Water protection is one of the most all-round regulated areas of the EU environmental control. In order to forecast the state of water ecosystem, it is necessary to evaluate changes in water quality. In order to evaluate the influence of changes in the land-use structure on Lithuanian fluvial water, the article looks into the most characteristic Lithuanian watersheds. To reflect the links between the water of all rivers in Lithuania and the land-use structure of their riverside watersheds, there were chosen eight watersheds of Lithuanian rivers as the object of research with the focus on the characteristics of biogenic substance migration in their water-sheds. Cartographic material CORINE (scale 1: 100,000) and CORINE land cover (1995) were used for evaluating changes in the land-use structure. Research contains land-use structure analysis on two spatial levels: 1) 200 m zone from the river bed; 2) the entire watershed. A multiple dispersive analysis between nitrate concentrations and the structural elements of land-use has showed that reliability is absent although correlation coefficients exceed 0.63. This may be explained by a rather complex nitrogen circulation and its components including fixation (biologic and industrial), assimilation, nitrification, denitrification, inflow with rainfall, elution etc.

Article in Lithuanian