No 1 (2019)

Evolution of tritium and beta contamination plumes resulted from radioactive waste leakage in the 1990s has been studied based on 40-year-long monitoring data at the site of radioactive waste (RW) storage. Localand regional-scale hydrodynamics are found to be the main features controlling the spreading of tritium contamination in the aquifer system, while spatial distribution of beta-activity plume is strongly restricted by sorption of 90Sr и 137Cs isotopes onto rock matrix. The study performed proves that groundwater system at the site is actually in the stage of rehabilitation from the «historical» contamination. Special complex investigation program aimed on examination of water accumulated in repository buildings and its interconnection with groundwater, demonstrated good isolation of the buildings from the surrounding aquifers and no evidence of RW release to the subsurface environment nowadays.

An urban area is the most important form of space-time interaction between society and nature. It is in the urbanized area that environmental problems are most acute. The developed Strategy of Ecological Safety of Russia for the period up to 2025 almost does not consider the role of geoenvironmental factors in the overall safety of the city. This article defines their place in the system of general ecological safety of urban areas. The structure of geoenvironmental hazards is introduced, and an example of their relationship is given. The algorithm of assessment is proposed and a version of the geoenvironmental safety system is developed for the urban area.

The paper deals with the assessment of stress-strain state variation in rock massifs upon the formation of displacement moulds and surface sinkholes in the undermined areas of Verkhnekamskoe potassium salt deposit in Perm krai, Russia. Engineering geological conditions, as well as natural and technogenic factors influencing the development of hazardous geological processes are described by the example of one typical site of the deposit. Methodical issues of the development of geomechanical model for this site and compilation of finite-element calculation scheme with selecting calculation parameters of rock properties and boundary conditions of the calculation area are considered. Regularities in the variation of stress fields and rock massif deformations upon cutting mines at one depth are considered. The possible mechanisms of deformation and destruction of karstified rock massifs upon the formation of technonatural sinkholes on the earth surface are described. The results of the study are significant for predicting hazardous processes and undertaking protective measures.

The transformation of oil hydrocarbons in groundwater is mainly related to the processes of biodegradation. At sites where residual crude oil or petroleum hydrocarbon fuel contaminants are present in the environment, biodegradation reactions result in the formation of partial oxidation products, i.e., metabolites. These transformation products are more soluble than the parent petroleum hydrocarbons, due to their greater polarity and corresponding low volatility. Transformation products from residual source zones are distributed in aqueous phase to form a plume of contamination in groundwater. The content of metabolites depends on the redox conditions and the presence of the terminal electron acceptors, as well as on the structure of the original hydrocarbon compounds. The article considers the conditions for formation of metabolites, their degradation, migration to groundwater and plume formation, toxicity of metabolites. Examples of modeling the migration of metabolites in the saturated zone are given.

The article deals with the present state of the formalized description of a 3-dimensional geological model with the consideration of the problems arising from the increase in scale and the transition from the geological bodies distinguished by stratigraphic principle to those identified by lithology-stratigraphic and engineering-geological divisions. An approach to solving these problems is proposed. It is shown that the problem of correctly determining the sequence of occurrence of lithological-stratigraphic subdivisions can be solved as a problem of topological sorting of vertices of an oriented graph. For the first time, the requirements for non-local alignment of geological sections are set.

The paper touches upon a very important topic, i.e., the interaction between a Man and Nature. Nature attracts people aesthetically, it symbolizes the triumph of life, love and inspiration. Nature makes a man more kind, happier, and spiritually richer. At the same time, people are responsible for the environment, they should act according to moral principles in respect to nature. Coexistence in a common emotional environment with nature appears to be the most important vital treasure. Behavior of those people who love nature passionately is kind, benevolent, responsible for the society and the environment. The lives of two outstanding scientists in geology, academicians Evgenii Mikhailovich Sergeev and Nikolai Pavlovich Laverov, who were the immediate teachers of the author, show the best examples of such attitude to nature and society. The paper describes in brief the lives of these two persons, their achievements in the Earth science, and their affection to nature. Both scientists were the recognized leaders in their areas, they demonstrated a broad scope of interests, high professionalism, and active social and political platform. Love to nature was the source of their civic consciousness and patriotism.