174
R. Ula´ nczyk et al.
evaluation of the recreational potential, an evaluation of planned remedial measures
and support to the state environmental monitoring system.
Keywords Lake · Reservoir · Ecosystem · Model · Case study · Impact
assessment · Poland
8.1 Introduction to Models and Model-Based Decision
Support Systems
An increase in anthropogenic pressures results in the deterioration of water quality
in rivers, lakes, and reservoirs [1]. Because of the severity of the problem, numerous
actions aimed at the improvement of the water quality are undertaken to present
various methods applied to the assessment of the water quality status and the
prediction of effects of corrective measures [2–5].
Water quality is potentially the best in lakes and reservoirs of relatively large
depths and volumes and of small catchment areas with no sources of pollution. On
the contrary, water bodies which are shallow, contain a smaller amount of water and
have large catchment areas, including agriculture and dense residential areas are much
more sensitive to pressures [6]. In flow-through lakes and reservoirs characterised by
a short retention time physical, chemical and biological processes depend to a large
extent on the status of contributing streams. By contrast, large lakes and reservoirs
that have low water exchange rates develop own ecosystems. Features mentioned
above, as well as other forms of water dynamics (such as waves, horizontal and
vertical currents, stratifications and mixing events), have a definitive influence on the
water quality.
To cope with the problem of lack of readily available information on the status
of water resources and factors affecting these resources more and more complex
models and decision support systems (DSS) are being developed and applied at
various scales (local, national, international). These tools should support the expert
who analyses processes occurring in a reservoir based on clearly defined objectives
and based on the knowledge of the expert and of the model developer. One of the
model types is a physical model that represents a reservoir, a lake, or a hydraulic
structure in a defined scale. Such models are not widely applied nowadays because of
the cost and the duration of construction and limited capabilities of parameterization
(adjustments) and scope of simulations. Physical models are also prone to ineffectively represent force ratios which are adequate to the model scale; another issue is
the problem of scaling of various dimensions of such models (linear, square, cubic)
[7]. Physical models were used mostly before the sufficiently fast computers were
developed and available. An example of such a model is the Vistula River model
constructed to simulate the mixing of cooling water discharged from the Kozienice
power plant and reported in 1978 [8]. At present, physical models are still in use [e.g.,
9, 10], however, their application is aimed primarily to validate mathematical models
[11–13]. The latter is the most widely used type of models. Mathematical models
R. Ula´ nczyk et al.
evaluation of the recreational potential, an evaluation of planned remedial measures
and support to the state environmental monitoring system.
Keywords Lake · Reservoir · Ecosystem · Model · Case study · Impact
assessment · Poland
8.1 Introduction to Models and Model-Based Decision
Support Systems
An increase in anthropogenic pressures results in the deterioration of water quality
in rivers, lakes, and reservoirs [1]. Because of the severity of the problem, numerous
actions aimed at the improvement of the water quality are undertaken to present
various methods applied to the assessment of the water quality status and the
prediction of effects of corrective measures [2–5].
Water quality is potentially the best in lakes and reservoirs of relatively large
depths and volumes and of small catchment areas with no sources of pollution. On
the contrary, water bodies which are shallow, contain a smaller amount of water and
have large catchment areas, including agriculture and dense residential areas are much
more sensitive to pressures [6]. In flow-through lakes and reservoirs characterised by
a short retention time physical, chemical and biological processes depend to a large
extent on the status of contributing streams. By contrast, large lakes and reservoirs
that have low water exchange rates develop own ecosystems. Features mentioned
above, as well as other forms of water dynamics (such as waves, horizontal and
vertical currents, stratifications and mixing events), have a definitive influence on the
water quality.
To cope with the problem of lack of readily available information on the status
of water resources and factors affecting these resources more and more complex
models and decision support systems (DSS) are being developed and applied at
various scales (local, national, international). These tools should support the expert
who analyses processes occurring in a reservoir based on clearly defined objectives
and based on the knowledge of the expert and of the model developer. One of the
model types is a physical model that represents a reservoir, a lake, or a hydraulic
structure in a defined scale. Such models are not widely applied nowadays because of
the cost and the duration of construction and limited capabilities of parameterization
(adjustments) and scope of simulations. Physical models are also prone to ineffectively represent force ratios which are adequate to the model scale; another issue is
the problem of scaling of various dimensions of such models (linear, square, cubic)
[7]. Physical models were used mostly before the sufficiently fast computers were
developed and available. An example of such a model is the Vistula River model
constructed to simulate the mixing of cooling water discharged from the Kozienice
power plant and reported in 1978 [8]. At present, physical models are still in use [e.g.,
9, 10], however, their application is aimed primarily to validate mathematical models
[11–13]. The latter is the most widely used type of models. Mathematical models