Settlement is considered as a geographical entity, consisting of a combination of permanent and variable components. The former are population groups, infrastructure, enterprises and organization of social services, while the latter include enterprises that provide the participation of a settlement in the territorial division of labour and its specialization, as well as the natural resource and natural components of an enclosing geosystem. Forward and reverse, direct and indirect links between social and economic components, as well as between them and natural resource and natural components, are identified. The conclusion is that the node of the closest inter-component links is integrated in the geographical space of a settlement. A structural and functional model of a settlement is proposed, which includes series of permanent and variable components. The combination of various series was evaluated in terms of the share of employed for a group of urban settlements in the Primorsky Krai.
It is revealed that the share of permanent components varies slightly in different cities with no relation to their population numbers, while the share of variables differs greatly.
The structuring of territory outside the settlements is considered, i. e. between two settlements interconnected by a transport link. The territory partly gravitates towards one settlement and partly to another one. Ultimately, a territorial socio-economic system with structural links of the first order and a detailed structuring of the central settlement is considered to be an object of integrated geographical research.

In many countries approaches to the assessment of the potential of development in rural areas have been changed, which was reflected in the state policy. This research field is extremely important for Russia, primarily because of the geographical contrasts of its vast territory. In 2019 the state program of integrated development of rural areas was first adopted in the country. An important tool to reveal disparities in rural development is the typology of rural areas. The paper focuses on the issues of typological studies of rural areas with regards to Russian specifics and presents the results of their typology at different scales. Different impact of the factors of spatial differentiation of rural development was described for two levels, i. e. between the subjects of the Russian Federation and municipalities of the Bryansk oblast. Different variables were analyzed at the macro level. Some of them characterize features of the "rurality" of regions. Spatial distribution of the types, determined with the cluster method, clearly demonstrates longitudinal and latitudinal zonation. The southern agrarian and the northern non-Chernozem regions belong to different types. High percentage of aged population is a specific demographic feature in most regions of European Russia. Other regions are specific in their involvement in migration flows and ethnic composition. Rural areas of the central European part are better provided with transport, social and communal infrastructure. However, rural areas equipped with running water, sanitation, and central heating systems account for just one-third of the territory even in the most successful regions. The availability of infrastructure is extremely poor on the periphery, and, especially, in the North. The natural increase of population and the migration balance were used as indicators for typology of rural areas of the Bryansk oblast on micro level. Four types of municipalities were identified, i. e. depressive periphery, sustainable developing and stable peri-urban, and agrarian leaders.

The article draws attention to the regionary effect which is pronounced on the territories of Russia. During the 1990s–2000s there was a pause in the studies on the regionary effect after significant works of Soviet economic geographers, because the main attention was paid to the agglomeration effect. Meanwhile, the industrial region and associated economic effects continue to exist, but are primarily considered by large corporate structures. According to the authors’ estimates, the regionary effect could cost billions of roubles, not received by the state and society. The modern industrial region of Russia, in which the main regionary effects are formed, differs from both the classical economic region of N.N. Kolosovsky, and its foreign analogues, i. e. the Marshall-Becattini’s industrial areas. It has lost its complex nature and acquired microspecialization, directed not only to the national, but often to the global market. It is now consolidated by both "land" transport infrastructure, air, information and communication networks and technological proximity, based on temporary geographic proximity. The diameter of such a region varies from 300 to 600+ km, depending on the degree of concentration of a particular industry. The task is to ensure a smart economic mergence of various parts of Russian space into unified industrial areas providing economic effects in the interests of the state and society. Measures of active state policy should, on the one hand, create infrastructural and other prerequisites for the complete realization of the regionary effect within the territories of Russia; and, on the other hand, to withdraw a part of the profit of corporations created on the basis of the regionary effect in the interests of the balanced development of the country and its regions. Synergy of the joint use of the agglomeration effect in urban spaces of the main settlement zone where the leading centers of Russian engineering are located, and the regionary effect received by resource corporations in the northern and Arctic regions could be particularly constructive if the government encourages the interfirm contracting of enterprises of the north and the center.

