Nº 3 (2024)

The paper is prepared to commemorate the 110th anniversary of birthday of academician Evgenii Mikhailovich Sergeev, and it shows his contribution to the development of one of the main branches of the modern engineering geology, i. e., regional engineering geological investigations. The brief review of the works in regional engineering geology is given that were performed by the staff of the department of soil and rock engineering and engineering geology at the Lomonosov Moscow State University under the leadership by E.M. Sergeev during 30 years (1950–1980).

At present, the hydrological characteristics of small rivers are understudied in Russia. Taking into account the increasing deterioration of the ecological state of surface watercourses, which primarily affects the intra-annual distribution of water runoff on small and medium-sized rivers, in particular, the study of runoff formation, its variability and intra-annual changes become the most important task of hydrology. The paper considers changes in the indicators of intra-annual distribution of river flow in the upper reaches of the Sviyaga River in the almost complete absence of knowledge of changes in the flow of small and medium-sized rivers in the study area. It was necessary to identify what changes the water runoff from small and medium-sized rivers undergoes in the upper reaches of the Sviyaga River, which is complicated by the occurrence of karst. The paper presents an analysis of the intra-annual distribution of water runoff, and natural factors that have the maximum effect on the intra-annual distribution of water runoff for rivers in the study area, as well as its assessment against the background of climate change. The identified types of water regime are described. Based on the research results, a typification of rivers is proposed according to the annual water flow and zoning of cross-sections by river types. The intra-annual distribution of water levels and discharges are analyzed, the factors influencing them are assessed, and the most significant of them are identified.

The issue of fire hazard in abandoned peatlands is particularly relevant nowadays, as the negative consequences of peatland fires lead to deterioration in public health and the functioning of the entire infrastructure system. The problem of predicting and assessing peat burning is a global one, with numerous studies being conducted not only in Russia but also abroad, i. e., in CIS countries, Southeast Asia, Canada, and the United States. However, the relationship between vegetation communities and the frequency of fires receives insufficient attention. The study is devoted to assessing the condition of degraded peatlands using geobotanical indicators of peat soils on the example of peatlands in Leningrad and Pskov regions. Three key objects were selected, which represent abandoned peat deposits. The methodology for assessing the fire hazard of peatlands is based on a comprehensive approach, including the creation of large-scale vegetation maps using a series of satellite images and field geobotanical descriptions, and the analysis of fires on objects for the period from 2000 to 2023 using satellite images and thermal data. As a result of the study, maps of fire frequency and duration and maps of natural-territorial complexes for each plot were obtained. The analysis of the relationship between vegetation communities and the frequency of fires showed that the species composition of the communities correlates relatively well with the time elapsed since the date of the last fire, and to a lesser extent with the duration of the fires. Indicative relationships between fire frequency and vegetation cover are quite strong, so the type of vegetation cover can be used as an indicator of fire frequency on a peatland. On territories with peat bogs with a sparse birch forest, fire occurs at least once every 5 years. On territories with sphagnum associations and reed swamp associations, fire occurs no more than once every 20 years.

In this work, we conducted an experimental evaluation and analysis of the characteristics and makeup of red-colored rocks from four representative Cretaceous and Jurassic sedimentary sequences in the western Sichuan Basin of China, as well as their weathering products. To determine the direction of weathering processes and the cause-and-effect link between the characteristics and composition of the parent rocks and the excess chemical components in the weathered soils, the chemical index of alteration was calculated. The findings demonstrated that, with regard to features like color, density of solid component, organic carbon content, granulometric composition, pH, mineral composition, and content of main chemical elements, all samples of weathered (dispersed) soils are quite comparable to the parent rocks. All samples of weathered soils and parent rocks exhibit similar chemical weathering characteristics and an index, according to the results of the CIA_corr calculation and the examination of the A–CN–K triangle diagrams. Furthermore, all of them have attained a moderate level of chemical weathering, with samples from Jurassic rocks (J₃p, J₃s, and J₂s) having far lower weathering intensities than those from Cretaceous rocks (K₁c). The red-colored rocks are characterized by weak chemical weathering and rapid development of physical weathering. This weathering characteristic can be attributed to the parent rock’s uniform texture and mostly clayey composition, which break down readily in environments with high humidity and plenty of heat. The low level of chemical weathering is due to the fact that the parent rock itself has undergone a significant change in chemical composition during sedimentation and subsequent diagenesis, and has acquired a high degree of resistance to subsequent transformation under modern conditions. Therefore, the characteristics and makeup of purple soil are mostly determined by the parent rock.

The problems of heavy metals (HM) leaching from fly ash (FA) produced by municipal solid waste incineration during its burial or use are considered. The composition, chemical properties and mineralogy of FA are described, experiments on leaching from FA in waste incinerators and in buried FA are considered, the risk from HM release is assessed, and the results of calculation and modeling of HM leaching coefficients are presented.

The issues of solid municipal waste (MSW) management are very urgent now due to the increasing accumulation of MSW amount along with rapidly rising urban population. Despite all the efforts undertaken for developing a high-tech infrastructure for waste treatment and disposal, a significant part of it is still disposed to landfills. The index of favorability for the MSW landfill allocation is determined on the basis of a comprehensive account of geoecological constraints and socioeconomic conditions; it reflects the regional differentiation between the administrative subjects of the Russian Federation. The suggested approach to assessing the subjects’ territory for the scientifically grounded placement of MSW landfills contributes to solving the problem of effective waste management.