The article summarizes materials from a multi-method research of the Ivankovo Reservoir carried out in 2022−2024 to study seasonal changes of methane concentration in water and its emission from the surface. The survey included both methane flux measurement at the water − atmosphere boundary, with due consideration of its spatial variability, and measurement of methane emissions from the bottom sediments.

The measurements were carried out by a chamber method (floating and bottom). The samples were processed using the Chromatek-Crystall 5000.2 chromatograph. Sampling locations were chosen taking in account the morphological structure of the reservoir, the type of bottom sediments, and the depth intervals. The measurements have shown that the values of methane flux on longitudinal and transverse sections could differ by two orders of magnitude. Its lowest values are within the areas with sandy bottom. The highest value of methane flux is in the area with significant anthropogenic load, i. e. from the inflow of the Shoshinsky reach to the Ploski village. According to the classification based on the water exchange coefficient, the Ivankovo Reservoir belongs to the group of flow-through reservoirs with seasonal flow regulation; however under certain weather conditions the oxygen deficiency areas appear in the reservoir. During these periods, the methane flux from such areas becomes comparable with that from the low-flow water bodies. Therefore, the summer decrease in flowage and more frequent heat waves are unfavorable factors increasing the methane emission. Low-water periods when the water level decreases relative to the FSL during the navigation period are also unfavorable because of the increase in methane flux.

The obtained values of methane flux were compared with published data, and significant differences were found for the spring period. A methodology for estimating methane emission from a reservoir is proposed, taking into account the factors that determine its flux. Seasonal changes in emission are described, and the increased frequency of measurements and the need to measure methane flux over different types of macrophytes are argued.

The article analyzes the transformation of environmental components in the impact region of the JSC Karelian Pellet, Republic of Karelia. The content of metals (Mn, K, Sc, V, Sr, Fe, Cr, Co, Cu, Ni, Zn, Cd, Ba, Pb and Ti) in soils, bark of Pinus sylvestris and leaves of Betula pubescens was measured, and the changes in anatomical and morphological characteristics of indicator species were studied. The natural and territorial complexes in the Kostomuksha Nature Reserve were taken as a background. It is shown that the chemical composition of soils and plants depends on that of the underlying rocks, specific features of ore occurrence and the intensity of peat accumulation. When dusting from quarries, the soils receive K, Sr, Ba, Fe, Mn and Ti. Pollution from motor vehicles is an agent of increasing concentrations of Pb, Zn, Cu and Cd in soils and plants. Biotesting on Daphnia magna and Chlorella vulgaris have shown a low level of soil toxicity. Application of a set of bioindicating parameters revealing even minor environmental changes proved to be the most demonstrative one. Morphological deviations of plants under the influence of pollution increase by 1,5–4 times, the projective cover of epiphytic lichens decreases to zero compared with the background. The climatic signal in the radial growth of P. sylvestris is suppressed by anthropogenic impact within the plant area, the minimum and maximum growth indices decrease by 1,5–3 times relative to the background. The bioindication integral parameter (BIP) based on the Harrington’s desirability function indicates the absence of pollution in the reserve (BIP = 0,77–0,84), and “average” (BIP = 0,37–0,63) and “high” (BIP = 0,28–0,37) degree of environment transformation near production facilities within the plant territory. The outskirts of roads, production sites, and cuttings are overgrown with apochoric and ruderal species, such as Urtica dioica, Calamagrostis arundinacea, Chamaenerion angustifolium, Tussilago farfara, Picris hieracioides, etc. Invasive Ribes nigrum, Frangula alnus, Melandrium dubium, etc. occur widely within the reclaimed areas of old dumps of overburden grounds. The need for regular monitoring and control of the content of metals, especially Fe, Ni, V, Pb, Cu and Zn, in environmental components within the impact area of iron ore enterprises was noted.

