Developing a Dynamic Simulation Model for Phosphorus Cycling in Lakes ‎(Case Study: Lake Ontario)‎

Food cycle creates a mechanism through which nutrients and other components of life are available for the living organisms. Improper function of the cycle may lead to disruption in the life cycle of organisms. In this paper، the dynamic flow of phosphorus، which is essential for plant growth، was studied considering three state variables: productive organisms (organic phosphorus)، dead organisms (organic phosphorus) and inorganic phosphorus. According to the three state variable’s feedbacks، phosphorus and phytoplankton simulation model was developed using the system dynamics approach and considering governing equations، feedback loops، and input and output streams. The behavior of each state variable was evaluated during a year for Lake Ontario. The result revealed that the model benefits from the desired performance in simulating and estimating the variable concentrations. It can be clearly seen that stratification and completely mixing of the lake during two periods (day 100 to 158، and day 315 to 335) have paramount impact on the variable concentrations.