Water Quality in Watercourses of the Transboundary Narva River Basin

A procedure has been developed for the assessment of transboundary river water quality. The procedure is based on the calculation of the chemical index and classification of water quality. The quality of river waters is assessed by measuring a set of chemical parameters in water samples, followed by data representation in the form of the chemical index CJ which characterizes generalized water quality. A classification system has been proposed for the estimation of contamination of transboundary water bodies on the basis of a "broken bar" model. Using the developed procedure, year-to-year, within-year, and seasonal dynamics of water quality in watercourses of the transboundary Narva River basin have been determined.