The article discusses the problem of assessing the spatial organization of household waste storage. The authors analyze the territorial structure of municipal solid waste (MSW) facilities in the Republic of Tatarstan. Specific features of the functioning of existing MSW landfills are analyzed, and the dynamics of their filling is studied. Based on the method of interpreting satellite images, the rate of filling the plots of the solid municipal waste landfill in the city of Almetyevsk is demonstrated. Using the multidimensional cluster analysis, the development levels of the sphere of solid waste management in the municipal districts of the republic are compared. Based on the data on the number of landfills, the mass of removed waste, the provision of container sites, the mass of generated and unaccounted waste, the municipal districts of Tatarstan were grouped into 3 clusters with favorable, satisfactory and tense situation in the sphere of waste management. The functioning of the waste disposal system in the region was assessed. Territories with high concentration of waste in a limited space, located in the zone of influence of large cities of the republic and being the most promising from the point of view of the development of technologies for deep waste processing and biogas production, have been identified as optimally functioning. Using geographic information technologies, the authors assess the territory of the region from the point of view of possible solid waste landfills location. Based on the data on land use characteristics, soil composition and environmental requirements, a map was compiled showing the areas unacceptable and potentially suitable for the construction of MSW landfills. Settlements, agricultural lands, summer cottages, areas of industrial and military facilities, garages, forests, environmental areas, water bodies, and roads were all considered as limiting factors. Analysis of the map allowed a conclusion that there are territories suitable for locating of MSW landfills in the central and eastern parts of the republic, but there are practically no options in its western part, especially in the Kazan agglomeration zone.

The article presents the results of the study dealing with the spatiotemporal variability of ionic runoff within the Northern Dvina River basin. Based on long-term hydrological and hydrochemical data collected from the state observation network of Roshydromet between 1990 and 2017, the values of ionic runoff and the modulus of ionic runoff have been calculated, both for the sum of ions and individually for specific components, namely sulfates, chlorides, bicarbonates, and calcium ion s. Bicarbonates dominated in the structure of ionic runoff, accounting for up to 50%. The ionic runoff of the Northern Dvina River reached its highest average long-term values at the outlet section near the village of Ust-Pinega; among the tributaries, the highest absolute values of ionic runoff were characteristic of the Vaga and Sukhona rivers. Based on the analysis of the Kendall rank correlation coefficient values, statistically significant trends in the changes of ionic runoff have been identified for the rivers of the Northern Dvina River basin. It is shown that the long-term dynamics of ionic runoff is characterized by a decreasing trend only for certain sections of the Northern Dvina and Sukhona rivers; for most other river sections, temporal changes in ionic runoff are statistically insignificant. Analysis of the identified trends in the runoff of individual macrocomponents revealed that most of them are decreasing and have a moderate strength of association. Increasing trends were observed only for the runoff of bicarbonates in the Luza and Sysola rivers and for sulfates in the Sukhona River. Based on a comparison of runoff modulus, the ionic runoff load on various sections of the Northern Dvina River basin has been evaluated. It was revealed that the highest load of the main ions runoff is characteristic of the Vym River, and the lowest for the Sysola River. For most of the studied rivers, the load in terms of the ionic runoff modulus is estimated as average.

