Water is a nonrenewable resource, and its unsustainable use almost everywhere has led to a decrease in water quality. The development of water quality indices and the introduction of indexing methods used in assessing the quality of surface waters (pollution) are particularly relevant in recent years. As a result of anthropogenic pollution of the aquatic environment, the entropy of the system changes, which is not always taken into account in hydrochemical studies. This chapter analyzes dozens of freshwater quality indicators existing in science literature and presents the advantages of the water quality indicators developed by the author and colleagues: the geoecological evolving organized index (GEVORG), and the Armenian Water Quality Index. Water quality analyses have been tested for most of the rivers, reservoirs, and lakes of Armenia. It was found that the Armenian Water Quality Index has a linear relationship with most water quality indexes, and an inverse relationship with the Canadian Water Quality Index. The quality of river and reservoir water has been assessed according to the new standards for background concentrations.
Part of the book: Inland Waters