O objetivo deste trabalho foi avaliar a qualidade das águas superficiais e subterrâneas em microbacias hidrográficas caracterizadas por diferentes coberturas do solo: pastagem, floresta e cafeeiro. Foi desenvolvido um índice de qualidade de água utilizando a análise de componentes principais, que proporcionou a redução das 13 características de qualidade em duas componentes, que explicaram 91,2% da variância total. As águas superficiais e subterrâneas das microbacias foram adequadas ao consumo humano, após tratamento convencional, ao longo de todo o período estudado, exceto a água subterrânea da microbacia coberta com pastagem no período de estiagem.<br>The objective of this work was to evaluate the quality of surface water and groundwater in watersheds characterized by different vegetal cover: pasture, forest and coffee crops. It was developed a water quality index by using the analysis of the main components, which provided the reduction of 13 quality features into two components that explained 91.2% of the total variance. Surface water and groundwater of the watersheds were suitable for human consumption after conventional treatment over the studied period, except the groundwater of watershed covered with pasture in the dry season.

Abstract The increase in population in the Utcubamba River basin without the corresponding implementation of wastewater treatment systems by the authorities has led to a decrease in water quality, which constitutes a threat to public health and the ecosystem preservation. The objective of this work was to reduce the data collected in large hydrographic basins, both at the sampling stations level and at the level of variables. Sampling was carried out at 43 sites located in the main channel and major tributaries, and their physicochemical and microbiological quality were analyzed through the determination of 19 variables during three different seasons (early rains, rainfall and drought). Multivariate statistical methods (correlation analysis, principal component analysis and cluster analysis) were applied to find the cause of natural or anthropogenic sources of pollution and its distribution in the basin. The results show that the main parameters that spatially affect the basin are a result of high concentrations of bacteria and chemical compounds such as nitrites, phosphates and ammonium. Finally, the use of multivariate methodologies to analyze the obtained results allows to reduce the number of variables as well as sampling stations for future evaluations. | Resumen El aumento de la población a lo largo de la cuenca del río Utcubamba, sin la correspondiente implementación de sistemas de tratamiento de aguas residuales por parte de las autoridades, ha provocado la disminución en la calidad del agua, lo que constituye una amenaza para la salud pública y la preservación del ecosistema. El objetivo de este trabajo es disminuir el conjunto de datos recogidos en grandes cuencas hidrográficas tanto a nivel de estaciones de muestreo como a nivel de variables. Se realizaron muestreos en 43 estaciones situadas en el cauce principal y afluentes más importantes, y se analizó su calidad fisicoquímica y microbiológica a través de la determinación de 19 variables en tres campañas distintas (lluvias tempranas, lluvias y seca). Se aplicaron métodos estadísticos multivariantes (análisis de correlación, análisis de componentes principales y análisis cluster), para encontrar el origen de las fuentes de contaminación, naturales o antrópicas, y la distribución de la misma. Los resultados obtenidos muestran que los principales parámetros que afectan espacialmente la cuenca derivan de las altas concentraciones de bacterias y de compuestos químicos, como nitritos, fosfatos y amonio. Por último, el uso de metodologías multivariantes en el análisis de los resultados obtenidos permite disminuir el número tanto de variables como de estaciones de muestreo en futuras evaluaciones.

Uruguay has a dense hydrographic network, nevertheless the knowledge of the aquatic macroinvertebrate community is still lacking. In recent decades afforestation with exotic species has increased which has produced changes in riparian vegetation of some rivers. The aim of this research was to determine the composition and trophic structure of macroinvertebrate community and its relationship to some physicochemical parameters in eight streams where the native forest is still well preserved and provide the basis for future studies. Samples were collected from December 2006 to December 2007. Temperature, dissolved oxygen, pH and conductivity were measured in situ. Taxonomic composition and abundance were determined, a principal component analysis and a canonical correspondence analysis were carried out with the physico-chemical and biological parameters. The alpha diversity was calculated using the Shannon-Weaver (H'), dominance of Simpson (D) and Pielou evenness indexes (J'). Beta diversity was determined employing similarity index of Bray-Curtis. A total of 1 291 specimens belonging 92 taxa were recorded. The most abundant taxa were Ephemeroptera (36%), Amphipoda (17%) and Coleoptera (12%). The streams show high diversity and low dominance. Conductivity, pH, and temperature were the main factors in determining the macroinvertebrate distribution and composition.

