Simulation and Analysis of Phosphorus Transformation and Phytoplankton Dynamics in Relation to the Eutrophication of Lake Balaton

A mathematical model of phosphorus transformations has been applied to a real set of physical, biological, chemical observation data in Lake Balaton. The model includes dissolved oxygen and five phosphorus forms in water environments: phytoplankton phosphorus, bacterial phosphorus, dissolved inorganic phosphorus, dissolved organic phosphorus, and unliving particulate phosphorus, and also three phosphorus forms in interstitial water: inorganic, organic, and particulate phosphorus fractions. The purpose of this report was to present the best possible calibration between existing observation data from 1977 and model output. This is one of the important steps that must be performed before application of the model for prediction and management purposes. Hypothesis about three populations of phytoplankton give a model output that agreed reasonably well with the observation data for total P, dissolved P, dissolved organic and inorganic phosphorus, particulate organic phosphorus, and phytoplankton chlorophyll "a" in all basins simultaneously. This provides indirect evidences that the model considered is a reasonable representation of a complex ecological process in phosphorus transformation and phytoplankton dynamics in Lake Balaton