Aksem S. The estimation of sulfate karst influence on natural water chemical composition (on the example of southern part of Western-Ukrainian forest-steppe province).

The topic of the thesis refers to investigation of the karst influence on natural water chemical composition in the gypsum-anhydride rocks (Middle Miocene) of the western areas of Ukraine. Implementation of uniform improved constants for the mass transfer coefficient and unify methods of calculation of saturation sulfate index forms the background for comparison of natu-ral water aggressiveness in different karst areas. Improved and adopted for Western-Ukrainian areas conditions the set of field investiga-tions, analytical calculation of thermodynamic parameters and modeling of karst development rate in sulfate rocks allowed investigate and compare gypsum-anhydride rocks solution rate on uniform basis. The regularities and quantitive characteristics for gypsum-anhydride rocks solution rate in different conditions of water-rock interaction are determined. Using compiled database "Gypsum karst of Western Ukraine" on hydrochemistry and karst the information as to karstology, hydrology, hydrochemistry, hydroecology were processed, analyzed and highlighted in the thesis. The influence of sulfate karst on water and chemical surface run-off of tributaries in the upper part of Dniester-river was estimated. Application of proposed complex technique of field karst investigation and processing data by computer code improves reliability and accuracy of prognoses, estimations and assessment. The economic saving was achieved due to shrinkage experimental works. Key words: sulphat karst, groundwater formation, water drain, chemical drain, Dnestr.