Turbulent transport of phytoplankton in artificially destratified reservoirs

Abstract

Temperature and density stratification potentially decreases the productive volume of a reservoir and can reduce water quality. During this period primary production is restricted to the epilimnion whilst anoxic conditions exist in the hypolimnion. Eutrophication of reservoirs compounds the deterioration of water quality, and coupled with the effects of stratification, create physical conditions that are optimal for the growth of cyanobacteria and development of algal blooms. Artificial destratification is used to improve water quality, and is a potential method to manage cyanobacterial growth. Through destratification systems, turbulent jets/plumes are created within the water column, which dissipate radially, creating a horizontal intrusion. Phytoplankton will be entrained within the intrusion, thus experiencing an altered environment. To predict the fate of the phytoplankton cell, the characteristics of the jet/plume must be understood. The flow field from artificial destratification techniques will be investigated with the aim to develop a numerical model describing turbulent intensity and dissipation, which is to be coupled with a growth-diffusion model to predict the population dynamics of phytoplankton.