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This paper presents the results of polychlorinated biphenyls (PCBs) determination in sediments from different sites of the Odra River and its tributaries, collected in 1998-2002. It was found that concentrations of PCBs varied significantly. The results of individual congeners show that contents of PCBs 180 and 138 were the highest in the sediments investigated. For better identification of places most polluted by PCBs, PCB contents on TOC (total organic carbon) basis in surface sediments are presented.
The subject of the study were changes in land use over the last 400 years, including forest areas. The research covered the area, the range of which is determined by the basins of three small left-bank tributaries of the Wieprza River and its direct catchments (Northern Poland). The analysis included selected historical sources and, above all, maps issued in the years 1618-2008. It was found that in the studied area the border between forest and non-forest areas was established in the Middle Ages and subsequent changes in its course were of evolutionary nature. Until the midnineteenth century there was significant decline in forest area, which was related to the acquisition of areas mainly for arable fields as well as meadows and pastures. Subsequent changes of forest areas, studied for periods 1836-1934 and 1934-2008 were relatively small, but they were accompanied by significant modifications of the forest species composition. Relatively the biggest changes in the last distinguished period included built-up areas with orchards, where a decrease in occupied areas of almost 25% was noted.
The study dealt with the bottom sediments from the Narew River in the section Bondary-Tykocin 18 tributaries in the catchment of the upper Narew. Samples were collected in summer (August) and autumn (October) 2005 from the surface layer of bottom sediments in the shore zone. Determinations of organic carbon were performed on a TOC 1200 analyzer (Thermo Euroglas). The bottom sediments collected from the upper Narew contained less organic carbon, which resulted from intensive mineralization. Sediments from the small rivers were most abundant in organic carbon. These rivers are characterized by a low flow rate and, in most cases, they are overgrown by water plants. The organic carbon contents were highly varied between the sampling points. Positive linear correlation was found between combustion loss and organic carbon content.
In the paper, the effects of differences in land use of a catchment and settlements on the variability of heavy metals concentrations (Zn, Pb, Cu, Cd, Ni) in the Narew River and some of its tributaries such as the Biebrza, upper Narew, Pisa, Omulew and Rozoga rivers were studied. The investigations continued from 1997 to 2002. The areas dewatered by the watercources differ considerably in terms of environmental features (forests, wetlands, bogs and water reservoirs), land use (arable lands, grasslands) and population (man-made areas). The total catchment of the Narew River at the cross-section in Zamski Kościelne was also taken into account. The urban areas make up from 0.5% of the Rozoga River to 2.5% of the upper Narew catchment. Water samples were collected quarterly (April, July, October and January) from four study sites located near the river mouth and were analyzed for Zn, Pb, Cu, Cd and Ni by the AAS method. The results showed that concentrations of Pb, Cu, Cd and Ni increased along the Narew River due to the accumulation of the elements in water. A significant influence on high heavy metal concentrations in water was produced by the town of Białystok, a source of large amounts of municipal pollutants discharged into the river. This mainly affected the content of Zn, as the highest pollution with this element was detected in the upper Narew River. The lowest Zn concentrations were observed in the Omulew River water, where forests dominated in the area, covering more than 48% of the catchment. The research showed that wetlands and lakes significantly decreased Pb, Cu, Cd and Ni concentrations in flowing water, but the presence of large inhabited areas with dense population and municipal pollution increased concentrations of heavy metals in river water.
Four methods of forecasting: „no-change", LOESS, local linear regression and Holt-Winters were applied to annual minimum water levels observed at ten cross-sections of two tributaries of the Vistula river. The 1-, 2-, ..., 5-year forecasts were made for each year after some initial year, and four quality measures: bias, root mean square error, mean absolute error and maximum absolute error were calculated for each time series and lead time. The naïve model turned out to be always the worst in it bias and almost always very good, sometimes the best regarding the other measures.
Mycoplankton of Vistula River and its main tributaries biomass as well as the number and morphotype diversity was studied in summer and autumn 2011. Summer mycoplankton biomass was within the range of 0.2 – 0.5 μg/l, while in the autumn it was two times wider range (0.1 – 1.3 μg/l). The number of fungi in river water most often did not exceed 1000 – 2000 CFU/ml. Fungi colonies isolated from rivers water were sensitive to the commonly used amphotericine B (10 μg) and gentamicin (10 μg). It seems to be plausible that aquatic fungi can acquire immunity to drugs as a result of horizontal transfer of a gene responsible for drug resistance or as an effect of antibiotics and antimycotics getting into the aquatic ecosystems from wastewaters.
Although some small amounts of mercury in surface water come from natural environment, much higher quantities originate from anthropogenic sources, including industry and agriculture. Mercury readily accumulates in bottom sediments, from which it can return to water, which can be a serious cause of mercury pollution even after other mercury sources are removed from a river’s drainage basin. Concentration of mercury was examined in river waters flowing from basins characterised by different land use and population density. Samples of water were collected from two right tributaries of the Narew River, called the Pisa and the Biebrza, and at six sites in the middle section of the main river. The areas drained by these three rivers lie within the ecosystem known as the Green Lungs of Poland. It was found that the average mercury concentration in the waters of the Narew and its tributaries ranged between 0.3 and 0.9 pg dm-3, being only slightly higher than the concentrations typical of unpolluted territories. The highest mercury content occurred in spring and in the waters from agricultural-forested basins with large towns. Changes in the mercury outflow were associated with accumulation of household pollutants downstream, atmospheric conditions as well as the content of organic matter and suspended solids in the river waters. Low concentration of mineral suspension and organic substance carried by the Pisa River significantly depressed the mercury content in the water of this river. In the Biebrza River, the concentration of both organic and mineral substance was directly proportional to the content of mercury.
The aim of the paper is the evaluation of the surface runoff impact on chemical composition of waters, transport of suspension and dissolved substances out of the catchment in two left-bank tributaries of the lower Wieprza River – Potok Starokrakowski and Jarosławianka. During the flood discharges were several tens times higher than the average recorded in that period. In Potok Starokrakowski the discharge was 500 dm³/s (typical discharges 10-20 dm³/s) and in Jarosławianka 1500 dm³/s (typical discharges 10-40 dm³/s). The rapid increase in discharge in the streams caused activation of suspension transport in both catchments. In Potok Starokrakowski the suspension content in the flood period was 56.5 mg/dm³, while in Jarosławianka 160.3 mg/dm³. In the flood period, a considerable decrease in the concentration of some dissolved substances, including Na+, Ca2+, Mg2+ and Cl-, was observed. Simultaneously, an increase in the concentration of ammonium nitrogen (NH4-N), potassium, total organic carbon and Kjeldahl’s nitrogen (NK) was observed in both streams. Observed flood had huge meaning in suspended and soluted substances transport out of both catchments.
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Aquatic snails of tributaries to the Narew River

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