The article discusses the main trends in the nature of atmospheric pollution by large thermal power plants. The stages of formation of the modern Russian energy system are identified. The power plants were built farther from the cities gradually shifting from large cities to medium and small cities and urbantype settlements. Regional electric power plants as a basic element of the country’s energy system are much more dependent on the economic situation than CHP plants. The amount of energy produced and the fuel consumption of regional electric power plants decreases faster in crisis years. The dynamics and structure of regional electric power plants emissions depend on three main factors, i. e. capacity utilization; fuel balance structure; and modernization and creation of new treatment facilities. The share of gas-burning plants in total emissions of regional power plants is three times less than their share in the total capacity. On the other hand, coal-based electricity generation accounts for 78% of emissions that is 2.7 times more than their share in the total capacity. The modern period is characterized mostly by modernization of the first-generation power plants rather than construction of new ones. Thus the emissions are reduced, their structure is transformed and the area of pollution becomes smaller. Case study of the impact of the Kashira regional power plant on the air quality shows that atmospheric emissions reduced significantly due to modernization. The main air pollutants near the Kashira regional power plant are particulate matters and sulphur dioxide, while carbon oxide is the least contributor to air pollution.

The article discusses possible processing of data from a mathematical model, which allows identification of areas where cascading is observed. Cascading is a bottom gravity current along and across the bottom topography slopes, that transports denser water formed in the coastal and shelf areas of seas and oceans. The NEMO model calculation for the period 1986–2010 is used as an initial data set for the Severnaya Zemlya Archipelago area with the time resolution of 5 days and the spatial resolution of 1/10°. The choice of the area is due to the availability of hydrological data indicating the occurrence of cascading during 1984 and 1985 expeditions.
The suggested algorithm makes it possible to identify the areas of cascading occurrence, namely three cases in December 1991 and 1993, and December 2004 – January 2005 near the Maly Taimyr Island. The case of cascading in December 1991 was analyzed. The comparison of water densities at the bottom and overlying horizons for the neighboring grid nodes during four consecutive 5-day periods (December 12–31) revealed the transition of stable density stratification of waters to the stratification characteristic of cascading. During the third 5-day period dense waters formed in the nodes with shallow depth (16 m) flow down the slope to a depth of 66 m. The density of water increases as a result of salinization during ice formation in shallow waters near the Maly Taimyr Island. Thus, the depth difference of cascading was 50 m. During the fourth 5-day period after cascading, the density structure becomes stable again. It was found that the 5-day time interval of the model data array applied for the study is sufficient to reveal the cascading process.

Various numerical characteristics of topological and metric properties are often used to study the transport networks. The most popular of them is the betweenness centrality. It is used to describe the hierarchical structure of network elements (arcs and vertices). It equals the number of shortest paths that pass through particular element of the network. Thus, it shows the importance of the element for the whole network.
The betweenness centrality parameter was used by various authors as both an analysis tool and an independent object of study. In particular, many experts were interested in how this indicator reflects the real functioning of a transport network, for example, the utilized capacity of its elements. Correlation and regression analysis of the utilized capacity and betweenness centrality for a number of real networks has shown that there is a direct correlation between these values. However, it is not strong enough to be used to predict the utilized capacity of network elements on the basis of their betweenness centrality.
The paper presents the in-depth study of the relationship between the betweenness centrality and the utilized capacity as a part of more general relationship between the morphological and functional properties of transport network. The utilized capacity of network arcs was modeled for the motorway network of the Sverdlovsk Oblast using the gravity model of origin-destination matrix. Different parameters of the gravity model resulted in different loading modes; each of them was analyzed in terms of their relationship with the betweenness centrality.
As a result of modeling and analysis, it was found that the correlation ratio between the betweenness centrality and the utilized capacity depends much on the transport behavior of network users, namely the distance of their trips. If the average trips length is significantly longer than the average arc length, there is a strong correlation between the betweenness centrality and congestion. Otherwise, there is no significant relationship between the betweenness centrality and the utilized capacity of the network.

The current regime of turbulent heat exchange with the atmosphere over the Barents and Kara Seas was investigated, and its spatial, seasonal and temporal variability during 1979–2018 was estimated by the root-mean-square deviation values. It is shown that in recent decades the localization of the centers of maximum energy exchange between the sea surface and the atmosphere was practically the same as in the middle and second half of the 20^th century. The highest seasonal and synoptic variability of heat fluxes is typical for the central and western parts of the Barents Sea. In the cold season both indicators of variability are 2–5 and more times higher than in the warm season, and the spatial heterogeneity of variability indicators in winter is about twice that in summer. Quantitative estimates have shown that winter spatial variability of fluxes within the Barents Sea may exceed summer values 5 to 10 times or more. The most pronounced heterogeneity of fluxes field over the Kara Sea is typical for autumn and early winter seasons.
Calculated annual amounts of sensible and latent heat fluxes from the surface of the Barents Sea exceed the values for the Kara Sea by an average of 3–4 and 5–6 times, respectively; and in some years they may differ by tens of times. For the period under study no single trend of the annual magnitude of integral sensible and latent heat fluxes over the water area was recorded, although there are multi-years decadal fluctuations. It is shown that, despite the significant difference in thermal regime of the Barents and Kara seas and lower atmosphere above them, the inter-annual changes in the total turbulent flows are quite well synchronized. This indicates the common character of large-scale hydrometeorological processes, influencing the energy exchange between the seas and the atmosphere.