Beaded channels of small rivers, with alternating lake-like extensions and narrow channels connecting them, are widespread in the steppe zone. Nevertheless, their origin is still controversial. A version of the beaded channels formation in the steppe zone is the siltation of rivers; however the rates of sediment deposition, their composition and features of their distribution on the floodplains of beaded rivers have not been specially studied. The rates of overbank deposition were determined for the floodplain complex of the Kardail River, which has a beaded channel, using the 137Cs. The duration of inundation of different floodplain levels was estimated, and the granulometric composition of overbank deposits, suspended sediments, channel bottom sediments and soils was specified. The rate of overbank sediment deposition for the period from 1986 to 2024 grow in line with the increasing duration of floodplain inundation and amounts to no more than 1,6 mm/year for the high floodplain, 2,4–3,2 mm/year for the middle floodplain, and 10,5–13,2 mm/year for the low floodplain. The decrease in flood water rise is characteristic for all rivers in the region and leads to a decrease in the rate of sediment deposition on the middle and high floodplains. Compared with higher floodplain levels, low floodplain deposits are characterized by a higher content of plant residues and an increased proportion of silt. The finer composition of low floodplain deposits could be a result of its longer inundation, dense reeds on its surface, which slow up the flow, and the fine composition of the main sources of suspended sediments, i. e. arable soil horizon and channel bottom sediments. It was found that the rates of sediment deposition at different levels of the Kardail River floodplain correspond to those of other rivers, including those without a beaded channel morphology. The presence of the clay base under organic rich deposits within low floodplains in the narrowings of the channel indicates that the deposition of organic rich deposits is not the main cause of the formation of channel extensions, but it makes their morphology more pronounced.

The concept of a 15-minute city was first introduced in 2016, and aims to create urban environments where all basic needs of residents could be met within a 15-minute walking distance. The study focuses on the «Zilart» residential complex, constructed on the site of the former ZIL automotive plant in Moscow. The primary goal of the research is to assess the conformity of the new development with the principles of 15-minute accessibility and analyze the applicability of this concept in Russia. The article proposes an original interpretation of the novel concept in domestic urban planning practice. The research examines such characteristics of the residential complex as compactness and diversity of infrastructure facilities, as well as the impact of the concept on satisfaction of the residents. The research methodology includes comparative and cartographic analyses using Geographic Information Systems (QGIS). The comparative analysis, based on existing literature, facilitated the compilation of a list of essential infrastructure elements adapted to the case study. The cartographic analysis enabled to find out the spatial accessibility for identified infrastructure facilities. A statistical method was employed as a supporting and complementary tool, using the surveys of residents. Based on the generated maps, the infrastructure was evaluated against the criterion of residents’ satisfaction. This revealed both positive aspects, such as high transport connectivity and integration with the city, and shortcomings, such as uneven distribution of certain infrastructure types. The results of the geospatial analysis indicate that the infrastructure of the «Zilart» residential complex partially meets the criteria of the 15-minute city concept by ensuring the accessibility of all essential facilities. However, the residents’ surveys revealed that social and cultural ties to traditional urban norms of Moscow reduce the level of micromobility and neighborhood autonomy, contradicting the stated concept. The presented study not only evaluates the «Zilart» residential complex in terms of its compliance with the principles of the 15-minute city but also represents an attempt to develop methodological approaches for advancing similar projects in Russian urban planning.

The detailed isotopic plots based on δ18O and δ2 H values were analyzed for two parallel and synchronous syngenetic ice wedges (IW-17 and IW-20), exposed in the upper 20 meters of the outcrop in the Batagay Yedoma (Upper Ice Complex), Northern Yakutia. Based on the new 14C accelerator mass spectrometry (AMS) datings of organic matter extracted from the ice, the ice wedge formation began no later than 42 ka BP, slowed significantly around 26 ka BP, and ceased around 11 ka BP. Very low values of the isotopic composition were observed in the studied ice wedges. The mean δ18O values ranged from −31 to −36.2‰, while the mean δ2 H values ranged from −232 to −283‰. Comparison of the detailed isotopic curves for the two adjacent ice wedges allowed to identify sections at the same depth with similar isotopic values, as well as sections with isotope data that differed by 1−2‰ for δ18O and more than 10‰ for δ2 H. Different isotopic signal from adjacent ice wedges at the same depth may be explained by different frequencies of frost cracking during the present stage of their growth. This is associated with reaching an optimal width, at which cracking occurs more intensively. The lower δ18O and δ2 H values for IW-20 compared to IW-17 at a specific depth probably suggest that these ice wedges belong to different polygonal systems. The primary generation ice wedge (IW-17) was more likely to crack, while the secondary generation ice wedge (IW-20) located within a primary polygonal network cracked during severe winters only. It was found that between 42 and 26 ka BP, ice wedges in the Batagay Yedoma were formed under severe winter conditions of the Late Pleistocene. The mean January air temperature during the ice wedge growth period ranged from −47 to −53°C. During the initial stages of each ice wedge growth cycle, frost cracking and their growth mainly occurred during colder winters.

