Dynamics of vertical mixing in a shallow lake with submersed macrophytes

Abstract

[1] A model for vertical turbulent diffusion and stratification in a shallow lake with submersed macrophytes is formulated on the basis of a one-dimensional equation for production, transport, and dissipation of turbulent kinetic energy, coupled with a vertical heat transfer equation. Numerical solutions of the coupled equations allow simulation of the hourly variation of water temperature profiles in a shallow lake as a function of varying weather parameters. The model can be used to simulate water temperature and turbulent kinetic energy profiles in locations of a shallow lake with either dense macrophyte beds or relatively open water. The water temperature simulations are in good agreement with field data from a shallow lake. During the day, macrophyte beds are found to increase the strength of temperature stratification and to reduce the mixed layer depth compared to open water. Macrophyte beds are found to have relatively little effect on nighttime deepening of the mixed layer because of surface cooling. Lateral transport between open water and macrophyte beds of finite horizontal dimensions (patchiness) may limit the accuracy of one-dimensional transport models. Vertical diffusivity coefficient profiles found in this study may be useful to investigate mass transport in shallow lakes with macrophytes.

Circulation and Stream Plume Modeling in Conesus Lake

“…For example, macrophytes create high resistance to stream flow and enhance sediment deposition in the nearshore of a lake [17]. The existence of macrophyte beds has been shown to have implications for vertical mixing and temperature stratification in the offshore of a lake [12].…”

Modeling the Effect of Waves on the Diurnal Temperature Stratification of a Shallow Lake

“…In many studies the evolution of the temperature of shallow lakes and reservoirs is simulated for the water column using vertical, horizontally averaged one-dimensional models, implying that horizontal advective and diffusive transport can be disregarded [3,5,6]. In case of large lakes horizontal uniformity is rarely valid, hence the application of three-dimensional (3D) hydrodynamic models is required for proper calculations.…”

Modeling the influence of benthic primary production on oxygen transport through the water–sediment interface

“…Although the context of this research was extremely shallow salty lagoons of northern Chile, the results presented here can be extended to similar shallow ecosystems including coastal lagoons (del Castillo and Farfán, 1997;López-González et al, 1998), coral reefs (Jimenez et al, 2008(Jimenez et al, , 2011(Jimenez et al, , 2012, shallow lagoons (Timms, 2005;Herb and Stefan, 2005;Alsterberg et al, 2011) or shallow fjords (Attard et al, 2014).…”