ABSTRACT
The physical characteristics associated with water temperature have major effects on the hydrodynamic distribution of water being impounded because of its variable density at different temperatures. The regulation of water temperature in a reservoir depends upon the volume and temperature of the entering water, the volume and temperature of the impounded water, hydrometeorological conditions, the morphometry of the reservoir, the location of the outlets for water withdrawal, and the rate of water withdrawal. Water is generally released through a dam from fixed levels. The regulation of dissolved oxygen levels in a reservoir is influenced by all of the above physical factors, as well as complex biogeochemical processes occurring within the impoundments. The two basic types of reservoirs are single- and multiple-purpose impoundments. The duration that a parcel of water is impounded in a reservoir (theoretical retention time) appears to be the key to understanding the resulting reservoir water quality characteristics.
