Modelling values of river macrophyte metrics using artificial neural networks

The results of field research at 230 river sections located throughout Poland were used to examine the possibility of predicting values of macrophyte metrics of ecological status. Artificial intelligence methods such as artificial neural networks were used in the modelling. The physicochemical parameters of water (alkalinity, conductivity, nitrate and ammonium nitrogen, reactive and total phosphorus, and biochemical oxygen demand) were used as the explanatory (modelling) variables. The explained (modelled) parameters were the Polish MIR (Macrophyte Index for Rivers), the British MTR (Mean Trophic Rank) and the French IBMR (River Macrophytes Biological Index). The quality of the constructed models was assessed using the normalized root mean square error (NRMSE) and the r-Pearson's linear correlation coefficient between variables modelled by the networks and calculated on the basis of the botanical research. These analyses demonstrated that the network modelling MIR values had the highest accuracy. The lowest prediction accuracy was obtained for MTR and IBMR indices. The differences between particular models are likely to result from better adjustment of the Polish method to local rivers (particularly in terms of indicator species used). ...

Flow patterns for drying and wetting of a retention reservoir bed-numerical modeling

This paper deals with one of the aspects important from the point of view of water quality maintenance in storage reservoirs, namely the dynamics of water currents that accompany changes of the water surface elevation in such reservoirs. Numerical simulations were conducted to back observations that high discharges are in the long term beneficial to water quality in the reservoir. Calculations made using the AdH finite elements model confirmed that the water current pattern in shallow regions varies greatly with the total discharge value. The sample analysis shown in this article concerns a mid-size storage reservoir of Tresna located in southern Poland. It appears that for small discharges the currents that wet some areas of the previously dry reservoir bed are similar to reversed currents that occur when the area is dried. Thus some amounts of water may move from one stagnant area to another forth and back and then the water exchange is limited. It means that it is not enough to lower the water level within the reservoir steering rules and then raise it again to be assured that the water quality improves in the reservoir, especially in the lull parts. But for higher discharges the current pattern ...

CHANGES OF WATER POLLUTION DYNAMICS IN VISTULA RIVER ON WARSAW CITY AREA

The paper presents change of water quality within Vistula River in the city of Warsaw. Water samples for analysis were taken from four different measurement points in the period from February to June 2016. Based on the results of laboratory studies it was demonstrated that the Vistula River in Warsaw is exposed to the input of pollutants contributing to increase the salinity, especially in winter and early spring. The concentration of both chlorides and sulphates were highest in February and was decreasing in subsequent months of the year. At the same time it has been shown that during the entire study period the concentration of Cl- ion exceeded the limit values for water quality II class in Poland. While the SO42- concentrations in water samples taken in the winter months (February-March) exceeded the limit values for the second quality class, in April, it was within the acceptable range for II class water quality, and in May and June does not exceed the value referred to as standard for I class of water quality. Based on the analysis of indicators of nutrients (N-NH4, N-NO3, Ptot.) it was found that the Vistula is not exposed to eutrophication due to their low ...

EVALUATION OF MICROBIAL QUALITY OF WATER IN THE FOUNTAINS IN KRAKOW

Fountains are decorative elements that improve the attractiveness and visual qualities of urban environments. They can give refreshment to residents on a hot, sunny day. Despite the prohibitions on bathing in these facilities people often have contact with fountain water. It should be emphasized that poor quality of water from fountains can be dangerous for human health. This study was aimed at evaluating microbial contamination of water in Krakow fountains (fountain from Szczepański Square, fountain on the Groble Square, "Chopin" fountain near the philharmonic, "Stone" fountain on the Maria Magdalena Square and the fountain on the Main Market Square). Microbiological analyses were conducted to determine the total number of microorganisms at 36±2oC after 48 hours (mesophilic bacteria) and the total number of microorganisms at 22±2ºC after 74 hours (psychrophilic bacteria). In addition, the coliform bacteria, Escherichia coli and Closridium perfringens were also examined. The results have shown a high degree of microbiological contaminants in the tested water samples. The lowest contamination of water was observed in the fountain on the Szczepański Square and in nozzle water from the fountain on the Groble Square. The highest numbers of bacteria were found in "Stone" fountain at the Maria Magdalena Square. ...

ANALYSIS OF THE CONTENT OF POLLUTANTS IN SURFACE WATER IN THE COMMUNE OF OSTRZESZÓW

This paper presents the results of physical and chemical tests of surface water samples taken from the areas of the Ostrzeszów Commune, which is part of the Ostrzeszów County, located in the southern part of the Wielkopolska Province. The Ostrzeszów commune is included in the urban-rural areas. The physicochemical analysis of surface waters covered samples taken from seventeen measurement and control points from places as accessible as possible. The water quality was assessed in accordance with the applicable regulations of the Minister of the Environment. Surface waters were characterized by typical variability for agricultural areas, i.e. slightly alkaline, pH in the range of 7.5-8.45; specific conductivity in the range of 246-512 μS/cm; turbidity in the range of 1.7-10.5 NTU; total hardness in the range of 1.6-3.2 mmol∙dm-3 Ca2+, Mg2+; alkalinity in the range of 66-142 mg∙dm-3 CaCO3; chloride content in the range of 19-47 mg/dm3 Cl-; content of biogenic compounds, ie: nitrites in the range of 0.02-0.36 mg∙dm-3 N-NO2-; nitrates in the range of 0.05- 4,9 mg∙dm-3 N-NO3-; ammonium ion in the range of 0.04-0.94 mg∙dm-3 N-NH4+; the content of orthophosphate in the range of 0.11-1,56 mg∙dm-3 P-PO43-. The content of metals, i.e. manganese Mn, Fe iron, was characterized by ...