Modelling the metalimnetic oxygen minimum in a medium sized alpine lake

We present a one-dimensional physical–biological coupled model for the prediction of water quality. The physical model implements a k-ε turbulent closure for an accurate water temperature representation over a wide range of meteorological data. For the oxygen budget, the one-dimensional diffusion equation is solved using the turbulent diffusivities provided by the turbulence model. Source and sink terms for surface re-aeration, photosynthetic production, respiration, biochemical oxygen demand and sediment oxygen demand are included. The model is forced by measured chlorophyll-a data. We shall report our experience gained with this model in simulating the metalimnetic oxygen minimum of 1996 in Lake Ammer, Germany.