Simulation of the impact of pollution discharged by surface waters from agricultural areas on the water quality of Puck Bay, Baltic Sea

Abstract

The paper presents the analysis results of the impact of pollution discharged by surface waters on the quality of the Puck Bay waters. Puck Bay is part of the Gulf of Gdansk and belongs to the Baltic Sea. The analysis was carried out using mathematical modeling. A numerical model of part of the Gulf of Gdansk was achieved, taking into account the current bathymetry and the shoreline shape. The pollutants inflow was assumed point-by-point at the mouth of the main watercourses: Plutnica, Gizdepka, Bladzikowski Creek and the Reda River. The hydrodynamic conditions in the Bay were adopted for several scenarios regarding wind speed and direction. In order to determine the velocity distribution, the Ekman model—dedicated to shallow coastal waters—was used. The spread of pollutants in the Bay’s waters was determined by solving a two-dimensional, partial differential, advection–dispersion equation describing the migration of a non-degradable dissolved matter. The finite volume method was used for the solution. As a result, the extent of pollution in the Puck Bay area was obtained in relation to Natura 2000—the European Union’s protected areas. Visible is the necessity of integrating these conclusions into measure aiming at the mitigation of eutrophic processes in the Baltic Sea. The results of this research may be extended to serve other bay regions adjacent to similar substantial agricultural activities.