Kononenko A. Factors of ecological and hydrogeological evolution of the chemical composition of groundwater of the marl-cretaceous aquifer of the Dnieper-Donets depression

The dissertation is devoted to the study of the peculiarities of changes in the chemical composition of groundwater of the marl-cretaceous aquifer in the different geological conditions. The study of these changes carried out on the example of the three most indicative water intakes of the eastern part of the Dnieper-Donetsk depression: Svitlychansky, Zhytlivsky and the complex of marl-cretaceous water intakes of the Kharkiv region. In this work the main preconditions for reducing the quality of drinking groundwater of the water intakes under investigation are based on the analysis of their geological, hydrogeological and ecological peculiarities of exploitation. It is proved that the quality of groundwater intakes simultaneously affects both the geological conditions of the research area and the technogenic load. According to the correlation analysis, for Zhytlivsky water intake, a direct correlation is founded between the change in the mineralization of groundwater from the quantity of water sampling in the zone of influence of regional tectonic disturbance. It is determined that the main changes in the qualitative composition of the underground waters of Svitlychansky water intake are caused by the long-term discharges of highly mineralized chloride waters of the "Proletarskaya" mine in the Svetlichna strand. It is founded out that for the complex of marl-cretaceous water intakes of the Kharkiv region, the decline in the quality of groundwater is due to the flow of man-made pollution from the surface as a result of the processes of their infiltration under conditions of insufficient natural protection of groundwater. On the basis of the researches and established regularities, measures and recommendations for stabilization of the quality of drinking groundwater at the water intakes of the eastern part of the Dnipro-Donets depression are developed: a scheme for the rational allocation of new intakes within the sandy river terraces of the Siversky Donets River is proposed, "A method for increasing groundwater resources on plane water intakes" and justified optimization of water selection at Zhytlivsky water intake. Key words: afforestation, chemical composition of groundwater, correlation analysis, cretaceous water intakes, hydrogeological “window”, man-made factor, marl-cretaceous aquifer, radiation risk, radon, sandy river terraces.