206
J. Kubiak and S. Machula
Table 9.3 Factors for estimation of lake water quality by Kudelska et al. [59] and Kudelska and
Soszka [109]
Index
Unit
Season
Type
of
lake
Layer
of
water
I class II
class
III
class
IV
class
Mean
hypolimnetic
oxigenation
%O 2
Summer
S
≥40
≥2
≥1
<1
O 2 content
mg O 2 dm −3 Summer
NS
bottom ≥40
≥20
≥5
<5
ChZTcr
mg O 2 /dm 3
Summer
NS
surface ≤20
≤30
≤50
>50
BZT 5
mg O 2 /dm 3
Summer
S;NS surface ≤2
≤4
≤8
>8
BZT 5
mg O 2 /dm 3
Summer
S
bottom ≤2
≤5
≤10
>10
Phosphates
mgP PO4 /dm 3 Spring
S;NS surface ≤0.02 ≤0.04 ≤0.08 >0.08
Phosphates
mgP PO4 /dm 3 Summer
S
bottom ≤0.02 ≤0.04 ≤0.08 >0.08
Total
phosphorus
mgP/ dm 3
Summer
S
bottom ≤0.06 ≤0.15 ≤0.60 >0.60
Total
phosphorus
mgP/ dm 3
Average
(spring+summer)
S;NS surface ≤0.05 ≤0.10 ≤0.20 >0.20
Mineral
nitrogen
mgN/dm 3
Spring
S;NS surface ≤0.20 ≤0.40 ≤0.80 >0.80
Ammonia
nitrogen
(N NH4 )
mgN NH4 /dm 3 Summer
S
bottom ≤0.20 ≤1.0 ≤5.0 >5.0
Total
nitrogen
mgN/dm 3
Average
(spring+summer)
S;NS surface ≤1.0 ≤1.5 ≤2.0 >2.0
Conductivity μS/cm
Spring
S;NS surface ≤250 ≤300 ≤350 >350
Chlorophyll mg/m 3
Average
(spring+summer)
S;NS surface ≤8.0 ≤15.0 ≤25.0 >25.0
Seston dry
mass
mg/dm 3
Average
(Spring+summer)
S;NS surface ≤4.0 ≤8.0 ≤12.0 >12.0
Visibility
m
Average
(Spring+summer)
S;NS surface ≥4.0 ≥2.0 ≥1.0 <1.0
anthropopressure (intensive agriculture, point sources of pollution). Occurring in the
surface layers of high-oxygenation, it is considered an indicator of a high level of
trophic lakes. The lack of oxygen in the bottom layers of waters, also in winter,
confirms the high level of trophies [4, 57].
9.6 Conclusion
Poland’s membership in the European Union means that the necessary measures to
assess the quality and size of lake water resources, as well as to protect them. It
is necessary to determine the level of trophies and the impact of the catchment on
lakes and their natural susceptibility to degradation, which will allow to determine