Circulation and Stream Plume Modeling in Conesus Lake

Abstract

A three-dimensional hydrodynamic model that includes the effect of drag from macrophytes was applied to Conesus Lake to study the seasonal circulation and thermal structure during spring and early summer. Local weather conditions and stream flow data were used to drive the model. The drag coefficient for macrophytes was calculated as a function of leaf density. In general, the model results show good agreements with the observations, including vertical temperature profiles measured at two locations and average surface temperature derived from calibrated thermal imagery for large-scale simulations of the entire lake. Additional high-resolution simulations were carried out to understand water circulation and transport of sediment and model-generated tracer during hydrometeorological events at stream mouths for two experimental sites. The model results show that the plume development at stream mouths during storm events in Conesus Lake are site-dependent and may either be current-or wind-driven. The results also show a significant effect from the presence of macrophytes on sediment deposition near stream mouths.

Nonpoint source reduction to the nearshore zone via watershed management practices: Nutrient fluxes, fate, transport and biotic responses — Background and objectives

“…The distribution of nutrient-enriched water from streams into the nearshore of the lake is determined by the nature of the entry plumes of streams and lake circulation (Trexler et al, 2006). Li et al (2007) have documented the flow regimes in and around two creeks in Conesus Lake. This three-dimensional, macrophyte-drag hydrodynamic model demonstrates that nutrient-laden stream water is focused as a result of currents, local bathymetry, and prevailing winds into a macrophyte bed where metaphyton are prevalent.…”

A case study of chlorine transport and fate following a large accidental release

“…ALGE includes a freesurface simulator, first-order chemical reactions, tracer transport, particle transport deposition/resuspension, and distribution coefficient-based modeling of chemical adsorption/desorption to particles. The model has been extensively used to simulate sediment and pollutant transport and thermal stratification in large lakes and estuaries (Garrett et al, 2005;Li et al, 2007;Blanton et al, 2009). ALGE is also used to compute transport, diffusion and deposition of aqueous tracers and has been validated against a unique radioactive tracer database (Blanton et al, 2009).…”

Real-time observation and prediction of physical processes in a typhoon-affected lake

“…The bottom boundary in the model adopts the quadraticform shear stress, with a roughness height of 0.05 m in the lake area. For stem-type vegetation (e.g., Sparganium emersum) in the marsh area under the flood condition, the drag coefficient of the shear stress is proportional to the grass density (m 2 of grass surface per m 3 of water) (Fischer-Antze et al 2001;Gerber and Les 1994;Li et al 2008).…”