APPLICATION OF AN INTEGRAL METHODOLOGY IN DETERMINING TMDL FOR DISSOLVED OXYGEN IN THE BEČEJ-BOGOJEVO CANAL

Water quality (WQ) in the canal network in Vojvodina is not satisfactory. The most important WQ parameter is the concentration of
dissolved oxygen, which indicates suitability for life of aquatic organisms. The reach of Bečej-Bogojevo canal has been chosen since it receives seriously polluted water from the Vrbas-Bezdan canal. In the research an integral methodology has been applied consisting of WQ modeling using QUAL2K, Geographic Information Systems (GIS) mapping of spreading of dissolved oxygen concentration and calculating Total Maximum Daily Load (TMDL) values of polluting substances. The calibration of the model has been conducted using the data of WQ parameters obtained from field work, previously imported into GIS database. Besides, using data on concentrations of polluting substances from the cadastre of polluters a few simulations has been conducted for various scenarios and as a result GIS maps have been obtained showing changes in concentrations of dissolved oxygen along the reach. Finally, the TMDL values of major polluting substances affecting the concentration of dissolved oxygen have been determined.