In the article the authors present an assessment of the current state of knowledge about the relief and its formation within the territory of Greater Moscow. Based on the analysis and generalization of literature, cartographic materials (including the remote sensing materials) and field studies, the medium-scale geomorphologic map of the territory of New Moscow was compiled using the chronomorphogenetic principle, as well as a series of large-scale geomorphologic maps for key areas, in particular, for protected nature areas of Moscow. Primarily natural relief is described, which forms the basis for the anthropogenic one. General features of the sub–relief (natural and anthropogenic), dangerous and unfavorable modern relief–forming processes for the territory of “Old” and “New” Moscow are highlighted. The shares of different morphogenetic relief complexes within the capital’s area occupied by are estimated.

The article presents the results of study of polyaromatic hydrocarbons in the Northern Caspian and the Middle Caspian marine environment. The spatial and temporal dynamics of PAHs concentration is described on the basis of the materials gathered during 2017–2021. The study was based on the results of industrial environmental monitoring of the licensed areas of mineral resources use in the northern and middle part of the Caspian Sea. The data of industrial environmental monitoring were analyzed by standard statistical methods. It should be noted that the seasonal variability of PAHs concentrations in the Northern Caspian is characterized by the spring increase in PAHs amount for almost all period under study. A common feature of PAHs dynamics in the northern part of the sea is an upward trend from 2017 to 2020 and its decrease in 2021. No seasonal patterns in the variability of PAHs were found for the Middle Caspian. There are not found stable trends in PAHs concentrations in this region. Concentration range and fraction in the sum of all PAHs were determined for each of the PAH components. As a result of the study the dynamics of water content of marker hydrocarbons, such as pyrene, benz(a)pyrene, fenantren, acetenaften, anthracene, chrysene and naphthalene, was revealed. A redistribution of the mass share of the main components of PAHs occurred in 2019. Acetenaften, fenantren and naphthalene were the most common in the Caspian Sea water. Analysis of molecular-diagnostic ratios proves the presence of anthropogenic and natural sources of polyarenes and the mixed origin of hydrocarbon pollution in the Caspian Sea. Analysis of molecular-diagnostic ratios shows the presence of anthropogenic and natural sources of polyarenes and the mixed origin of hydrocarbon pollution in the Caspian Sea. A number of patterns have been identified through correlation analysis. There is a strong feedback between the ratios (pyrene + benz(a)pyrene)/(fenantren + chrysene) and fenantren/anthracene in the Northern Caspian. And there is also a direct correlation between the ratios naphthalene/fenantren and anthracene/(anthracene + fenantren). Analysis of correlation relationships of indicator ratios in the Middle Caspian did not reveal any dependencies, which may indicate a variety of sources of contamination by polyaromatic hydrocarbons. 

The article analyzes the factors of positive dynamics of a small city population throughout the post-Soviet period using the example of the town of Izberbash. In 1989–2020, the population of Izberbash increased 2-fold – from 28 to 60 thousand people and the city moved from the category of small to medium-sized cities in terms of population numbers. The development trends of Izberbash are similar to those of small cities in North Africa, the Middle East, Central and South Asia. The main reason for the demographic growth of the city is a significant migration inflow from the neighboring predominantly rural areas of mountainous and pre-mountainous Dagestan. This resulted in a significant growth of the city’s built-up area. Along with the actively growing private sector, new residential quarters are being built in the city center, and high-rise buildings are being densified. The results of questionnaires and interviews with the local people revealed the elements of false urbanization: residents who migrated from the surrounding rural areas in the 1980–2000s, and even their children born in the city, do not have a clearly defined urban identity. The city has undergone a radical transformation of the population composition in the post-Soviet period. At the same time, there is still social tension between old urban dwellers with modernized value system and new ones who are more traditionalistic. The observed processes take place under active migration exchange between the city and the surrounding rural areas which is facilitated by a combination of mutually reinforcing groups of factors pushing the rural population out of the mountainous area and attracting it to the nearby city with more developed infrastructure. The socio-economic situation is further complicated by a significant growth of tourist flow to the city from other regions of Russia and the Republic of Dagestan in the last five years.

