Exploring the trend effects of diffuse anthropogenic pollution in a large river passing through a densely populated area

The detection of non-point pollution in large rivers requires high-frequency sampling over a longer period time, which, however presumably provides data with spatial and temporal variance. Variability may mean that sets recorded upstream downstream from densely populated area overlap, suggesting at first glance the urban did not affect water quality. This study presents simple way to explore trend-like effects Danube based on varied strongly space time. For one year, biweekly was carried out city negligible emission untreated wastewater surrounding settlements, industrial agricultural areas.Although most values 34 examined physicochemical characteristics fell within range previously published for Danube, all parameters indicated unpolluted surface water, different quality revealed metropolitan each Since causing separation also differed time univariate tests consensus ordination were used determine which variables changed similarly during period. With this evaluation method, several diffuse pollutants anthropogenic origin contaminating long term identified, such as nitrogen, phosphorus, sulphate, chloride, potassium vanadium. results demonstrated can be detected even river, where measurements vary