60
M. Rz˛ etała
classification is mostly made on the basis of their small area) and “storage reservoirs”,
which denote a water body type [1–3]. The term “pond” is useful in hydrobiological
classifications, where it is used to denote a natural or artificial “inland, shallow and
usually freshwater body in which, unlike in a lake, it is not possible to distinguish the
deep water (profundal) zone or the open water (pelagic) zone, and the entire bottom of
the water body is usually overgrown with macrophytes, and thus the only ecological
zone present is the littoral one” [4]. The meaning of the term “storage reservoir” is
also ambiguous in terms of the criterion of the basin’s origin. Storage, i.e. temporary
retention of water, maybe an attribute of any limnic object, and thus the term “storage
reservoir” can be considered to refer more to the hydrological characteristics of a
body of water, its natural significance or economic function rather than its origin
[3, 5].
The most popular criteria for classifying water bodies concern their morphogenesis (basin origin), surface area, capacity and practical significance (tasks, functions),
etc. Other classification criteria are used as well by analogy to the rules of classifying
lakes in terms of their thermal, dynamic and trophic characteristics.
4.2 Origin of Water Bodies
The formation of artificial water bodies is directly or indirectly related to human
activity (Fig. 4.1), and their typology is usually based on the origin of the basin
in which the water accumulates (morphogenesis). Among artificial bodies of water,
the following types are most often distinguished: reservoirs impounded by dams,
flooded mineral workings, levee ponds, water bodies formed in subsidence basins
and hollows, artificial pools and industrial ponds (e.g. with concrete, earth or metal
basins). For some bodies of water, multiple origins can be indicated, e.g. in the case
of those created as a result of river regulation, lakes impounded by dams, etc.
Reservoirs impounded by dams (often referred to as lakes impounded by dams)
are formed as a result of damming up river waters (Fig. 4.2). Dams are constructed
in locations where geological and morphological conditions of the river valley are
favourable for the erection of such structures. The morphometric characteristics of
reservoirs impounded by dams depend on the surface areas and retention capacities
of the valleys flooded with river water. Depth distributions of reservoirs of this type
are determined by the shapes of river valleys and by their longitudinal and transverse
gradients [6–8]. The deepest point of the basin is situated near the bottom outlet of
the dam, and the reservoir becomes shallower towards its edges which are adjacent to
valley slopes and also towards the backwater zone. Reservoirs impounded by dams
have precisely defined tasks already at the stage when their construction is planned,
and a precondition for their proper operation is that a sufficient amount of water is
fed into the reservoir [9]. The largest reservoirs impounded by dams in Poland are
found within the valleys of major rivers—the Vistula River and its tributaries, and
also within the tributaries of the Oder River [10]. Most of these can be found in the
mountains in the south of Poland and also in the lake districts in the northern part of
M. Rz˛ etała
classification is mostly made on the basis of their small area) and “storage reservoirs”,
which denote a water body type [1–3]. The term “pond” is useful in hydrobiological
classifications, where it is used to denote a natural or artificial “inland, shallow and
usually freshwater body in which, unlike in a lake, it is not possible to distinguish the
deep water (profundal) zone or the open water (pelagic) zone, and the entire bottom of
the water body is usually overgrown with macrophytes, and thus the only ecological
zone present is the littoral one” [4]. The meaning of the term “storage reservoir” is
also ambiguous in terms of the criterion of the basin’s origin. Storage, i.e. temporary
retention of water, maybe an attribute of any limnic object, and thus the term “storage
reservoir” can be considered to refer more to the hydrological characteristics of a
body of water, its natural significance or economic function rather than its origin
[3, 5].
The most popular criteria for classifying water bodies concern their morphogenesis (basin origin), surface area, capacity and practical significance (tasks, functions),
etc. Other classification criteria are used as well by analogy to the rules of classifying
lakes in terms of their thermal, dynamic and trophic characteristics.
4.2 Origin of Water Bodies
The formation of artificial water bodies is directly or indirectly related to human
activity (Fig. 4.1), and their typology is usually based on the origin of the basin
in which the water accumulates (morphogenesis). Among artificial bodies of water,
the following types are most often distinguished: reservoirs impounded by dams,
flooded mineral workings, levee ponds, water bodies formed in subsidence basins
and hollows, artificial pools and industrial ponds (e.g. with concrete, earth or metal
basins). For some bodies of water, multiple origins can be indicated, e.g. in the case
of those created as a result of river regulation, lakes impounded by dams, etc.
Reservoirs impounded by dams (often referred to as lakes impounded by dams)
are formed as a result of damming up river waters (Fig. 4.2). Dams are constructed
in locations where geological and morphological conditions of the river valley are
favourable for the erection of such structures. The morphometric characteristics of
reservoirs impounded by dams depend on the surface areas and retention capacities
of the valleys flooded with river water. Depth distributions of reservoirs of this type
are determined by the shapes of river valleys and by their longitudinal and transverse
gradients [6–8]. The deepest point of the basin is situated near the bottom outlet of
the dam, and the reservoir becomes shallower towards its edges which are adjacent to
valley slopes and also towards the backwater zone. Reservoirs impounded by dams
have precisely defined tasks already at the stage when their construction is planned,
and a precondition for their proper operation is that a sufficient amount of water is
fed into the reservoir [9]. The largest reservoirs impounded by dams in Poland are
found within the valleys of major rivers—the Vistula River and its tributaries, and
also within the tributaries of the Oder River [10]. Most of these can be found in the
mountains in the south of Poland and also in the lake districts in the northern part of