Lake retention time (also called the residence time of lake water, or the water age or flushing time) is a calculated quantity expressing the mean time that water (or some dissolved substance) spends in a particular lake. At its simplest this figure is the result of dividing the lake volume by the flow in or out of the lake. It roughly expresses the amount of time taken for a substance introduced into a lake to flow out of it again. The retention time is especially important where pollutants are concerned.
Read more about Lake Retention Time: Global Retention Time, More Specific Residence Times, List of Residence Times of Lake Water
Famous quotes containing the words lake, retention and/or time:
“The best quality tea must have creases like the leathern boot of Tartar horsemen, curl like the dewlap of a mighty bullock, unfold like a mist rising out of a ravine, gleam like a lake touched by a zephyr, and be wet and soft like a fine earth newly swept by rain.”
—Lu Yu (d. 804)
“Unless a group of workers know their work is under surveillance, that they are being rated as fairly as human beings, with the fallibility that goes with human judgment, can rate them, and that at least an attempt is made to measure their worth to an organization in relative terms, they are likely to sink back on length of service as the sole reason for retention and promotion.”
—Mary Barnett Gilson (1877–?)
“all the clocks in the city
Began to whirr and chime:
“O let not Time deceive you,
You cannot conquer Time.”
—W.H. (Wystan Hugh)