Features of infiltration water intakes operation (on example of the Mokhovsky groundwater deposit in the Republic of Khakassia)

Abstract

Relevance. The work is devoted to the study of the features of infiltration intakes operation in conditions of variability of groundwater supply. The paper considers the issues of the impact of climatic and anthropogenic factors on the nutrition of the operational aquifer of the Mokhovsky groundwater deposit. The intake is characterized by a mixed nutrition due to the formation of attracted resources from the Krasnoyarsk reservoir and from the underlying horizon of the Upper Devonian sediments. The dynamic balance between the sources of attracted resources is determined both by the productivity of wells and the changing distance of the reservoir coastline (feeding boundary) from the water intake wells. A consequence of balance redistribution in favor of deep nutrition is a change in the chemical composition of groundwater, which leads to an excess of the maximum permissible concentration in terms of total mineralization and hardness. The analysis of hydrogeological conditions makes it possible to assess the variability of groundwater composition under the influence of dynamically changing supply conditions of an operational aquifer. Aim. Quantification of influence of boundary conditions on the Mokhovsky productive horizon during replenishment of groundwater reserves; predictive modeling of the intake operation with variability in reservoir surface water levels; assessment of changes in groundwater composition under the influence of incoming waters from Devonian sediments and forecast of the deposition of secondary minerals on water lifting equipment based on the assessment of mineral equilibria. Methods. Decoding satellite images, hydrodynamic modeling, hydrogeochemical calculations with subsequent comparison of forecast results with real data from routine observations. Results and conclusions. It is shown that the decryption of multi-zone satellite images makes it possible to control the reservoir level regime and assess its impact on groundwater supply conditions due to surface sources. The results of the proposed forecasting scheme make it possible to assess the effectiveness of regulating the reservoir level regime due to the operation of hydroelectric power plants and identify the size of the supply zones of infiltration intakes. It is demonstrated that remotely obtained data can be used to substantiate the necessary sizes of finite-difference grids of hydrodynamic models. The results of numerical simulation of water intake operation in the Processing Modflow PC environment show the dynamics of changes in levels in the operational aquifer with changes in the reservoir surface water level. Evolution of the composition of the waters of the productive horizon was revealed under the influence of their mixing with the surface waters of the reservoir and the groundwater of the Upper Devonian sediments below, and the probability of the formation of secondary minerals on the water lifting equipment was estimated using the HydroGeo software.

Keywords

• remote sensing
• groundwater
• chemical composition
• infiltration
• mixing of waters
• physico-chemical and hydrodynamic modeling