Celso Bandeira de Melo Ribeiro

Aplicação da análise estatística multivariada no estudo da qualidade da água do Rio Pomba, MG

ABSTRACT The aim of this study was to evaluate the water quality and identify groups of pollution in the Middle Pomba River through multivariate statistical technique. There were two campaigns from Oct/2008 to Jan/2009 in nine geo-referenced points along the Middle Pomba River including the analysis of 18 variables of water quality. The multivariate statistical technique, through the application of factor analysis/principal component analysis, caused a decrease in the number of variables of water quality, since the best performance of the variables occurred with the inclusion of 15 of the 18 variables. By the use of factor analysis/principal components analysis, it was found that the best behavior of the variables of the water quality of the Middle Pomba River waters was the one composed of three factors, explaining 74.30% of the total variance. Changes in water quality of the Middle Pomba River were defined by a group of nutrients associated with sewage and diffused pollution; for an organic group, caused by untreated sewage in the water stream, and by a group of suspended solids, expressing the process of water erosion in the basin.

Desenvolvimento e validação de equação para determinação do coeficiente de dispersão longitudinal em rios de médio porte

In this paper, an equation has been developed to estimate the longitudinal dispersion coefficient (DL) in medium-sized rivers, with flow between 16.20 and 98 m3s-1, from experimental tests using fluorescent tracers. The equation was deduced by dimensional analysis and adjusted to the field data by the multiple linear regression technique. Thereafter, the validation of the equation was performed by testing it in another database, which is different from the one it had been developed for, with flow between 19.57 and 48.54 m3s-1. Additionally, the performance of four other empirical equations was compared for DL prediction using three comparative methods. The developed equation showed appropriate statistical adjustment and good result, with better overall performance when compared with other equations proposed in literature.

Sistema de alerta com base em estudo teórico-experimental de dispersão de poluentes solúveis em rios

Information about capacity of transport and dispersion of soluble pollutants in natural streams are important in the management of water resources, especially in planning preventive measures to minimize the problems caused by accidental or intentional waste, in public health and economic activities that depend on the use of water. Considering this importance, this study aimed to develop a warning system for rivers, based on experimental techniques using tracers and analytical equations of one-dimensional transport of soluble pollutants conservative, to subsidizing the decision-making in the management of water resources. The system was development in JAVA programming language and MySQL database can predict the travel time of pollutants clouds from a point of eviction and graphically displays the temporal distribution of concentrations of passage clouds, in a particular location, downstream from the point of its launch.

Estudo da poluição pontual e difusa na bacia de contribuição do reservatório da usina hidrelétrica de Funil utilizando modelagem espacialmente distribuída em Sistema de Informação Geográfica

Este estudo avaliou o potencial poluidor da bacia de contribuicao do reservatorio de Funil (BCRF), localizado na bacia hidrografica do rio Paraiba do Sul, considerando a geracao da carga de nutrientes, nitrogenio (N) e fosforo (P), por fontes pontuais e difusas, a partir de uma modelagem distribuida utilizando Sistema de Informacao Geografica (SIG). As cargas e concentracoes medias anuais desses nutrientes foram geradas a partir do acoplamento de equacoes empiricas, em SIG, considerando informacoes espaciais de uso e cobertura do solo, populacao residente na bacia e vazao media anual de longo periodo, obtida por equacoes do tipo chuva vazao. Os resultados indicaram que 80% da carga total de nitrogenio foram provenientes de fontes pontuais e 20% de fontes difusas, enquanto que, da carga total de fosforo, 89,1% foram originadas de fontes pontuais e 10,9% de fontes difusas. As concentracoes de nutrientes estimadas pelo modelo empirico apresentaram bons ajustes em relacao aos valores observados de fosforo e de nitrogenio no rio Paraiba do Sul, com R²=0,96 (p<0,01) e R²=0,70 (p<0,01), respectivamente. Dessa forma, o modelo foi capaz de detectar, de forma significativa, a tendencia das variacoes nas concentracoes de nutrientes ao longo de diferentes trechos da BCRF.

