SERBIAN AND CANADIAN WATER QUALITY INDEX OF DANUBE RIVER IN SERBIA IN 2010

This paper aims to assess water quality of Danube River in Serbia for 2010. Two methodologies were applied for this purpose: Serbian Water Quality Index (SWQI) and Canadian Water Quality Index (CWQI). WQI value is dimensionless, single number ranging from 0 to 100 (best quality) derived from numerous physical, chemical, biological and microbiological parameters. SWQI was mainly good and very good. This methodology includes parameters for assessment of organic loading, but does not involve parameters of heavy metals concentration. For that purpose CWQI was used. Besides overall, CWQI was calculated for following uses: aquatic habitat, drinking, recreation, irrigation and livestock. Overall CWQI was marginal and fair, which was equivalent with poor and good SWQI. CWQI methodology showed increased concentration of copper in all cases which affected overall water quality and aquatic habitat while increased turbidity in many cases had negative influence on drinking water. Differences between SWQI and CWQI resulted from different methodology: different methods of calculation and parameters. In order to get more comparable results it is necessary to develop unique WQI methodology.