9 Assessment of Pollution of Water Resources and Process of Pollution Spreading
203
104, 107]. The second system is provided by Kudelska et al. [59]. The assessment
of lakes’ susceptibility to degradation is based in both systems on similar indicators, a significant part of them are morphometric indices, eg the average depth, lake
volume, the length of the shoreline or the lake surface (Table 9.2). They were determined in the sixties of the last century and in the majority of them they have become
demeanorized, for example due to lake overgrowing. It is now necessary to update
this data, using modern numerical techniques and echosounding in combination with
GPS. Such surveys will also allow assessment of lake water resources.
9.4 “Internal Supply” in Biogenes
Elements accumulated in the ecosystem come back into circulation in various
amounts, at different times and through various mechanisms. The state of trophies
of lakes depends on the intensity of the circulation of matter and on the amount of
biogenic compounds taking part in it [4, 28, 32]. The basic resources of phosphorus
and nitrogen are accumulated in bottom sediments, a much smaller part in organisms,
but the circulation in this ecosystem of this part of resources plays a significant role.
Consumption and the distribution of life and the secretion of various forms of matter
by aquatic organisms are the main ways of its circulation and transformation in the
ecosystem. Separation of mineral nitrogen and phosphorus compounds by invertebrate animals is the basic mechanism of their circulation in the water depth, and also
significant (in addition to bacterial degradation) in bottom sediments (benthos) [33].
The most important processes in the phosphorus retention in bottom sediments are
the sorption and binding of this element by iron hydroxides, the addition of calcium
carbonates and the autogenous formation of minerals. Feeding of biogenic water
contained in bottom sediments plays the most important role during summer stagnation, mainly due to bacteria and release of Fe-P and Al-P connections in anaerobic
conditions [35]. This process is intensified by mixing of near-surface waters closer
to the surface. The release of phosphorus from bottom sediments located within the
epilimnion is much more important than the same process taking place at the border
of sediments and water under anaerobic conditions in hypolimnion [4].
Among the factors determining the rate of matter cycling in the lake, water mixing,
affecting the rate of reactivation of nutrient reserves [66], is of great importance.
Olszewski [29] recognizes that the thermal relations of the lake, subject to climatic
factors of seasonal variability, are an indicator of the dynamics of water masses.
They are modified by the effects of wind, which in turn depends on the morphological characteristics of the bowls. These dependencies are discussed extensively
by many authors [4, 29, 57]. Especially in shallow reservoirs, they determine the
epilimnion range (stratification level), the exchange intensity between epilimnion
and hypolimnion, and between water and bottom [66]. Usually, tanks with high
water mass dynamics are more susceptible to eutrophication. Research conducted
by Kubiak [99] on the largest lakes of Western Pomerania confirmed the principle
that those with intense water mixing are characterized by a higher level of trophies.
203
104, 107]. The second system is provided by Kudelska et al. [59]. The assessment
of lakes’ susceptibility to degradation is based in both systems on similar indicators, a significant part of them are morphometric indices, eg the average depth, lake
volume, the length of the shoreline or the lake surface (Table 9.2). They were determined in the sixties of the last century and in the majority of them they have become
demeanorized, for example due to lake overgrowing. It is now necessary to update
this data, using modern numerical techniques and echosounding in combination with
GPS. Such surveys will also allow assessment of lake water resources.
9.4 “Internal Supply” in Biogenes
Elements accumulated in the ecosystem come back into circulation in various
amounts, at different times and through various mechanisms. The state of trophies
of lakes depends on the intensity of the circulation of matter and on the amount of
biogenic compounds taking part in it [4, 28, 32]. The basic resources of phosphorus
and nitrogen are accumulated in bottom sediments, a much smaller part in organisms,
but the circulation in this ecosystem of this part of resources plays a significant role.
Consumption and the distribution of life and the secretion of various forms of matter
by aquatic organisms are the main ways of its circulation and transformation in the
ecosystem. Separation of mineral nitrogen and phosphorus compounds by invertebrate animals is the basic mechanism of their circulation in the water depth, and also
significant (in addition to bacterial degradation) in bottom sediments (benthos) [33].
The most important processes in the phosphorus retention in bottom sediments are
the sorption and binding of this element by iron hydroxides, the addition of calcium
carbonates and the autogenous formation of minerals. Feeding of biogenic water
contained in bottom sediments plays the most important role during summer stagnation, mainly due to bacteria and release of Fe-P and Al-P connections in anaerobic
conditions [35]. This process is intensified by mixing of near-surface waters closer
to the surface. The release of phosphorus from bottom sediments located within the
epilimnion is much more important than the same process taking place at the border
of sediments and water under anaerobic conditions in hypolimnion [4].
Among the factors determining the rate of matter cycling in the lake, water mixing,
affecting the rate of reactivation of nutrient reserves [66], is of great importance.
Olszewski [29] recognizes that the thermal relations of the lake, subject to climatic
factors of seasonal variability, are an indicator of the dynamics of water masses.
They are modified by the effects of wind, which in turn depends on the morphological characteristics of the bowls. These dependencies are discussed extensively
by many authors [4, 29, 57]. Especially in shallow reservoirs, they determine the
epilimnion range (stratification level), the exchange intensity between epilimnion
and hypolimnion, and between water and bottom [66]. Usually, tanks with high
water mass dynamics are more susceptible to eutrophication. Research conducted
by Kubiak [99] on the largest lakes of Western Pomerania confirmed the principle
that those with intense water mixing are characterized by a higher level of trophies.