Instream flow and the Brazilian legal framework

generation, among others, result in environmental degradation and conflicts over water use, especially in relation to natural aquatic ecosystems conservation. The recognition of hydrological changes caused by such demands and its consequent environmental degradation on a global scale led to ecohydrology studies, in other words, the functional interrelations between hydrology and biota, using aquatic ecosystems as sustainable management tool of water resources. In this context, the aim of this chapter is to present some procedures to determine environmental flows, focusing on those with ecological approach effectively subsidized by habitat and holistic methodologies. We hope to draw a parallel with the instream flow studies in Brazil and identify the gap between the state of the art in the world and in the Brazilian legal framework on the subject. Although Brazilian law explains the adequacy of water resources management to biotic diversity and its integration with environmental management, this still relies on a conceptual basis of remaining flows, associated with quantitative hydrological methods, wich are precursor of ecological and environmental methodologies. In addition, the experimental work, although scarce, has shown that the instream flow Revista Brasileira de Geografia Física V. 09 N. 01 (2016) 091-109.

Erosão Potencial Laminar Hídrica em um Latossolo Vermelho Amarelo sob Três Formas de Cultivo (Water Layer Erosion Potential in an Oxisol Under Three Cultivation Forms)

O manejo e a cobertura influenciam na erosao do solo. Os objetivos desse experimento foram determinar as perdas de solo e agua e os fatores da Equacao Universal de Perda de Solo (EUPS) em condicoes de chuva natural em um Latossolo Vermelho Amarelo com declividade media de 20%. Foram avaliados tres tratamentos relativos ao manejo do solo e da vegetacao de cobertura. Para cada tratamento foram instaladas duas parcelas. As parcelas apresentaram tratamentos diferenciados, correspondentes a duas formas de cobertura do solo e um tratamento com solo descoberto: solo exposto, pastagem de Brachiaria decumbens cv. Basilisk e area manejada com o consorcio milho e braquiaria (integracao lavoura-pecuaria). O valor considerado para o fator (P) foi de 0,5. As perdas de solo e agua foram: 117,79 t ha -1 e 2.372,230 L ha -1 ; 94,68 t ha -1 e 2.086,570 L ha -1 ; 20,50 t ha -1 e 1.687,135 L ha -1 para o solo exposto, braquiaria e braquiaria com milho, respectivamente. O fator erosividade (R) foi de 7.589 MJ mm ha -1 h -1 ; o de erodibilidade (K) 0,009 t ha MJ -1 mm -1 , enquanto os valores do fator (C) foram de 1, 0,54 e 0,15 para os tratamentos solo exposto, braquiaria pura e para o consorcio milho com braquiaria, respectivamente. Dessa forma, concluiu-se que, o consorcio milho com braquiaria reduziu as perdas de solo e agua em relacao a parcela com solo exposto e a parcela apenas com braquiaria. ABSTRACT The erosion is influenced by the management and soil cover. The aim were to determinate the soil and water losses and the factors of the Universal Soil Loss Equation (USLE) in natural rainfall conditions under Oxisol with 20% slope. Three managements were evaluated: soil without plant cultivation, Brachiaria decumbens signal cultivation and crop-pasture integrated system. In each management, two plots were implemented. The assumed value of the factor P (practice factor) was 0,5. The soil and water losses were of 117,79 t ha -1 and 2.372,230 L ha -1 , 94,68 t ha -1 and 2.086,570 L ha -1 , 20,50 t ha -1 and 1.687,135 L ha -1 for the soil without plant cultivation, B. decumbens signal cultivation and maize with B. decumbens consortium, respectively. The rainfall and runoff factor (R) was 7.589 MJ mm ha -1 h -1 and the soil erodibility factor (K) was 0,009 t ha MJ 1 mm -1 . The values of cover and management factor (C) were of 1, 0,54 e 0,15 for the soil without plant cultivation, B. decumbens signal cultivation and maize with B. decumbens consortium, respectively. Thus, it was concluded that maize with B. decumbens consortium reduced losses of soil and water compared to soil without plant cultivation plot and B. decumbens signal cultivation plot. Keywords: crop-pasture integrated system, runoff, universal soil loss equation.