The three-dimensional hydrodynamic Estuary, Lake and Coastal Ocean Model (ELCOM) was coupled to the ecological Computational Aquatic Ecosystem Dynamics Model (CAEDYM) and to an underflow model to simulate the fate of the constituents from three flood underflow events in Lake Burragorang, Australia, in order to verify the changes in the hydrodynamical behavior that could lead to an algal bloom when the lake water level is low as a consequence of climate change. Simulated patterns of temperature, dissolved oxygen, and turbidity compared well with field data. The ELCOM-CAEDYM simulations demonstrated that the vertical excursion induced by an intrusion depended on the volume of the lake before the arrival of the inflow, on the volume of water inserted by the inflow, and on the proximity between the top insertion of the inflow and the surface layer of the lake. When the water level was low and the inflow volume was high, the underflow constituents mixed into the surface layer and triggered a major algal bloom.

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The energy transfer from basin-scale internal waves to internal nonlinear waves was investigated in a large, deep subalpine lake through a combination of field data and three-dimensional hydrostatic and nonhydrostatic modeling. The response of the internal wave field induced by two storm events, with distinct characteristics, showed that, for the whole lake, around 15% of the total potential energy contained in the basin-scale internal waves was transferred to nonlinear internal waves in response to moderate forcing, the large transfer being the direct result of the small surface layer thickness compared with the depth of the lake. Locally, the energy transfer to nonlinear waves was up to 30% for the more severe forcing. To model such energy transfers, a nonhydrostatic three-dimensional hydrodynamic model was required; this implies that the inclusion of nonhydrostatic effects is essential for accurate modeling of ecological processes in deep large lakes, which is a challenge considering currently available computational resources.

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