RESUMO O objetivo deste estudo foi avaliar a qualidade da água e identificar os grupos de poluição presentes no médio Rio Pomba, por meio de técnica estatística multivariada. Duas campanhas no período de out/2008 a jan/2009 foram realizadas em nove pontos georreferenciados, localizados ao longo do médio Rio Pomba, compreendendo a análise de 18 variáveis de qualidade de água. A técnica estatística multivariada por meio da aplicação da análise fatorial/análise de componentes principais promoveu a redução no número de variáveis de qualidade de água, uma vez que o melhor comportamento das variáveis ocorreu com a inclusão de 15 das 18 variáveis analisadas. Pelo emprego da análise fatorial/análise de componentes principais identificou-se que o melhor comportamento das variáveis de qualidade das águas do médio Rio Pomba foi aquele composto por três fatores, explicando 74,30% da variância total. As variações na qualidade da água no médio Rio Pomba foram definidas por um grupo de nutrientes associado ao esgoto doméstico e à poluição difusa; por um grupo orgânico, causado pelo lançamento de esgoto doméstico no curso de água e por um grupo de sólidos em suspensão, expressando o processo de erosão hídrica na bacia. | 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.

Este trabajo presenta la construcción de un indice de calidad del agua (ICA) como una herramienta de valoración, propone una escala de clasificación de 0 a 100, que permite establecer de una forma rápida la calidad de los cuerpos de agua de los ecosistemas de humedal de Bogota; este indice considera diez parámetros relacionados con la conservación de flora y fauna, parámetros que fueron seleccionados teniendo en cuenta la normativa ambiental nacional (decreto 1076 de 2015). Como herramienta de análisis se tomaron los registros históricos de monitoreos de calidad del agua de los humedales, además se realizó un análisis factorial de componentes principales en la selección de parámetros para evidenciar el nivel de correlación entre las variables y así escoger aquellas que aportaran más información al modelo. El índice es calculado por medio de la raíz cuadrada del promedio armónico no ponderado; esta expresión fue seleccionada luego de ser comparada con otras y evaluar la sensibilidad de esta a los cambios individuales de las variables. Finalmente, se entrega una matriz de Excel en la cual se alimentan los datos mediante una condición de entrada que permite la determinación rápida del índice (ICAHUMB) permitiendo valorar la calidad ambienal de los humedales. | This paper presents the construction of a water quality index (ICA) as an assessment tool proposes a rating scale of 0 to 100, which allows for a quick way the quality of the water bodies of wetland ecosystems from Bogota; This index considers ten parameters related to the conservation of flora and fauna parameters were selected based on national environmental standards (Decree 1076 of 2015). Keil historical records of monitoring water quality of wetlands were taken, plus a factorial principal component analysis was performed on the selection of parameters to demonstrate the level of correlation between the variables and so choose those that provide more information the model. The index is calculated by the square root of the average unweighted harmonic; this expression was selected after being compared and evaluate the sensitivity of individual changes in the variables. Finally, a matrix of Excel in which the data is fed through an input condition that enables rapid determination of the index (ICAHUMB) allowing assess the quality of wetlands ambienal delivered | Ingeniero Ambiental | Pregrado

O objetivo deste trabalho foi avaliar a qualidade das águas superficiais e subterrâneas em microbacias hidrográficas caracterizadas por diferentes coberturas do solo: pastagem, floresta e cafeeiro. Foi desenvolvido um índice de qualidade de água utilizando a análise de componentes principais, que proporcionou a redução das 13 características de qualidade em duas componentes, que explicaram 91,2% da variância total. As águas superficiais e subterrâneas das microbacias foram adequadas ao consumo humano, após tratamento convencional, ao longo de todo o período estudado, exceto a água subterrânea da microbacia coberta com pastagem no período de estiagem. | The objective of this work was to evaluate the quality of surface water and groundwater in watersheds characterized by different vegetal cover: pasture, forest and coffee crops. It was developed a water quality index by using the analysis of the main components, which provided the reduction of 13 quality features into two components that explained 91.2% of the total variance. Surface water and groundwater of the watersheds were suitable for human consumption after conventional treatment over the studied period, except the groundwater of watershed covered with pasture in the dry season.

