Work object – Vyžuona river, which has 26 km lenght, is left affluent of Šventoji river, belongs to subbasin of Šventoji river and runs from northeast to southwest of Lithuania. Work aim – identify water quality and bounded with it live organisms of Vyžuona river. Work tasks – analyse physical-chemical water parameters of Vyžuona river, identify varietal composition of organisms, define and evaluate contamination of river objects. Work results – After the reasearch was made there was defined that Vyžuona river in Utena town (1 km from Krašuona river and Vieša river junction) belongs to average contaminated rivers category measuring by parameters of water quality: common nitrogen quantity 1.9 times exceeds permissible quotas, 68.6 % of common nitrogen is composed of nitrate nitrogen, BDS7 quantity 2,7 times exceeds the LDK, concentration of phosphates 2.3 times exceeded permissible quotas. Krašuona river and Vieša river runs trough private houses section, which has no central sewer and that is the reason why mentioned rivers are bearing domestic contaminants into Vyžuona river. According to 2004-2006 data below the outlet from drain mechanism of UAB „Utenos vandenys“ refinement system there was found concentration of phosphorus which averagely 1,75 times, common nitrogen 1,1 times and BDS7 1,7 times less in comparison with river part in centre of Utena town above UAB „Utenos vandenys“. That may be explained by UAB „Utenos vandeys“ affect, which drains large amount of enough... [to full text]

The master student’s work analyzes water quality of the river Tatula above and below the tributary Juodupė saturated with municipal wastewater of Biržai town. Study object. The river Tatula is a 66.2-km long right tributary of the Mūša. The river Tatula belongs to the river Lielupė basin located in northern part of Lithuania. The Tatula is flowing via cultivated karst region. Objective of work: to determine the changes in water quality of the river Tatula within the period of 1994-2004, when old wastewater treatment facilities were functioning in Biržai town and the new facilities started working in 2003. Study methodology. The study is based on the data of water quality measurements conducted by the United Research Center of the Ministry of Environment as well as additional data collected by the author in 2003-2004 in the river Tatula above the Juodupė inflow (distance from the outlet 18.8 km; basin area 191.4 km2) and below the tributary (distance from the outlet 17.5 km, basin area 283 km2). To estimate the changes in water quality during the study period, 26 parameters indicating water quality were analyzed; the changes in concentrations of nitrogen and phosphorus were considered as topical issues. Water quality was estimated on the basis of river water classification. Water samples were analyzed in the laboratory of wastewater treatment facilities of Biržai town. Study results. As the study results have shown, according to all water quality parameters the stretch of... [to full text]

This work aims to evaluate in time and space the quality of the lake water of the Miranda hydroelectric power plant by means of physicochemical and bacteriologic analyses. The collections of samples were made in two distinct seasons of the year : dry and rainy in the years of 2003, 2004, 2005, 2006 and 2007. Results of the analyses indicated considerable variations in the biochemical demand of oxygen, of the chemical demand of oxygen, of the dissolved oxygen, of oils and grease, of total dissolved solid, of the transparency, of the turbidness and of the bacteria presence of the coliform group. The values of the samples were interpreted in function of the limits of acceptance established by the Resolut ion 357 of CONAMA (2005). To help in the understanding of the results of the physicochemical and bacteriologic analyses, the area of study was mapped in what concerns the usage and occupation of the lands. This mapping identif ied the presence of 70,55% of antropic usage, 26,77% of natural vegetation cover and 2,68% occupied by water bodies. The map with dist ribution of the Water Quality Indices (WQI) points out that the major varies f rom great (79< WQI<100) to regular (36< WQI<51). The evaluation of physical, chemical and biological variations of the water of Miranda Lake allied to techniques of geoprocessing, allowed a better knowledge of the envi ronmental condi tions of the study area, and the results obtained can be used as sources of primary data to promote the planning and local and regional envi ronmental gestalt. / Este trabalho possui o objetivo de avaliar temporal e espacialmente a qualidade da água do lago da Usina Hidrelétrica de Miranda por meio de análises f ísico-químicas e bacteriológicas. As coletas de amostras de água foram realizadas em duas estações distintas do ano: seca e chuvosa nos anos de 2003, 2004, 2005, 2006 e 2007. Resultados das análises realizadas indicaram variações consideráveis dos valores da Demanda Bioquímica de Oxigênio, da Demanda Química de Oxigênio, do Oxigênio Dissolvido, de Óleos e Graxas, de Sólidos Dissolvidos Totais, da Transparência, da Turbidez e da presença de bactérias do grupo Coliformes. Os valores dos ensaios foram interpretados em função dos limites de aceitação individuais para cada substância em cada classe, visando a atendimento aos padrões de qualidade das águas estabelecidos pela Resolução nº 357 do CONAMA (2005). Para auxiliar no entendimento dos resultados das análises físico-químicas e bacteriológicas, a área de estudo foi mapeada quanto ao uso e ocupação das terras. Este mapeamento identificou a presença de 70,55 % do uso antrópico, 26,77% de cobertura vegetal natural e 2,68 % ocupada pelos corpos d água. O mapa com distribuição do Índice de Qualidade da Água (IQA) most ra que a maioria oscila entre ótimo (79>IQA100) e regular (36>IQA51). A avaliação de variáveis f ísicas, químicas e biológicas da água do lago de Miranda, aliada a técnicas de geoprocessamento, propiciaram um melhor conhecimento das condições ambientais da área de estudo, e os resultados obtidos podem ser utilizados como fontes de dados primários para promover o planejamento e gestão ambiental local e regional. / Mestre em Geografia