Stefan, Heinz G.Hondzo, M.Fang, XingRasmussen, Anders H.2011-07-122011-07-121994-12https://hdl.handle.net/11299/109041The need for predictive water quality modeling has received renewed interest largely because of increased concern over climate change, acid rain, land use practices, toxic wastes, spills and progressive groundwater pollution. Long~term trends in addition to short term responses, are of increased interest. Process~oriented lake water quality models have been developed previously (e.g. Orlob, 1983; USCE 1986; and Riley and Stefan, 1988). These simulation models are calibrated for individual lakes associated with particular climatic conditions. Water quality models which can be used without recalibration for regional lake assemblages and over several years in a continuous mode (during the open water and the winter ice cover season) have not been previously reported in the literature. The purpose of this report is to describe a first attempt to develop a year-round water quality model to simulate vertical water temperature and dissolved oxygen distributions for a wide range of lake morphometries and meteorological conditions. The model is designed to be driven by the meteorological conditions and to operate in a continuous long~term mode. Although the model represents a great over~ simplification, the stratification dynamics of water temperature and dissolved oxygen can be predicted to a reasonable degree.en-USReport