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This article presents the results of concentrations of N-NO₂, N-NO₃, Cl⁻, SO₄²⁻, P-PO₄, N-NH₄, Fe, chemical oxygen demand with KMnO₄, HCO₃⁻, Ptotal, acid neutralizing capacity between the pH range of 4.5 and 3.5 along with pH and electrolytic conductivity for Štiavnica Stream (in south-central Slovakia). These parameters were monitored at four monitoring places (Banska Štiavnica, Svaty Anton, Prenčov, and Hontianske Nemce) from 2006 to 2008. The rank order of soluble nitrogen forms on the basis of median values were in Banska Štiavnica N-NH₄>N-NO₂>N-NO₃, in Svaty Anton, Prenčov and Hontianske Nemce N-NO₃>N-NH₄>N-NO₂. The concentration of phosphates phosphor was high in all sampling places, with the highest in Banska Štiavnica (0.29 mg・L⁻¹). Physico-chemical parameters such as pH were in the interval from 6.52 to 7.93, electrolytic conductivity and chemical oxygen demand were highest in Banska Štiavnica (EC = 51.51 mS・m⁻¹, CODMn = 10.46 mg・L⁻¹). The aim of our article is to prove, according to our analyses, that surface water quality has gotten worse and to point out the importance of monitoring smaller streams that are permanently contamined by local settlements.
The study analyses the transfer of F-, Cl-, NO3-, SO42-, Na+, K+, Ca2+, Mg2+, Fe2+, Mn2+ and Zn2+ from bulkprecipitation to throughfall, soil surface flow, vertical flow and intercover flow of water (gravity lysimeters at 20 cm soil depth) in spruce stands of different age classes (1st, 2nd, 5th, 6th), and the amount of these ions flowing out from the Potok Dupniański catchment in the Silesian Beskid Mts. The results cover the year 2000. The concentration and amount of SO4 2- in throughfall systematically increased and the pH value decreased with the age of the stands and with successive elements of the ecosystem. The NH4+ ion was probably absorbed in the canopy, which caused a washout of K+, Mn2+, F- and SO42- in the vegetation season in older stands. In the winter season, Fe2+, Mn2+, Na+ and K+ were washed out from the youngest stands (1st age class), whereas F-, NO3 -, SO42--, K+, Ca2+, Mg2+, Mn2+ and Fe2+ – from older canopies. Decomposition of the organic matter caused a rise in water acidity and an increase in the concentrations of all the analysed ions; their leaching, however, was low (under 1%). Water from intercover flow contributed to an increase in the amount of water and the concentration and amount of ions and to a further decrease in water reaction at a soil depth of 20 cm. All the anions and cations flowed away with water penetrating vertically and horizontally. Considerable amounts of ions, especially SO42-, Na+, K+, Ca2+ and Mg2+, were carried beyond the reach of the main mass of the root system and then out of the catchment, which may adversely affect the development and health of spruce stands.
This paper presents results of bacteriological investigations concerning coastal seawater and sandy sediments in the Three-city region at the outlet of four streams: Kacza (KaS), Swelina (SwS), Grodowy (GS) and Kamienny (KmS). The numbers of facultative psychrophilic bacteria, mesophilic bacteria and indicator bacteria (coliforms, fecal coliforms, fecal enterococci) were determined. It was found that all streams are carrying fecal bacteriological pollution of human and animal origin which contributes to poor quality of coastal seawater and sandy sediments. The lowest sanitary quality was KaS water, where the number of all indicator bacteria, as a rule, exceeded admissible levels. In sandy sediments of the estuaries of all four streams the average number of indicator bacteria was about one order of magnitude higher than in water. Enterococcus was the bacterial indicator that exceeded single water or sediment sample standards most often.
Performance of two data-driven models that were developed using Artificial Neural Networks (ANNs) and Multiple Linear Regression (MLR) approaches were investigated in prediction of Total Nitrogen (TN) concentration in twenty-one river basins in Chugoku district of Japan. Comparison of TN concentration predictions, which were carried out using an ANN-based model and MLR-based model indicated that prediction of the former model (r²=0.94, p<0.01) was more accurate than that of the latter model (r²=0.85, p<0.01). Lack of a sufficient data set that might be considered an obstacle for cross-validating models that are developed was dealt with using a Monte Carlo-based sensitivity analysis of the developed models. This initiative could provide reliable information for judging predictive capacity of the developed models stochastically. Result of sensitivity analysis revealed that predictive capacity of the ANN-based model varied between 0-2 mg/L. Moreover, prediction of the negative outputs was not observed. using the ANN-based model for TN concentration in stream water.
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