Hydrologic conditions for chemical composition of the Siberian river waters

The influence of hydrologic conditions on the Siberian river waters chemical composition, their spatial and temporal changes are analysed. The dependencies between the hydrochemical and hydrological parameters are determined. It is shown that: 1) many hydrochemical parameter changes are defined by lognormal probability distribution; 2) variability of the chemical composition and elevated concentrations of some substances will be more likely to occur in the inter-annual and intra-annual runoff variability; 3) the main features of the water chemical composition are formed at the stages of the slope, subsurface and underground runoff formation.