Changes in climatic conditions significantly adjust the regime of surface runoff. In particular, current trends in climatic indicators over the zone of runoff formation within the Kazakhstan part of the Ili River basin, located in the mountain systems, change the flow characteristics of rivers. Analysis of the dynamics of average air temperatures and annual precipitation totals using the data of meteorological stations at different heights above sea level, generally allows identifying patterns and trends in surface runoff within the drainage-forming catchment areas. The paper presents conclusions about significant changes in meteorological indicators and identified periods of relatively stable state of their average long-term values, i.e. norms. The considered space-time fluctuations of the average annual air temperatures and the amount of annual precipitation made it possible to reveal that since the 1970s the average annual air temperature in the region has increased by an average of 0,74°C. And the rate of annual precipitation has increased since the early 1990s by an average of 34 mm over most of the basin. The annual runoff is unclearly related to the amount of precipitation in arid zones; however, it depends on the temporal and spatial distribution of moisturizing and results from the influence of heat balance and water balance factors. Parameters of the annual river flow for Ili, Sharyn and Shelek rivers are calculated for the identified climatic periods and with due account of the cyclic water regime of rivers in the region. The choice of calculation periods is confirmed by the analysis of homogeneity of the series of average annual water flow rates under consideration. It was found that since the beginning of the 1990s there was a fairly significant increase in annual precipitation in the region, which caused an intensive increase of the average annual water discharge of the rivers in question. So, the rate of the annual runoff of the Ili River increased by 40 m³/s (9%), and its values for the Sharyn and Shelek rivers increased by 21 and 18%, respectively. Possible consequences and prospects of solving water problems and water security issues within the Ili River basin are indicated.

The approaches to the study of the grain size of suspended sediments are analyzed. The congruency of mechanical, hydromechanical and migratory classifications is considered, and thereupon river sediments are defined as insoluble substances with grain size larger than 0,001 mm, which are the products of destruction of rocks, soils or organic compounds transformed by flocculation and sorption processes. At the same time, the "methodological" definition relevant to the filters parameters considers river deposits to be particles larger than 0,45 mm moving in the water column. Following on the database of processed sediment samples (736 samples for 36 rivers) the features of suspended river sediments of various natural territories are described. The average particle diameter of suspended sediments is 0,083 mm; fractions less than 0,001 mm account for 4%; 0,001–0,01 mm for 37% and 0,01–0,1 mm for 44%. Two-modal (49% of cases) and single-modal (46%) grain-size compositions of suspended sediments prevail in the rivers of different natural conditions. Lowland rivers have mainly two-modal and in some cases three-modal fraction distributions, due to the presence of a third maximum of large fractions (>0,75 mm). Approximately identical turbidity peaks (0,005–0,01 and 0,05–0,1 mm) are characteristic of mountain glacial rivers, while in semi-mountain and plain rivers the turbidity peaks shift towards smaller fractions (0,001–0,005 and 0,01–0,03 mm). The peak of 0,01–0,03 mm (up to 35–50% of the total sediment amount) reaches its maximum in semi-mountain rivers; it decreases as the discharge increases and the channel type changes downstream. The greatest degree of discrimination of fractions is typical for lowland and semi-mountain rivers relative to mountain glacial rivers. The rivers of lakhar valleys, as well as the Terek, Kolyma and Lena rivers, are specific groups in terms of the distribution of fractions of suspended sediments.

The paper continues research of balance between urbanization, sub- and de-urbanization in Russia, with two latter processes in a specific form of recurrent and seasonal suburban mobility of urban population. Possibilities and specific aspects of the mass drain of urban population to suburban residences in 2020 are considered in connection with the pandemic and introduced restrictions. Financial, socio-institutional and residential potential of transition from seasonal suburban mobility to actual sub- and de-urbanization are analyzed for the areas at different distances from Moscow, in particular the nearest and outer municipalities of the Moscow Oblast, northern and southern areas of the Yaroslavl Oblast, and the most distanced from Moscow municipality in the Kostroma Oblast. Despite a large number and variety of summer cottages, possible start of sub- and de-urbanization even during the crisis period depends on distance and local amenities. As for the Moscow Oblast, a longer 2020 stay in the countryside including the cold season shows that the urban population is psychologically ready to move outside the cities, and the stress suburbanization partly becomes a permanent one. The drivers for de-urbanization are insufficient within the mid- and long-distance locations (except for individual enthusiastic cases). Lack of interest in new residents from the local authorities, low quality of roads, general absence of piped gas and water supply in the center of Russia, decline of the social environment caused by the merger of smaller municipalities, all of this make flows of the Muscovites to rural territories and small towns rather irregular and unsteady.

