ELMO, a 3-D water quality model for nutrients and chlorophyll: first application on a lacustrine ecosystem

Water quality degradation is a worldwide object of concern, involving the development of management tools. 1-D ecological modeling is now a common approach to investigate the seasonal time scale of the dominant processes in aquatic ecosystems. The purpose of this study was to determine the hydrodynamic and ecological responses of the system to short forcing events such as strong winds or flood, when the 1-D assumption is no longer valid. To reach this goal, we developed a 3-D ecological model that describes the biogeochemical processes in the lake and the sedimentary transport. It was applied on the lake Burragorang (near Sydney, Australia). Results show that for wind events, lateral heterogeneities may be as strong as in the vertical direction. If there are major hydrodynamic influences on the ecosystem behavior, living communities responses seem to be very quick.