Water quality evaluation of the Danube River basin in Ba?ka (northern Serbia) using multivariate statistical techniques

The study aimed to analyze changes in water quality based on ten physicochemical parameters for the Danube River in Backa. Data from three profiles over a twenty-year interval were used and processed using multivariate statistics. An ANOVA indicated that the quality of surface water is mostly at a satisfactory level. Sufficient amounts of dissolved oxygen indicate a favorable aeration regime. The surpassing of the annual and monthly values of suspended solids was recorded for all profiles (especially in summer). The summary results show that most parameters, except for suspended solids, are within the allowed values for water quality Class II. A Pearson's correlation test indicates a moderate to weak correlation of the analyzed parameters. A PCA analysis determined the influence of (a) eutrophication processes; (b) ecological factors; and (c) concentrated sources of pollution. Changes in the Danube's water quality, primarily increased concentrations of suspended solids, can exert a limiting influence on some economic activities and their planning.