IMPACT OF ATMOSPHERIC PRECIPITAIONS ON THE SURFACE WATER CHEMISTRY IN MOUNTAIN AREA

The aim of this study is to establish the degree of impact of precipitations’ chemical composition on the chemical composition of high-mountain (over 2000 m a.s.l.) rivers with snow-rain feeding. The contribution of the hard and liquid rain to surface water composition is investigated individually. The surface water quality in the environs of Mount Cherni Vruh - Vitosha Mountain, Bulgaria ? is determined. A temporary local monitoring network for surface water quality was established in the examined period (2004-2010). Precipitation samples are taken on Mount of Cherni Vruh ? one of the stations of the precipitation chemistry network. The findings present the background levels of the studied hydrochemical parameters for surface water. The predominant anions in river water are hydrocarbonates and sulphates while the predominant cations are calcium and sodium. The measured pH values suggest the pure precipitation’s influence on river water in terms of acidity. It is perceivable that the majority of the nitrate concentrations in river water originate in the precipitations.