Integrated Approach to the Evaluation of Chemical Dynamics and Anthropogenic Pollution Sources in the Sava River Basin

Abstract

A variety of approaches are presented to evaluating the geochemical dynamics and anthropogenic pollution sources of the entire Sava River Basin, a major tributary of the Danube River. The water chemistry is found to be controlled by the geological composition of the drainage area in the upper reaches of the river, influenced by agricultural activity and biological processes in the middle reaches, and related to industrial impact in the lower reaches. The Sava exported 1.9 × 1011 mol C year−1 as dissolved inorganic carbon (DIC) and emitted 2.5 × 1010 mol C year−1 to the atmosphere. Carbon isotope composition indicates that up to 42 % of DIC originated from carbonate weathering and 23 % from degradation of organic matter. Agricultural and industrial sources are shown by statistical analysis to contribute significantly to the increase in Na+, K+, Cl−, SO4 2− and NO3 − concentrations in stream waters. Nitrate inputs are controlled by land use, and the elevated isotope composition of nitrate at some sites is attributed to sewage and/or animal waste. Contamination of suspended particulate matter by selected elements (Cu, Ni, Zn, Cd and Pb) in the main channel of the Sava River is low, while higher concentrations were observed in the main tributaries (Una, Vrbas, Bosna and Drina) due to industrial, mining and smelting activities.