Drinking water monitoring plans are important to characterize both treated and untreated water used for drinking purposes. Access to drinking water increased in recent years as a response to the Millennium Development Goals set for 2015. The new Sustainable Development Goals aim to ensure universal access to safe drinking water by 2030. Within the framework of these global goals, it is crucial to monitor local drinking water systems. In this paper, treated and untreated water from different sources currently consumed in a specific town in Salta, northern Argentina, was thoroughly assessed. Monitoring extended along several seasons and included the physical, chemical and microbiological variables recommended by the Argentine Food Code. On the one hand, treated water mostly complies with these standards, with some non-compliances detected during the rainy season. Untreated water, on the other hand, never meets microbiological standards and is unfit for human consumption. Monitoring seems essential to detect anomalies and help guarantee a constant provision of safe drinking water. New treatment plants are urgently needed to expand the water grid to the entire population.

Investigation of surface water and groundwater interaction (SW–GW interaction) provides basic information for regional water-resource protection, management, and development. In this survey of a 10-km-wide area along both sides of the Songhua River, northeast China, the hydrogeochemical responses to different SW–GW interactions were studied. Three types of SW–GW interactions were identified—“recharge”, “discharge”, and “flow-through”—according to the hydraulic connection between the surface water and groundwater. The single factor index, principal component analysis, and hierarchical cluster analysis of the hydrogeochemistry and pollutant data illuminated the hydrogeochemical response to the various SW–GW interactions. Clear SW–GW interactions along the Songhua River were revealed: (1) upstream in the study area, groundwater usually discharges into the surface water, (2) groundwater is recharged by surface water downstream, and (3) discharge and flow-through coexist in between. Statistical analysis indicated that the degree of hydrogeochemical response in different types of hydraulic connection varied, being clear in recharge and flow-through modes, and less obvious in discharge mode. During the interaction process, dilution, adsorption, redox reactions, nitrification, denitrification, and biodegradation contributed to the pollutant concentration and affected hydrogeochemical response in the hyporheic zone.

The mining industry, especially coal mining, may severely affect the spatial and temporal evolution of groundwater. To provide a potential model outlining the hydrogeochemical evolution of groundwater as influenced by coal mining, a multi-layer groundwater system in a coal mining area was investigated. A total of 76 groundwater samples were collected between 1964 and 2018 for hydrogeochemical analysis from boreholes, underground tunnels, and surface pits at Xinglongzhuang Coal Mine in China. Hierarchical cluster analysis and principal component analysis were used to classify four significant groundwater zones and two principal components. The results showed that mining may have caused the rock strata to sink, obstructing the path linking the Permian and lower Quaternary aquifers, and resulting in intensified ion exchange in the lower Quaternary aquifer. The concentrations of Na⁺ and Ca²⁺ in the groundwater from the lower Quaternary aquifer changed over the studied period (~54 years). The gradual increase of Na⁺ and decrease of Ca²⁺ concentration verified the action of cation exchange. The four main aquifers had relatively independent hydrogeochemistry, suggesting that the hydraulic conductivity of the natural faults is weak and the sealing properties of hydrogeological drill holes in the coal field are good. Analysis of 26 heavy metals in the mine drainage water showed that there is only minor pollution after the water has been simply treated. These data analysis methods and results could be useful in areas with long-term mining to interpret the evolution of groundwater and to promote groundwater quality management.

The processes that affect water chemistry as the water flows from recharge areas through breccia-pipe uranium deposits in the Grand Canyon region of the southwestern United States are not well understood. Pigeon Spring had elevated uranium in 1982 (44 μg/L), compared to other perched springs (2.7–18 μg/L), prior to mining operations at the nearby Pigeon Mine. Perched groundwater springs in an area around the Pigeon Mine were sampled between 2009 and 2015 and compared with material from the Pigeon Mine to better understand the geochemistry and hydrology of the area. Two general groups of perched groundwater springs were identified from this study; one group is characterized by calcium sulfate type water, low uranium activity ratio ²³⁴U/²³⁸U (UAR) values, and a mixture of water with some component of modern water, and the other group by calcium-magnesium sulfate type water, higher UAR values, and radiocarbon ages indicating recharge on the order of several thousand years ago. Multivariate statistical principal components analysis of Pigeon Mine and spring samples indicate Cu, Pb, As, Mn, and Cd concentrations distinguished mining-related leachates from perched groundwater springs. The groundwater potentiometric surface indicates that perched groundwater at Pigeon Mine would likely flow toward the northwest away from Pigeon Spring. The geochemical analysis of the water, sediment and rock samples collected from the Snake Gulch area indicate that the elevated uranium at Pigeon Spring is likely related to a natural source of uranium upgradient from the spring and not likely related to the Pigeon Mine.