206
A. Sh . Khabidov
of oceans, seas, natural and man-made lakes appear to be receding as the effect of
natural processes as well as human intervention. Because of this, investigation of
littoral and shoreline processes provided a basis for integrated coastal planning and
management.
The man-made lakes differ in nature not only from the oceans, marginal and
enclosed seas, but from the natural lakes as well. There are good grounds to believe
that such lakes are not unified depositional sedimentary environments and properly
represent a complex of different ones (Khabidov, 1985; Khabidov et al., 1998;
Zhindarev et al., 1998). Determination of the main environments of man-made lakes
and inherent to them features of coastal processes is the subject of the present work.
This chapter is based on the evidence from reservoirs of plain regions, since, as it is
stated by Avakyan et al. (1987), that these man-made lakes are the most widespread
ones.
Main Peculiar Features of Man-Made Lakes
GENERAL OVERVIEW
A reservoir is a man-controlled and time-varying water body for storage, which is
created within both natural and artificial basins. Since the majority of the lakes are
created by virtue of damming rivers, so far as in general their main features are
associated with river valley morphology and geological peculiarities, 'inherited'
hydrological factors, and seasonal and/or long-term water level fluctuations due to the
river discharge changes and human activities.
Since the morphology of river valleys has been much studied and discussed in
the literature (e.g. Easterbook, 1993; Ritter, 1978), only the features of direct concern
here will be listed. Firstly, the bulk of river valleys have an asymmetric shape.
Secondly, complex-shaped river plains and diversified terraces are common features of
the valleys. Lastly, the relative depth and width of valleys usually increases
downstream in the river because of the base level stepping down and lateral erosion.
However, on numerous occasions the river valley width is the subject of wide variations
due to local geological distinctions.
Among the inherited hydrological factors are channel flows. These flows
(Matarzin et al., 1977) result from the lengthwise gradient of water surface which, in
its turn is produced by the differences in the river discharge at the entrance section of a
man-made lake and at the dam. The gradient peaks at the area of river and water body
junction. Thereupon it decreases approaching zero at the dam. The mean velocity of
channel flows changes in response to changing of water surface gradient. Exceptions to
this rule occur within the cascade of reservoirs where they arise from uneven discharge
at the adjoining hydropower plants, and yet in either case the highest channel flow
velocity is observed in the flooded river channel with lesser flows in the nearshore
areas of the reservoirs.
Seasonal and/or long-term fluctuations occur in the water level of man-made
lakes because of the annual changes of discharge and effective water storage in the
A. Sh . Khabidov
of oceans, seas, natural and man-made lakes appear to be receding as the effect of
natural processes as well as human intervention. Because of this, investigation of
littoral and shoreline processes provided a basis for integrated coastal planning and
management.
The man-made lakes differ in nature not only from the oceans, marginal and
enclosed seas, but from the natural lakes as well. There are good grounds to believe
that such lakes are not unified depositional sedimentary environments and properly
represent a complex of different ones (Khabidov, 1985; Khabidov et al., 1998;
Zhindarev et al., 1998). Determination of the main environments of man-made lakes
and inherent to them features of coastal processes is the subject of the present work.
This chapter is based on the evidence from reservoirs of plain regions, since, as it is
stated by Avakyan et al. (1987), that these man-made lakes are the most widespread
ones.
Main Peculiar Features of Man-Made Lakes
GENERAL OVERVIEW
A reservoir is a man-controlled and time-varying water body for storage, which is
created within both natural and artificial basins. Since the majority of the lakes are
created by virtue of damming rivers, so far as in general their main features are
associated with river valley morphology and geological peculiarities, 'inherited'
hydrological factors, and seasonal and/or long-term water level fluctuations due to the
river discharge changes and human activities.
Since the morphology of river valleys has been much studied and discussed in
the literature (e.g. Easterbook, 1993; Ritter, 1978), only the features of direct concern
here will be listed. Firstly, the bulk of river valleys have an asymmetric shape.
Secondly, complex-shaped river plains and diversified terraces are common features of
the valleys. Lastly, the relative depth and width of valleys usually increases
downstream in the river because of the base level stepping down and lateral erosion.
However, on numerous occasions the river valley width is the subject of wide variations
due to local geological distinctions.
Among the inherited hydrological factors are channel flows. These flows
(Matarzin et al., 1977) result from the lengthwise gradient of water surface which, in
its turn is produced by the differences in the river discharge at the entrance section of a
man-made lake and at the dam. The gradient peaks at the area of river and water body
junction. Thereupon it decreases approaching zero at the dam. The mean velocity of
channel flows changes in response to changing of water surface gradient. Exceptions to
this rule occur within the cascade of reservoirs where they arise from uneven discharge
at the adjoining hydropower plants, and yet in either case the highest channel flow
velocity is observed in the flooded river channel with lesser flows in the nearshore
areas of the reservoirs.
Seasonal and/or long-term fluctuations occur in the water level of man-made
lakes because of the annual changes of discharge and effective water storage in the