Record-low unemployment and high demand for logistics services, especially from e-commerce, have intensified employee shortage in transportation and logistics. It is noted that the demand for labour in the sector is growing 1,5 times faster, and the offer is 20–25% slower than in economy as a whole. Focusing on the Moscow agglomeration, the authors analyzed spatial patterns and characteristics of labour resource distribution within the transportation and logistics.

The research used data from the HeadHunter portal and the Municipalities’ Indicators Database (MID), recalculated for 10-km segments within the Moscow agglomeration. The segments were grouped into five belts by the distance from the Moscow Ring Road (MRR) and the proportion of employed in the transportation and logistics: 0–30 km (over 10%), 30–60 km (3–5%), 60–80 km (less than 2%), 80–100 km (2–3%), and 100 km or more (over 5%).

The belt closest to the MRR (0–30 km) concentrates the highest numbers of transportation and logistics employees but since 2020 it is decreasing because of the airport job reductions following the COVID-19 crisis and 2022 geopolitical events. The Central Ring Road attraction zone (30–60 km) experienced steady employment growth driven by construction of new large warehouse facilities but faced reductions by late 2023 due to migrant outflows. The 60–70 km zone (A-108 road zone) has the minimum proportion of those employed in transportation and logistics but may potentially attract excess employment from the nearest belt as warehouse construction shifts towards the agglomeration’s periphery. Peripheral belts exhibited active post-2021 growth, primarily supported by increasing employment in large warehouse facilities of online retailers. Overall, transportation and logistics remains a labour-surplus economic sector. The problem of employee shortage could be partly solved by the automation of linear operations, particularly at large warehouse facilities.

The study of the Caspian Sea level changes during the Holocene predetermines the interest to palaeogeographic reconstructions of sedimentary environments in the Volga River Delta. Diatom analysis has been for a long time used for the reconstruction of coastline positions of the seas and lakes. In our study diatom assemblages from the surface layer of bottom sediments in the lower delta water bodies with different hydrological characteristics are compared with fossil ones taken from the boreholes in the upper and lower delta. In order to identify diatom indicator species of recent habitats and improve the palaeoreconstructions of earlier sedimentary environments using the actualism method we applied the following statistical methods to samples of recent and fossil diatoms: principal component analysis (PCA) and non-metric multidimensional scaling (NMDS). Statistical analysis of diatoms from recent bottom sediments and sediments from two cores in the Volga River delta let us create a database for reliable palaeoreconstructions of the sedimentation stages in deltaic channels and low flow waters within the study area. In the upper part of both cores, which corresponds to the latest stages of sedimentation, species non-common for recent diatom habitats were identified, namely Hantzschia amphioxys and Craticula cuspidata, which are probably indicators of subaerial conditions. The environments of freshwater lakes (il’mens) having no analogues among the studied modern habitats were also identified in the boreholes’ sediments, which was confirmed by their lithological composition. Species of Epithemia and Eunotia genera are indicators of these conditions. Compared with fossil material, we observed a sharp increase in the proportion of the planktonic species Aulacoseira granulata (up to 90%) in some samples of the surface layer of bottom sediments from the Bystraya River, the Sazaniy Kultuk, and the Lotosny and Dubnoy eriks. It might be a consequence of mass sedimentation of the species valves during the period of surface sampling.