde amostras de Latossolo Vermelho distroférrico receberam a aplicação de 168,61 mg kg-1 de atrazina e foram incubadas durante 60 dias, de acordo com os seguintes tratamentos: T1 (Solo esterilizado + ARS); T2 (Solo esterilizado + água destilada); T3 (Solo não esterilizado + ARS), e T4 (Solo não esterilizado + água destilada). Os resíduos extraíveis de atrazina e resíduos ligados foram extraídos e analisados por cromatografía líquida de alta eficiência. Os resultados mostraram que não houve efeito da aplicação de ARS na dissipação de atrazina. Entretanto, a adição de ARS ao solo favoreceu o aumento da formação de resíduos ligados, o que pode aumentar a persistência da atrazina no ambiente e diminuir sua biodisponibilidade.