Potential factors of regional development of dangerous geofiltration processes of water use in underground water basins of Ukraine

Abstract

It is indicated that surface water resources under the conditions of growing technogenesis and the consequences of military actions (military, geochemical pollution of catchment landscapes, destruction of treatment facilities, etc.) are classified as polluted and dirty (IV, V quality class). Underground water resources of Ukraine amount to 22.5 billion m3, of which up to 70% are protected or conditionally protected artesian waters of drinking quality, the transition to the use of which determines the relevance of the article. The purpose of the article is to analyze the potential factors of regional development of dangerous geofiltration processes of water use in underground water basins of Ukraine. The scientific novelty of the article lies in the assessment of the degree of influence of the complex of dangerous lithodynamic processes (HLDP), which have a hydrogeofiltration origin, on the qualitative characteristics of groundwater, the stability of the upper part of the rock massif, and the safe operation of water intake facilities. Practical significance. It is shown that with any scheme of depression funnel formation, the diffusion-convective movement of salts and microcomponents from the pore solutions of the poorly permeable (separating) layer is a stable spatio-temporal factor affecting the hydrogeochemical composition of water in operational aquifers. It has been proven that the hydrogeochemical evolution of the composition of water at most water intakes in Ukraine requires changes in approaches to the justification of well location schemes and the amount of allowable decreases in levels in operational horizons. It is estimated that engineering-geotechnically significant filtration compression of the aquifer occurs when the level drops by tens of meters or more. The results of spatio-temporal monitoring of filtration and compression subsidence of the earth's surface in the areas of depression funnels of water intakes and drainage and drainage systems of quarries and mines on the territory of Ukraine indicate that, in general, the amount of subsidence of the earth's surface is correlated with a decrease in the level in the operational aquifer, and in in most cases it is 1.0-2.5% of its value. It has been established that the subsidence of the earth's surface in the zones of depressions of underground water intakes is often accompanied by flooding and waterlogging of the territory, deformations of buildings and structures of engineering communications. It is stated that the active role in the development of the suffusion process during the operation of water intakes and drainage systems is played by the interlayering of fissured (crack-karst) sandy, multi-grained aquifers. This contributes to the formation of zones of increased hydraulic gradients and accelerated movement of hydrogeofiltration flow at the contacts of cracked and sand-dust layers and, as a result, activation of suffusion along the cracks. Calculations prove that the dangerous development of the suffusion process in the near-filter zone of the production well on the aquifer in multi-grained sands reaches 10-15 m. In the central zone of the depression funnel of a group or linear water intake, under the condition of the interaction of local well depressions, the distance of the development of suffusion deformations of the earth's surface increases significantly (up to 3-5 times) and worsens the engineering and geotechnical stability of production wells, pumping equipment, etc.