Changes in Water Quality in the Upper Wisla (Vistula) River Basin

The aim of the study is the analysis of water quality changes in the Upper Vistula. The issue of water quality is important to Poland, where water resources are poorer than in many countries of the European Union. The study spans the period before and after political transformation in Poland, which significantly altered its economy. Changes in indices of water pollution were investigated for 4 monitoring sites. The results demonstrated that poor water quality in the Vistula improved significantly near the end of the 20^th century, as the result of closure of many industries and improvement of sewage treatment.