Snizhko S. The theory and methods of the regional hydrochemical systems analysis

New scientific, theoretically and methodologicalally proved approach to study of spatial - temporary fields of chemical substances in natural waters is stated. The concept on specific natural formation named as hydrochemical system (HCS) is entered and formalized in hydrochemical science. The basic properties and functions of hydrochemical systems is investigated, them typification is executed and it is offered hierarchical. Сlassification of vertical structural levels of hydrochemical systems in view of features of interrelation of various types of natural waters іs developed. Мethodology of research HCS, focused on applied application іs created. Сomplex of researches of regional hydrochemical systems of natural waters of Ukraine with the purpose of approving of methodological development is executed.