Dams and Impounded Rivers - River Dynamics and Integrated River Management - page 396

exhibits a temperature gradient of up to 2 ć /m. Within the hypolimnion, temperatures are typically low,
and decrease only a small amount from the thermocline to the bed of the reservoir. Figure 7.3 illustrates
the thermal stratification in different seasons in the Canyon Lake, Guadalupe River, U.S. (Hannan, 1979).
The temperature distributes uniformly in January but a thermocline develops in July and the epilimnion
and hypolimnion develop near the surface and near the bottom.
Fig. 7.2 Thermal stratification in reservoirs: (a) temperature stratification in summer; (b) homogeneous reservoir
water because turbulence destroys the stratification
Fig. 7.3 Thermal stratification in different seasons in the Canyon Lake, Guadalupe River, U.S. (Hannan, 1979)
Water has its maximum density at about 4 ć . It undergoes a normal thermal expansion—decreasing
density with increasing temperature—from that point upwards and an inverse thermal expansion—