The effect of anthropogenic and natural factors on the prevalence of physicochemical parameters of water and bacterial water quality indicators along the river Bialka, southern Poland.

This study was aimed to determine the anthropogenic and natural factors affecting spatial and temporal changes in the physicochemical parameters and bacterial indicators of water quality in the river Bialka. The impact of intensive development of the tourist infrastructure on the quality of river water and the potential health threats to tourists was also assessed. Water samples were collected over a period of 2.5 years, once per each month in four sites along the river. Temperature, electrolytic conductivity, pH, and water level were measured onsite; flow rate data were acquired from the Institute of Meteorology and Water Management; chemical analyses allowed to determine the amount of fourteen ions, while microbiological indicators included total and thermotolerant coliforms, total and thermotolerant Escherichia coli, and mesophilic and psychrophilic bacteria. The combination of hydrological, hydrochemical, and microbiological methods generated large amount of data, which were processed by multivariate statistical analysis. A downstream cumulative effect was observed in the contamination of the river water. Fecal coliforms and E. coli were detected in all sites, suggesting the source of fecal contamination even in the protected areas. Intensive development of a ski resort and the related infrastructure, together with the need to accommodate numerous tourists in the examined region, has an evident environmental impact. The resulting deterioration of water quality poses health risks to tourists, as water from the Bialka river is used for a variety of purposes, including as a raw drinking water or for artificial snowing of ski slopes. The seasonal changes in the physicochemical parameters mainly result from varying natural factors that shape the water quality in the studied region. The differences in the number of analyzed microorganisms result from seasonal variation in touristic activity and are affected mostly by point sources of sewage inflow.

Factors and Mechanisms Affecting Seasonal Changes in the Prevalence of Microbiological Indicators of Water Quality and Nutrient Concentrations in Waters of the Bialka River Catchment, Southern Poland.

This 3-year study was aimed to understand the factors and mechanisms that cause the temporal changes in the concentration of microbiological indicators of water quality and nutrient concentration in selected sites of the Bialka river catchment (southern Poland) situated in direct vicinity of the largest ski station in the region. The analysis comprised 35 sampling campaigns conducted in five sites. Water temperature, pH, and electrical conductivity were measured during sampling, laboratory analyses included determination of the selected nutrients content (NH4, NO3, NO2, PO4); and the number of mesophilic and psychrophilic bacteria, coliforms, fecal coliforms, and Escherichia coli. Based on the cluster analysis, the collected samples were grouped into three to four groups, depending on the most characteristic features. Seasonal variation was evident, showing the predominance of either anthropogenic or natural-environment factors, depending on the considered season. On the other hand, principal component analysis revealed clear effect of various forms of land use in different sites.

Effect of deforestation on stream water chemistry in the Skrzyczne massif (the Beskid Slaski Mountains in southern Poland).

The purpose of the study was to identify the factors affecting stream water chemistry in the small mountain catchments deforested to varying degrees, from 98.7 to 14.1%, due to long-term acid deposition. Water samples were collected monthly in 2013 and 2014 from 17 streams flowing across three distinct elevation zones in the Skrzyczne massif (Poland): Upper, Middle and Lower Forest Zone. Chemical and physical analyses, including the pH, electrical conductivity (EC), total mineral content (Mt), water temperature, and the concentrations of Ca(2+), Mg(2+), Na(+), K(+), HCO3(-), SO4(2-), Cl(-), and NO3(-), were conducted. Based on Principal Component Analysis (PCA), the most important factor affecting water chemistry was human impact associated with changes in pH, SO4(2-) concentration, and the concentration of most of the main ions. The substantial acidity of the studied environment contributed to the exclusion of natural factors, associated with changes in discharge, from the list of major factors revealed by PCA. All of the streams were characterized by very low EC, Mt, and low concentrations of the main ions such as Ca(2+) and HCO3(-). This is the effect of continuous leaching of solutes from the soils by acidic precipitation. The lowest parameter values were measured for the streams situated in the Upper Forest Zone, which is associated with greater acid deposition at the higher elevations. In the streams located in the Upper Forest Zone, a higher percentage of SO4(2-) occurred than in the streams situated in the Middle and Lower Forest Zones. However, the largest share of SO4(2-) was measured in the most deforested catchment. The saturation of the studied deforested catchment with sulfur compounds is reflected by a positive correlation between SO4(2-) and discharge. Hence, a forest acts as a natural buffer that limits the level of acidity in the natural environment caused by acidic atmospheric deposition.