The analysis of time variability of riverbed elevation recorded at eight cross-sections of the Upper Vistula River is presented in the paper. The variability is analyzed on the base on the observed low annual water stages and the cross-sectional geometry variation observed over decades. Furthermore, the analysis of riverbed changes in the years 2001 - 2011 was done in 16 cross-sections located between the Koło and Zawichost gauging stations. Based on the analyzed changes in the riverbed elevation of the eight tested gauging stations it should be noted that since the beginning of the observation period, that is from about the beginning of the 20th century to the mid 1960's, in the Upper Vistula River riverbed erosion can be observed with a slight tendency for accumulation. As a result of technical regulations of the river channel of the Vistula River from km 247 +000 to 295 +000 carried out in the years 1975 to 1982, intensive processes of riverbed erosion has occured. In most of the 16 profiles it was found that in the years 2001-2011 the river channel was deepened. The occurrence of local riverbed deepening at the river banks was also observed. ...
The paper presents change of water quality within Vistula River in the city of Warsaw. Water samples for analysis were taken from four different measurement points in the period from February to June 2016. Based on the results of laboratory studies it was demonstrated that the Vistula River in Warsaw is exposed to the input of pollutants contributing to increase the salinity, especially in winter and early spring. The concentration of both chlorides and sulphates were highest in February and was decreasing in subsequent months of the year. At the same time it has been shown that during the entire study period the concentration of Cl- ion exceeded the limit values for water quality II class in Poland. While the SO42- concentrations in water samples taken in the winter months (February-March) exceeded the limit values for the second quality class, in April, it was within the acceptable range for II class water quality, and in May and June does not exceed the value referred to as standard for I class of water quality. Based on the analysis of indicators of nutrients (N-NH4, N-NO3, Ptot.) it was found that the Vistula is not exposed to eutrophication due to their low ...
