Long-term changes in the eco-chemical status of the Danube River in the region of Serbia

The Danube River is an international river, one part of which flows through Serbia. The eco-chemical status of the Danube River is a constant topic of interest both at the local level, in each country through which the Danube flows, and at the international level. General interest to ensure the sustainable and equitable use of waters and freshwater resources in the Danube River Basin led to the development of a system for monitoring the river, which has produced data sets of its eco-chemical status. These have been collected over many years in Serbia; however, the present interest was focused only on the period from 1992 until 2006, i.e., a 15-year period. The process of defining trends of selected eco-chemical parameters, using linear regression analysis with a defined level of significance, and their separation from natural variability is of the highest importance for defining the changes in the water parameters. Through them, the fate and behavior of the eco-chemical parameters of the Danube in Serbia can be recognized and the prediction of their trends in the near future can be attempted. The obtained results revealed a constant improvement and acceptable trends of the eco-chemical status of the Danube River, as well as, substantial differences in the quality of the inflowing and out flowing water.