A study of parameter estimation procedures of a model for lake phosphorus dynamics

Abstract Theoretical lake ecosystem models are often constructed by synthesis of proven and hypothesized mechanisms. These include parameters that are determined through visual (graphic) or algorithmic procedures of comparing model output with data, and the models are then considered “calibrated”. These models generally include terms nonlinear in system variables and parameters, which leads to nonuniqueness of the parameter determination. We investigate this problem by examination of our procedures applied to a simplified sub-model of phosphorus dynamics in Greifensee. An attempt is made to reduce the ambiguities by a procedure which assigns a weight to parameter self-consistency using additional simulated data. This approach is still open to criticism and additional approaches are proposed for investigation.