No 3 (2025)

Late orogenic structural plan was distinguished with orotectonic method in addition to two well-known structural plans, i.e., late geosyncline and early orogenic, in the territory of Eastern Dagestan, which is the western near-orogenic flank of the Tersk-Dagestan foredeep. This structural plan unites the youngest neotectonic structures and determines the main features of the modern relief. It is characterized by the predominance of blocky structures associated both with the activation of arched orogenic uplift and with the taphrogenic influence of developing Caspian depression. The block structures of this structural plan determine localization of modern exogenous processes including geohazards and disruptures, which must be taken into account upon construction, irrigation and other economic activities. Therefore, the study of this structural plan is not only of theoretical, but also of practical significance.

A new methodological approach to the quantitative assessment of infiltration water exchange in poorly drained river basins is presented. Its implementation is demonstrated by the example of a numerical geofiltration model (NGFM) of the watersheds of poorly drained Lesnaya and Mukhavets rivers, which occupy the bulk of the Brest hydrogeological basin area (BHGB). NGFM of the Lesnaya and Mukhavets river catchments was created on the basis of licensed ModTesh software of Geolink CJSC. The model calibration consisted in obtaining a preset value of groundwater flow into rivers and matching the model and actual groundwater heads for the summer-autumn season by determining the infiltration recharge intensity (IRI) and the conductivity of subsurface sediments. Satisfactory results were obtained after dividing the model inflow into blocks with the groundwater discharge into rivers and the infiltration discharge through the aeration zone. To estimate the resulting infiltration recharge (IR), we used a technique consisting in setting a fictitious boundary of the third type above the groundwater aquifer in the form of a low permeable layer and a reservoir, in which the water levels of groundwater aquifer are duplicated. Application of this technique resulted in the minimal discrepancy between the values of model and actual groundwater heads (below the error level in the initial data). A quantitative assessment of the long-term resultant IR is given, which is an integral indicator of the modern vertical groundwater exchange with the environment. The change in the resulting IR value by the catchment area of Lesnaya and Mukhavets rivers is shown as a separate map. The components in the balance of ground-, interstratal and surface water in the catchment areas of the Lesnaya and Mukhavets rivers have been assessed quantitatively, taking into account the yearly changes in IRI.

Based on a model experiment involving hydrocarbon contamination of sandy soil, the response of higher plants to varying concentrations of the pollutant was studied during phytotesting. The experimental research aimed to assess the acute toxic effect and was conducted using the plate phytotesting method, with white mustard (Sinapis alba L.) as a dicotyledonous test crop and sweet sorghum (Sorghum saccharatum L.) as a monocotyledonous test crop. It was established that the plant response to hydrocarbon contamination (diesel fuel) in sandy soils is nonlinear, with a pronounced toxic effect at low concentrations (1—2 wt. %) and reduced toxicity in the range of 3—5 wt. %. It is hypothesized that this effect may be due to the organic nature of hydrocarbon contamination and the presence of available nutrients within the tolerance range of the higher plants used. These assumptions were supported by the results of assessing changes in the total microbial population in contaminated sandy soils during phytotesting, where an increase in the number of active microbial communities was observed at low diesel fuel concentrations (1—3 wt. %). The metabolic products of these microorganisms may have a pathogenic effect on the developing test crops. The identified patterns will further enhance the efficiency of the biological stage of reclamation carried out in areas with hydrocarbon-contaminated sandy soils.

The object of research included surface- and groundwater in the area of the Kholboldzhinskoe brown coal deposit located in the strand of Lake Gusinoe, which is of great fishery and recreational importance for local population. The deposit was developed for 38 years and occurred in a mothballed state for 24 years. The purpose of study was to reveal the regularities in changing chemical composition of surface- and groundwater during the field development and long-term storage of mining waste. The tasks were to determine the water volume contained in mine workings and to find sources of its inflow into the quarries; to study the regularities of groundwater formation within overburden dumps; to describe the chemical composition of surface- and groundwater and to compare them with the maximum permissible values for fishery water. Field and laboratory studies were carried out to solve the tasks set. Observation wells were drilled at the foot of overburden dumps to monitor the groundwater table and its chemical composition. The trace element composition of water was studied using the inductively coupled plasma method (ICP MS) on the quadrupole Agilent 7500 ce mass spectrometer. It was found that the groundwater flow direction changed in the technogenically disturbed area to discharge into the mine workings. The total volume of quarry water reaches 2 million m³. In technogenic water bodies, water of several aquifers mixed. Concentrations of molybdenum, copper, zinc, and strontium were found to exceed significantly the MPC for fishery water. Mine development has increased rock permeability, and a significant portion of surface runoff has been turned into underground runoff. Precipitation falling in the mine working area infiltrates through overburden dumps, interacts actively with weathered coal and host rocks, and dissolves toxic components. The groundwater flow discharging into Lake Gusinoe shows high levels of chemical elements of the second, third and fourth hazard classes. Among them, molybdenum, lead, strontium, tungsten, copper, zinc, nickel, cobalt, manganese, iron, aluminum, phosphorus are detected. To prevent contamination of Lake Gusinoe with liquid waste from coal mining, it is necessary to rehabilitate overburden rocks and eliminate the threat of water outbursts from technogenic water bodies. To reduce environmental hazard in the area, it is necessary to pump technogenic water into the quarries with the surface level below Lake Gusinoe.

Based on domestic and foreign publications, the classes and main characteristics of persistent organic pollutants (POPs), including dioxins and furans (PCDD/Fs), their formation and content in bottom ash and fly ash (FA) from the combustion of municipal solid waste (MSW) are described. The role of total organic carbon content as a key parameter influencing the formation of PCDD/Fs during the combustion of MSW is considered. Modern incineration technologies that prevent the formation of POPs and methods for detoxification FA before disposal are presented.

Hyperspectral imaging has proven to be a powerful tool in environmental applications. This review article focuses on implementation of noncommercial hyperspectral data in soil property predictions suitable for engineering geological applications. Prior attention has been given to spectroscopic processing and further data analysis in case studies of mineral composition, grain size, soil moisture and soil organic carbon. We considered PRISMA, EnMAP and DESIS perceptively to be the most suitable sensors for soil mapping according to the specifics of Russian environmental research, described modern pre-processing techniques and use-cases for hyperspectral imagery in soil studies. Pros and contras of spectroscopic approaches are discussed from engineering geological point of view. We concluded that the main problem preventing the local further development of spectroscopy is lack of soil samples for Russian territory available in published spectroscopic libraries. Several points were raised regarding orthorectification and atmospheric corrections, i.e., the need for data of high resolution and requirement of processing improvement might be still a problem for soil applications. On the other side, large amount of data available for scientific use, high accuracy and spatial resolution of hyperspectral imagery stimulates us to find a solution of mentioned problems. This work tends to demonstrate advantages of spectroscopic approaches to direct spectral data interpretation and it is aimed at drawing more attention of researchers in engineering geology to spectroscopic approaches.