Ecological and hydrogeological factors of qualitative composition destabilization of drinking groundwater within the central part of DDAB

Abstract

Formulation of the problem. The paper is devoted to a topical environmental theme – a study of the destabilization of drinking groundwater quality in the conditions of modern intensive technogenesis of geological environment. The purpose of the article is 2 components of a study of the groundwater quality deterioration of buchak-kaniv aquifer: - an identification of the ecological and hydrogeological factors of influence on the water qualitative composition; - an ensuring of the environmentally safe use of groundwater. Materials and methods. The research is based on an analysis of the results of over 700 groundwater chemical analyses of the target aquifer within the region. The chemical researches have been carried out during the period of active man-made pressure on the geological environment of studied territory (1960-2015). The available current data of geological, ecological and neotectonic conditions of studied area have been also used. The following methods of obtaining, processing and interpretation of necessary ecological-hydrogeological data have been used in the paper: field, chemical-analytical, comparative and graphical methods. A number of the common research methods have been used for the information processing – an analysis, a synthesis, a systematization, a classification, a modeling. The mathematical and statistical methods have been also used in the processing of received large data set. The interpolation and analogy methods have been used to simulate changes in the groundwater hydrochemical features using MapInfo Professional 10.0. Results and scientific novelty. For the first time on the basis of analysis of geological, ecological-hydrogeological and neotectonic conditions of region, the factors of influence on the qualitative composition of groundwater at the buchak-kaniv water intakes were revealed. On the basis of these factors – the priority indicators of buchak-kaniv aquifer water quality for its systematic hydrogeochemical monitoring under the infiltration of pollutants from the surface and their inflow from below in the zones of influence of tectonic structures have been proposed. For the first time a direct positive correlation between a change of the content of characteristic indicator elements of influence on the ecological-hydrogeological state of groundwater (mineralization, Cl-, F-, Fetotal, Br-, B3 +, J-) and the value of total water withdrawal in the zone of direct influence of tectonic faults of East-Poltava tectonic structure has been found. An approach for the ecologically safe use of target aquifer waters within the buchak-kaniv water intakes of Eastern Ukraine, which is based on the established correlation between the factors of influence and the qualitative composition of waters, has been developed. Practical significance. Due to an approbation of the proposed water quality control system at the Poltava water intakes network, which is strategically important within the region of research, an optimization of the total water withdrawal at the water intakes has been justified (the recommended limit is 50-60 thousand m3/day). The perspective areas for location of new water intakes within a 40 km radius around Poltava city have been identified (a total area – 750 km2). The estimated resources of drinking groundwater (54.5 thousand m3/day) have been calculated. Due to the using of these resources it is possible to gradually replace the current water supply of urban agglomeration with high-quality groundwater.