Effect of a dense inflow on the stratification of a steep-side lake

Limnology and Oceanography
By: , and 

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Abstract

We detail the effect of a small stream of dense inflow that significantly altered the stratification and water quality in a constructed water body in northern British Columbia, Canada. As the dense inflow passed through the epilimnion of the steep-sided lake, it entrained relatively large quantities of water. The resulting mixture of dense inflow and entrained epilimnetic water sank to the bottom of the lake. The removal of water from the epilimnion due to entrainment reduced the epilimnetic thickness. This opposes the normal process of epilimnetic deepening due to wind and convective cooling. The flux of fluid entrained into the dense inflow was calculated to be between 4 and 14 times the inflow, depending primarily on the thickness of the epilimnion. The entrainment had four major effects: (1) it reduced the residence time of the epilimnion from half a year to less than a month; (2) it removed the freshwater cap that resulted from spring ice melt; (3) it enabled fall turnover, which further enhanced deep oxygen content and helped to prevent meromixis from developing in the lake; and (4) it produced a rapid decline in contaminant (i.e., zinc) concentrations in the epilimnion, which received dissolved metals inputs from oxidized sulfide minerals exposed in the subaerial walls of the lake. Given the wide variety of inflows to inland water bodies, some of which are at least seasonally dense, an understanding of the mechanisms detailed here can inform lake management in general, and more specifically, management of water quality in mine-impacted water bodies.

Suggested Citation

Pieters, R., Lawrence, G.A., Leung, A., Crusius, J., Pedersen, T., 2024, Effect of a dense inflow on the stratification of a steep-side lake: Limnology and Oceanography, v. 69, no. 9, p. 1905-1917, https://doi.org/10.1002/lno.12610.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Effect of a dense inflow on the stratification of a steep-side lake
Series title Limnology and Oceanography
DOI 10.1002/lno.12610
Volume 69
Issue 9
Publication Date July 29, 2024
Year Published 2024
Language English
Publisher Association for the Sciences of Limnology and Oceanography
Contributing office(s) Alaska Science Center Water
Description 13 p.
First page 1905
Last page 1917
Country Canada
State British Columbia
Other Geospatial Equity Silver mine
Additional publication details