88
J. Dawidek et al.
human activity – will be discussed. The environment of river valleys is characterized by a wide variety of processes and forms resulting from them. Limnic forms,
although are frequently observed in some valleys, are generally poorly recognized,
and their retention and ecological potential are underestimated in the context of river
bed regulation and hydrotechnical interventions in valleys. The floodplain lakes,
however, are an essential element of small retention of valley waters. Due to the
diversity of types: genetic, balance, hydrochemical, hydrobiological and other, they
are also a very attractive subject of research. The specificity of lakes located in river
valleys is often characterized by a distinct separation from the environment of river
waters, which encourages research and practical solutions aimed at the protection or
renaturalization of the limnic environment.
6.2 Definition of Floodplain Lakes
In world literature, the floodplain lakes are called differently. Examples of terms are:
“neck cutoff” [1–3], oxbow lake [4–6], fluvial lake [7, 8], or more rarely “river lake”
[9], hydro-biological “limnocren” [10, 11], hydrological “floodplain lake” [12–16].
In the Polish literature, especially in reference to lakes, the creation of which is
the result of regulatory and hydrotechnical works in river valleys, apart from the
general and imprecise name “old riverbed,” there are also names: quasi-ox-bows
[17], anthropogenic reservoirs, post-training reservoirs [18]. Sometimes local names
are used, which are derived from river names (e.g., in the Vistula valley – “wi´ sliska”,
in the Odra valley – “odrzyska”, Warta – “warciska”, Bug – “bu˙ zyska”). A separate
problem is the definition of a floodplain lake, which is not precise. A general definition
of a lake assumes the natural origin of a basin in which water accumulates (from
surface and groundwater supply) and the advantage of recharge over losses. However,
an important criterion assuming the existence of turbulent flow of river waters through
a basin during potamophase, as well as autonomous areas with a laminar character of
water movement and stagnation zones, should be added. The number of floodplain
lakes within particular genetic groups, presented in Fig. 6.1, depends on macroscale
features of the natural environment (e.g., geological structure, relief, climate and
others) and human pressure, while the way of functioning is favored by the local
conditions of their catchment areas. The ecological separateness of reservoirs is
commonly observed, which often determines the uniqueness of floodplain lakes.
6.3 Materials and Methods
The analyses of natural floodplain lakes was based mostly on published papers
concerning various river systems. Fluvial, morphological, hydrochemical and hydrobiological aspects were analyzed in order to quantify the main factors determining
floodplain lakes heterogeneity. A representative group of temperate zone floodplain
J. Dawidek et al.
human activity – will be discussed. The environment of river valleys is characterized by a wide variety of processes and forms resulting from them. Limnic forms,
although are frequently observed in some valleys, are generally poorly recognized,
and their retention and ecological potential are underestimated in the context of river
bed regulation and hydrotechnical interventions in valleys. The floodplain lakes,
however, are an essential element of small retention of valley waters. Due to the
diversity of types: genetic, balance, hydrochemical, hydrobiological and other, they
are also a very attractive subject of research. The specificity of lakes located in river
valleys is often characterized by a distinct separation from the environment of river
waters, which encourages research and practical solutions aimed at the protection or
renaturalization of the limnic environment.
6.2 Definition of Floodplain Lakes
In world literature, the floodplain lakes are called differently. Examples of terms are:
“neck cutoff” [1–3], oxbow lake [4–6], fluvial lake [7, 8], or more rarely “river lake”
[9], hydro-biological “limnocren” [10, 11], hydrological “floodplain lake” [12–16].
In the Polish literature, especially in reference to lakes, the creation of which is
the result of regulatory and hydrotechnical works in river valleys, apart from the
general and imprecise name “old riverbed,” there are also names: quasi-ox-bows
[17], anthropogenic reservoirs, post-training reservoirs [18]. Sometimes local names
are used, which are derived from river names (e.g., in the Vistula valley – “wi´ sliska”,
in the Odra valley – “odrzyska”, Warta – “warciska”, Bug – “bu˙ zyska”). A separate
problem is the definition of a floodplain lake, which is not precise. A general definition
of a lake assumes the natural origin of a basin in which water accumulates (from
surface and groundwater supply) and the advantage of recharge over losses. However,
an important criterion assuming the existence of turbulent flow of river waters through
a basin during potamophase, as well as autonomous areas with a laminar character of
water movement and stagnation zones, should be added. The number of floodplain
lakes within particular genetic groups, presented in Fig. 6.1, depends on macroscale
features of the natural environment (e.g., geological structure, relief, climate and
others) and human pressure, while the way of functioning is favored by the local
conditions of their catchment areas. The ecological separateness of reservoirs is
commonly observed, which often determines the uniqueness of floodplain lakes.
6.3 Materials and Methods
The analyses of natural floodplain lakes was based mostly on published papers
concerning various river systems. Fluvial, morphological, hydrochemical and hydrobiological aspects were analyzed in order to quantify the main factors determining
floodplain lakes heterogeneity. A representative group of temperate zone floodplain