304
J. P. Siwek
Przemyskie Foothills). For example, the Drohobyczka 4 drill site yields a value
of 270,000 mg/L [32]. Oxalic waters or waters saturated with free carbon dioxide
(>1000 mg/L) are considered to be young waters and occur in the southern part of the
Magura Beds (Beskid S˛ adecki Mountains) in an area that is characterized by young
Tertiary volcanic activity [2, 23]. Hydrogen sulfide waters (H 2 S) are associated with
the occurrence of tectonic dislocations that enable the migration and enrichment
of groundwater in sulfate ions derived from the dissolution of gypsum, pyrite, and
bitumen [2, 23].
13.2.2 Hydrology and Seasonality
13.2.2.1 Hydrologic Year
One very important factor driving water chemistry changes in the Carpathians, and
especially in stream water, is changes in discharge (hydrologic factor). It is the
most important factor shaping the seasonal water chemistry of stream water in the
Carpathian Foothills [33] and in the Tatra Mountains [9]. Changes in stream discharge
throughout the hydrologic year are triggered by the influx of meltwaters in the spring
and rainwater in the summer. The influx of these waters characterized by low TDS,
low conductivity, and low concentration of most main ions triggers a decline in these
parameters for stream water with increasing discharge. This is due to a dilution of
groundwaters with water characterized by a short time of contact with parent material.
This was documented in the Homerka catchment in the Beskid S˛ adecki Mountains
[34], Stara Rzeka and Wierzbanówka catchments in the Pogórze Wi´ snickie Foothills
[33, 35, 36], and in 23 Tatra area catchments [9, 37]. Nevertheless, the concentrations
of some ions such as K
+ , NO 3
− , and PO 4
3− increase with increasing stream discharge.
This pattern is characteristic of ions whose main source is the soil [38–40].
Research performed in small foothill catchments shows that, at a given discharge,
the conductivity of water and the concentrations of most main ions are lower in spring
and summer than in autumn and winter [12, 33]. This is due to the occurrence of
so-called season hysteresis (Fig. 13.5). Lower conductivity and lower ion concentrations in stream water in the spring and summer result from the flushing of chemical
compounds from soils by snowmelt waters on the onset of snowmelt season (late
winter). Higher conductivity and higher ion concentrations in the autumn and winter
are associated with the influx of these compounds thanks to high rates of chemical
weathering in the warm season of the year [12].
Seasonal changes in Carpathian spring discharge are determined by the seasonal
influx of snowmelt and rain waters in water-bearing layers that also alter their chemical composition. At low discharge, spring waters are characterized by higher TDS,
higher pH, and higher concentrations of main ions than at high discharge. This is
shown in studies by ˙
Zelazny [9] in the Tatra Mountains, Jasik et al. [11] in the Gorce
Mountains, Siwek et al. [13] for the Bieszczady Mountains, and Malata and Motyka
[41] for Babia Góra Massif (Beskid ˙
Zywiecki Mountains).
J. P. Siwek
Przemyskie Foothills). For example, the Drohobyczka 4 drill site yields a value
of 270,000 mg/L [32]. Oxalic waters or waters saturated with free carbon dioxide
(>1000 mg/L) are considered to be young waters and occur in the southern part of the
Magura Beds (Beskid S˛ adecki Mountains) in an area that is characterized by young
Tertiary volcanic activity [2, 23]. Hydrogen sulfide waters (H 2 S) are associated with
the occurrence of tectonic dislocations that enable the migration and enrichment
of groundwater in sulfate ions derived from the dissolution of gypsum, pyrite, and
bitumen [2, 23].
13.2.2 Hydrology and Seasonality
13.2.2.1 Hydrologic Year
One very important factor driving water chemistry changes in the Carpathians, and
especially in stream water, is changes in discharge (hydrologic factor). It is the
most important factor shaping the seasonal water chemistry of stream water in the
Carpathian Foothills [33] and in the Tatra Mountains [9]. Changes in stream discharge
throughout the hydrologic year are triggered by the influx of meltwaters in the spring
and rainwater in the summer. The influx of these waters characterized by low TDS,
low conductivity, and low concentration of most main ions triggers a decline in these
parameters for stream water with increasing discharge. This is due to a dilution of
groundwaters with water characterized by a short time of contact with parent material.
This was documented in the Homerka catchment in the Beskid S˛ adecki Mountains
[34], Stara Rzeka and Wierzbanówka catchments in the Pogórze Wi´ snickie Foothills
[33, 35, 36], and in 23 Tatra area catchments [9, 37]. Nevertheless, the concentrations
of some ions such as K
+ , NO 3
− , and PO 4
3− increase with increasing stream discharge.
This pattern is characteristic of ions whose main source is the soil [38–40].
Research performed in small foothill catchments shows that, at a given discharge,
the conductivity of water and the concentrations of most main ions are lower in spring
and summer than in autumn and winter [12, 33]. This is due to the occurrence of
so-called season hysteresis (Fig. 13.5). Lower conductivity and lower ion concentrations in stream water in the spring and summer result from the flushing of chemical
compounds from soils by snowmelt waters on the onset of snowmelt season (late
winter). Higher conductivity and higher ion concentrations in the autumn and winter
are associated with the influx of these compounds thanks to high rates of chemical
weathering in the warm season of the year [12].
Seasonal changes in Carpathian spring discharge are determined by the seasonal
influx of snowmelt and rain waters in water-bearing layers that also alter their chemical composition. At low discharge, spring waters are characterized by higher TDS,
higher pH, and higher concentrations of main ions than at high discharge. This is
shown in studies by ˙
Zelazny [9] in the Tatra Mountains, Jasik et al. [11] in the Gorce
Mountains, Siwek et al. [13] for the Bieszczady Mountains, and Malata and Motyka
[41] for Babia Góra Massif (Beskid ˙
Zywiecki Mountains).