Seasonal changes in the macroelement content in the water of the Rawka river in 2003-2009

Monitoring the quality of water for a long period of time is the only way to objectively assess the influence of human activity on the natural environment. Evaluation of water quality is not only of cognitive value but also of economic value, e.g. for industrial or agricultural purposes. Both environmental and human factors may significantly change the quality parameters of river waters. The aim of the experiments was to assess the variation in some chemical parameters describing the quality of the water of the Rawka river over a period of the last seven years (2003 - 2009) from the point of view of its suitability for irrigation. The analyses showed a relatively low salinity of the water but with a steadily rising trend. The increase in water salinity was caused by the rising levels of Mg, Na and Cl. No increase in N, P and K content in the water does not confirm the common opinion of the devastating influence of agriculture on the river’s water quality. Moreover, the results of this seven – year - long experiment showed that the Rawka’s water is still of high value for irrigation purposes