Effect of major flow diversion on sediment nutrient release in a stratified reservoir

A process-based, hydrodynamic model that describes the mixing and transport processes in a stratified lake has been coupled to an ecological model to examine the relationship between the stratification and internal nutrient loading. The ecological model includes descriptions of algal production, nutrient cycling (including sediment release) and oxygen dynamics. An example is presented of the use of the model to examine interactions between stratification, sediment nutrient release and phytoplankton production when there is a major diversion of the inflow to a drinking water reservoir.

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Effect of overlying water pH, temperature, and hydraulic disturbance on heavy metal and nutrient release from drinking water reservoir sediments

Water Environment Research ◽

10.1002/wer.1587 ◽

2021 ◽

Author(s):

Cheng Peng ◽

Yunying Huang ◽

Xuchen Yan ◽

Lei Jiang ◽

Xuefei Wu ◽

...

Keyword(s):

Heavy Metal ◽

Drinking Water ◽

Water Reservoir ◽

Nutrient Release ◽

Overlying Water ◽

Reservoir Sediments ◽

Drinking Water Reservoir ◽

Water Ph

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Development of a water temperature-ecological model to stimulate global warming effects on lake ecosystem

Water Science & Technology ◽

10.2166/wst.1996.0627 ◽

1996 ◽

Vol 34 (7-8) ◽

pp. 237-244 ◽

Cited By ~ 1

Author(s):

Masaaki Hosomi ◽

Tetsu Saigusa ◽

Kenichi Yabunaka ◽

Takuya Okubo ◽

Akihiko Murakami

Keyword(s):

Global Warming ◽

Water Temperature ◽

Thermal Stratification ◽

Ecological Model ◽

Nutrient Release ◽

Eddy Diffusion ◽

Nutrient Concentrations ◽

Lake Ecosystem ◽

Phytoplankton Species ◽

Freezing And Thawing

This paper describes a newly developed combined water temperature-ecological (WT-ECO) model which is employed to simulate the effects of global warming on lake and reservoir ecosystems. The WT model includes (i) variations in the eddy diffusion coefficient based on the degree of thermal stratification and the velocity of wind, and (ii) a sub-model for simulating the freezing and thawing processes of surface water, water temperatures, and the mixing rates between two adjacent layers of water. The ECO model then uses these results to calculate the resultant effect on a lake's ecological dynamics, e.g., composition of phytoplankton species, their respective concentrations, and nutrient concentrations. When the model was benchmarked against Lake Yunoko, a dimictic lake, fairly good agreement was obtained over a 4-yr period; thereby indicating it is suitably calibrated. In addition, to assess the effects of global warming on a lake ecosystem, changes in Lake Yunoko's water temperature/quality were simulated in response to an increase in air temperature of 2 - 4°C. Results indicate that such an increase will (i) increase thermal stratification in summer, which increases the nutrient concentrations in bottom water due to nutrient release from bottom sediment, (ii) increase the concentration of phytoplankton at the beginning of the autumn circulation period, and (iii) change the composition of phytoplankton species.

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