150
D. Absalon et al.
7.4 Characteristics of Physical, Chemical and Biological
Parameters of the Studied Dam Reservoirs
The content of dissolved oxygen in dam reservoirs depends on the trophic state and
morphometric conditions [30]. Average concentrations of dissolved oxygen in most
of the analysed reservoirs exceed limit values for class I water quality (values ≥7.0 mg
O 2 /L). One exception is the Pilchowice reservoir with the lowest average dissolved
oxygen content of 6.83 mg O 2 /L—which makes it fall into water quality class II
(values 5.0–7.0 mg O 2 /L). The Dobczyce reservoir has the highest concentration of
dissolved oxygen, with an average value of 14.0 mg O 2 /L (Fig. 7.2).
Biochemical Oxygen Demand (five days—BOD 5 ) is one of the indexes characterising oxygen conditions. In most reservoirs, average BOD 5 values do not exceed
the limit value for class I (≤3.0 mg O 2 /L) and the lowest value was recorded for
the Klimkówka reservoir—0.97 mg O 2 /L. Average BOD 5 concentrations in reservoirs: Siemianówka, D˛ ebe, Sulejów, Jeziorsko, Rybnik do not exceed the limit value
for class II (3.0–6.0 mg O 2 /L), with the highest average value for the Siemianówka
reservoir—5.40 mg O 2 /L (Fig. 7.3).
The content of organic matter is one of the parameters defining the degree of
environmental pollution. Total organic carbon (TOC) provides full data about the sum
of all organic compounds found in water. Organic matter suspended in water may be
both natural and anthropogenic origin [37]. The lowest average TOC concentration
was recorded for reservoirs located in mountainous areas, with the highest TOC
value of 4.70 mg C/L for the Besko reservoir and the lowest 2.06 mg C/L for the
Fig. 7.2 Distribution of concentrations of dissolved oxygen in analysed reservoirs
D. Absalon et al.
7.4 Characteristics of Physical, Chemical and Biological
Parameters of the Studied Dam Reservoirs
The content of dissolved oxygen in dam reservoirs depends on the trophic state and
morphometric conditions [30]. Average concentrations of dissolved oxygen in most
of the analysed reservoirs exceed limit values for class I water quality (values ≥7.0 mg
O 2 /L). One exception is the Pilchowice reservoir with the lowest average dissolved
oxygen content of 6.83 mg O 2 /L—which makes it fall into water quality class II
(values 5.0–7.0 mg O 2 /L). The Dobczyce reservoir has the highest concentration of
dissolved oxygen, with an average value of 14.0 mg O 2 /L (Fig. 7.2).
Biochemical Oxygen Demand (five days—BOD 5 ) is one of the indexes characterising oxygen conditions. In most reservoirs, average BOD 5 values do not exceed
the limit value for class I (≤3.0 mg O 2 /L) and the lowest value was recorded for
the Klimkówka reservoir—0.97 mg O 2 /L. Average BOD 5 concentrations in reservoirs: Siemianówka, D˛ ebe, Sulejów, Jeziorsko, Rybnik do not exceed the limit value
for class II (3.0–6.0 mg O 2 /L), with the highest average value for the Siemianówka
reservoir—5.40 mg O 2 /L (Fig. 7.3).
The content of organic matter is one of the parameters defining the degree of
environmental pollution. Total organic carbon (TOC) provides full data about the sum
of all organic compounds found in water. Organic matter suspended in water may be
both natural and anthropogenic origin [37]. The lowest average TOC concentration
was recorded for reservoirs located in mountainous areas, with the highest TOC
value of 4.70 mg C/L for the Besko reservoir and the lowest 2.06 mg C/L for the
Fig. 7.2 Distribution of concentrations of dissolved oxygen in analysed reservoirs