Аннотации:
© The Authors, published by EDP Sciences, 2019. The upper part of the section of the Tatarstan Republic is composed of polyfacial Middle-Upper Permian, Mesozoic, and Pliocene-Quaternary sediments. Surface and ground water are characterized here by wide variability of composition and salinity. These variations are determined by a complex of natural and technogenic factors. The most important natural factor is the interaction of precipitation and their derivatives with soils and rocks of the section. Water extracts from the main soil varieties were analyzed on the basis of distilled and thawed snow water in order to evaluate this interaction. The compositions of water extracts are compared with the compositions of the least mineralized spring waters. The components which are supplied in the underground hydrosphere by the soils are determined. It is shown that 50-80% of the ground water composition, which generate outside the zones of anthropogenic impact, is determined by the interaction of precipitation with the soil cover.