GEODYNAMICS

Abstract

The aim of the research is to substantiate the scientific foundations of an integrated approach to solving environmental and geological problems related to groundwater salinization in the Kalush mining region; quantitative evaluation of the dynamics of such salinization and its relationship with the river system based on geochemical and geophysical observations. The relevance of the research is determined by the need to solve the following tasks: 1) identification of the sources of the groundwater contamination; 2) determination of saline areas, including settlements within which drinking water horizons become unsuitable for the direct use; 3) characteristics of the dynamics, that is, the degree of salinity and the rate of its changes in space and time; 4) determination of the danger to the operation of water intake facilities; 5) determination of the risk of contamination of the river basin. The methodology consists in establishing the correlation between hydrogeochemical and electrometric observations, as well as determining the transition patterns from measurements of electrical resistance to the groundwater salinity. It also includes creating spatio-temporal models of groundwater salinity dynamics and assessing the risks of surface watercourses contamination taking into account its main sources and providing initial data for making management decisions. With the help of the hydrogeochemical observations (the groundwater mineralization) and electrical exploration (measurement of electrical resistance), correlations were established between the geophysical characteristics inherent in the aquifer and the groundwater mineralization. As a result, this made it possible to concretize the sources and determine the area and degree of salinization according to the planar geophysical surveys. Regime observations allowed us to establish the movement direction and speed of the salinity front. The obtained quantitative characteristics of the salinization dynamics of the aquifer allowed calculating the contamination risks of the Limnytsia and Dnister Rivers. The scientific novelty consists in the further development of the methods for assessing underground mineralization based on the results of geophysical research, including the method of electrical exploration. For the first time, spatio-temporal models of the groundwater mineralization dynamics in the territory of the Kalush mining region (KMR) were created. In addition, the assessment of the risks of the surface watercourse contamination (the Limnytsia and Dnister Rivers) was given, taking into account the main sources of contamination within the KMR. The application of the obtained results makes it possible to quickly research the areas associated with probable contamination of the territory, to provide initial data for further planning and management actions. A reliable forecast allows envisaging the measures for reducing the environmental load on the aquifer, which is the only drinking horizon for the town of Kalush.