The springs of the North-east of the East European Plain: Headlands of the river network formation

This study examines the impact of spring water inputs on river water quality in the northeastern sector of the East European Plain, with specific focus on the Chuvash Republic. Ecological assessment of river valleys and springs was conducted through two complementary approaches: visual evaluation of landscape transformation intensity and comprehensive chemical water analysis. River valleys in the study area exhibit significant anthropogenic modification, attributable to extensive settlement coverage (up to 21% of total area) and predominant pastureland use. Spring-adjacent areas demonstrate substantially lower anthropogenic pressure. Chemical analysis reveals single-component point source contamination in spring waters, with affected springs representing less than 5% of sampled locations. In contrast, river water samples display multicomponent contamination in over 70% of cases, with optimal chemical composition observed exclusively in forested watersheds. The findings indicate that water quality degradation in small rivers of the Chuvash Republic primarily results from industrial effluent discharge, agricultural runoff, and proximate livestock operations. No significant correlation emerges between spring water characteristics and river water composition, suggesting limited hydrological connectivity between these systems under current land use condition.