SIMULATION OF THE IMPACT OF FERTILIZER DOZES ON NITRATE CONCENTRATIONS IN THE STREAM

One of the requirements imposed by the Water Framework Directive 2000/60/EC is to analyze and predict long-term evolution of surface water quality parameters. During a 20-year period (1987–2006), concentrations of nutrients were studied in three model microbasins of the experimental Mostenik basin (Institute of Hydrology) in Central Slovakia: 1. Rybarik (agricultural), 2. Lesny (forested, hornbeam), and 3. Cingelova (forested, spruce). This study deals with a suitable stochastic Seasonal Auto-Regressive Integrated Moving Average (SARIMA) models that were used to simulate monthly nitrate concentrations in the Rybarik stream. Two regressors (fertilizer dozes and discharge) were added into the models to simulate the impact of fertilizers on nitrate content in the stream water.