System dynamics of eutrophication processes in lakes

Eutrophication is the phenomenon observed in the bodies of water that receive large influxes of nutrients due to agricultural runoff or urban waste disposal. It is characterized by blooms of either green or blue–green algae (often noxious smelling) and by a drastic reduction in dissolved oxygen and often makes it impossible for many species of fish and zooplankton to live in the water. The objective was to examine the effects of eutrophication on plankton seasonal dynamics. Simulation models have been used as a primary tool in the study of eutrophication in lakes. Many eutrophication models have been developed both to predict the effect of nutrient additions on lake biota and to examine how effective various nutrient diversions alternatives might be for improved water quality. Systems dynamics was studied using the model, which is expressed as a series of four differential equations as its state variables for the rates of change of phytoplankton, zooplankton, nitrogen and phosphorus. Influence of the phosphorus concentration on eutrophication was treated and studied as the one of the most important processes in the lake ecosystem.