Problem of ecological safety of aquatic environment in conditions of anthropogenic eutrophication

The state of any aquatic ecosystem, its trophic level, pollution degree and other constituents of environmental monitoring are reliably characterized by means of studying and monitoring the species composition and the number of planktonic algae. The most typical negative anthropogenic impact on the aquatic environment is drastic propagation of phytoplankton, called ''algal bloom''. It is caused mainly by the flow of nutrients into the water, which stimulate the intensive propagation of algae. Another factor that influences phytoplankton propagation is temperature. In this regard, the important question is the effect of temperature on the dynamics of phytoplankton expansion in aquatic ecosystems.The correlation analysis of algae propagation depending on the water temperature in a water intake (for example, the reservoir of the Teteriv River, a tributary of the Dnieper River) was made in the paper. The analysis indicated a significant influence of the temperature on algae propagation that allowed using trigonometric series in mathematical description of the dynamics of their propagation.According to the studies, an adequate mathematical model describing the dynamics of phytoplankton expansion in aquatic ecosystems was developed and its adequacy (model relative error) was estimated. The analysis of the relative error shows that the developed mathematical model adequately describes the dynamics of phytoplankton expansion in aquatic ecosystems. It should be noted that the proposed model can be simplified. However, this will increase the relative error, and, therefore, the model will not adequately correspond to the original.