Part 9. Ecological and Hydrological Interactions
Published Online: 15 APR 2006
Copyright © 2005 John Wiley & Sons, Ltd
Encyclopedia of Hydrological Sciences
How to Cite
Marzolf, G. R. and Robertson, D. M. 2006. Reservoirs. Encyclopedia of Hydrological Sciences. 9:109.
- Published Online: 15 APR 2006
Reservoirs are surface water impoundments that result from the construction of dams on streams and rivers. Limnological principles are applicable to understanding reservoir functions and the processes that control them because they exhibit lake-like characters (see Lake Ecosystems – Lake Ecosystems (Stratification and Seasonal Mixing Processes, Pelagic and Benthic Coupling). The basic water qualities of reservoirs are dependent, however, on the river that was impounded in their formation. The river's inflow dominates the upstream reaches of reservoirs. Lacustrine processes become more controlling as advective forces diminish and wind-mixing and solar heating become influential forcing factors and as the cross section of the basin widens and deepens downstream. This transition from riverine to lacustrine imposes longitudinal gradients in reservoirs that emerge as their central feature. Designs of dams and their operating schedules have considerable influence on these in-reservoir patterns and on the effects of the dam in the downstream river downstream. Various models have been developed to describe the physical, chemical, and biological processes in reservoirs. Additional studies will lead to further information to improve the models, which in turn will lead to a better understanding and management of reservoirs.