, Volume 59, Issue 3, pp 213–221 | Cite as

Vertical diffusion and nutrient transport in a tropical lake (Lake McIlwaine, Rhodesia)

  • Richard D. Robarts
  • Peter R. B. Ward


Measurements of the vertical temperature in tropical Lake McIlwaine were used to calculate the time-averaged (≃ 6 months) vertical diffusivity coefficient (Kz) in the metalimnion and hypolimnion. The mean value of Kz (0.21 cm2 s−1) was correlated with the lake surface area. The mass transport rates of PO4-P and NH4-N, upward from the hypolimnion to the metalimnion, were calculated using Kz and measured values of the nutrient concentration gradients. During a period of 4.5 months when the water was stably stratified, PO4-P was transported upward at a mean rate of 42 kg day−1 and NH4-N at a mean rate of 162 kg day−1 over the entire lake.


tropical lake vertical diffusion nutrient transport 


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Copyright information

© Dr. W. Junk b.v. Publishers 1978

Authors and Affiliations

  • Richard D. Robarts
    • 1
  • Peter R. B. Ward
    • 1
  1. 1.Hydrobiology Research Unit; Department of Civil EngineeringUniversity of Rhodesia SalisburyRhodesia

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