title: Researches of the chemical composition of surface water in Ukraine, 1920-2020 (review)
abstract: The development of researches of the chemical composition of surface waters (rivers, lakes, reservoirs and ponds) is due to problems that are solved at one stage or another in the development of the country’s economy and are related to water quality issues. Depending on the tasks set during hydrochemical researches, attention is paid to a particular group of chemical components in water: 1) the main ions and their total amount (water mineralization); 2) dissolved gases; 3) biogenic elements; 4) 
journal: Journal of Geology Geography and Geoecology