The figure below is from Thornton, Kimmel and Payne
(1990), Figure 5.9. The trends it shows are based on the assumption
that there is just one, main inflowing river that drains a relatively large
area of landscape, and that there are no large side arms or inflows.
The three conditions are determoined by the rate of nutrient loading,
especially phosphorus loading, from the main inflowing river. For comparison
with standard zones in reservoirs, see the page on longitudinal
zones in reservoirs.

Last revised November 9, 1999.