EVALUATION OF POLLUTING SOURCES AND SELF-CLEANING ABILITY OF WATER FLOW IN RELATION TO LANDUSE

The aim of our research is to confirm or refute the hypothesis, which says that agriculture is the main source of surface water pollution. Nowadays, when more than 82 % of the Czech population is connected to public sewerage system, it is assumed, that the wastewater has not a significant impact on the quality of surface water, as there are waste water treatment plants and similar facilities for cleaning the sewage. Thanks to a detailed field survey and regular sampling followed by laboratory analysis of water from selected streams in southern Moravia and the Highlands it was found although municipalities are connected to the public sewerage system, which brings the sewage water into the treatment plants, deteriorating the quality of the water flow right through the village. The results of laboratory analyses of water from the monitored flows show the process of self-purification, they are seeing a significant decrease in the concentration of certain substances by water flow through the selected sections of land use. On the other hand, in urban areas or flow through the arable land the water is enriched by pollutants, this is on many places evidenced by developing of undesirable algae.