The paper describes a complicated relationship between the relief and the oil and gas occurrence within the Volga-Ural anteclise. Our geomorphologic studies have shown that the eastern part of the structure, with a large number of oil and gas fields, is marked by increased values of the following morphometric parameters: 1) the difference between the base surfaces of the first and second orders, constructed according to V.P. Filosofov’s method at the scale of 1:2 500 000; 2) the length of watercourses of the second order; 3) the density of watercourses of the first order; 4) the depth of the vertical dissection; 5) the steepness of slopes; 6) the maximum curvature of the relief surface; 7) the density of the elongation lines constructed in the A.A. Zlatopolsky’s LESSA program. It was found that the median values of these parameters within oil and gas fields exceed the corresponding values calculated for the entire territory of the Volga-Ural anteclise, and the confidence intervals of the medians do not overlap. Using the automated analysis of the digital terrain model, a general pattern of orientations of linearly elongated oil and gas fields and slopes is revealed. The predominance of two main directions – north-west and north-east could be explained by the activation of the diagonal system of planetary fracturing. In our opinion, the relationship between the relief and oil and gas fields is due to the features of the recent tectonic movements influencing the shape of relief and the migration of hydrocarbons. The significance of neotectonic movements as factors of relief formation is evidenced by the fact that the epicenters of modern earthquakes are confined to the areas of increased horizontal and vertical dissection of relief. The relative amplitudes of compressive stresses were calculated using computer geodynamic modeling in the Roxar’s RMS 2013 program. There is a numerical correlation between their values and the coefficient of total erosion dissection of the relief with the Spearman’s rank correlation coefficient being 0,48. It is achieved if the latitudinal horizontal compression is set as an external load. Probably, this type of stress state manifests itself in recent times and is associated with the influence of the Urals mountain structure.

The investigation of the Eastern Mongolia steppes of three-feather formation (Stipa grandis, S. krylovii, S. sibirica) was carried out in 2008–2019 on 11 test plots of 100 m² each, located along a transect within the intermountain plain south of the Kerulen River valley. The structural organization of steppe communities is considered as a criterion for the sustainability of ecosystems under changing climatic conditions. It is determined by the ratio of life forms, i. e. biomorphological types of plants, identified by the adaptations to vegetative growth (vegetative mobile; growing vegetative weakly mobile; vegetative immobile and nongrowing), and the biomorphological groups (turf, root, rhizome, root proliferous, annual-biennial), as well as the composition of dominants and the species richness of communities. Deviance of bioclimatic indicators from the long-term average values (1962–1990) was determined for the period of observation. Combinations of the life forms of plants and changes in the structural organization of communities were revealed. The structure of communities was statistically verified between different years (ANOVA, Kruskal-Wallis test).
According to the change in moisture conditions (May-July precipitation, i.e. months with the maximum accumulation of phytomass) and the deviation from the long-term average values (100%), the observation years were classified into three groups: arid (<100 mm, <70%); medium (100–190 mm, 70– 130%); and wet (>190 mm, >130%). Years with increased moisture are characterized by maximum values of summer and May-summer ombrothermic index; while in the years with poor moisture and relatively low thermic conditions the values are minimal.
In the years with medium moisture conditions, the species richness was particularly high and the species of all biomorphological types were present. This is the most favorable situation for the development of steppe communities. The species diversity of growing vegetative weakly mobile species decreases in the years with dry conditions, while that of vegetative immobile and non-growing species decreases in the years with wet conditions. The years with different moisture conditions also significantly differ in the projective cover of autochthonous assectors (Cleistogenes squarrosa, Agropyron cristatum, Potentilla acaulis) and digressive edifiers (Artemisia frigida). However, the floristic-coenotic core of communities, which ensures their stability, is preserved throughout the entire period of research; it includes 25 perennial species with high constancy in communities.
The structural organization of three-feather formation steppes is reflected in species diversity and phytocoenotic role of particular biomorphological groups of species, and determines the natural potential of steppe ecosystems.

The concept of polystructurality of the landscape space is discussed. The object of research is the Matua Island with an active volcano, absence of surface run-off and widespread development of debrisflow and avalanche complexes. Landscape map of the island’s territory is presented, based on structural and genetic principles. Three geographic localities are identified within the island’s landscape, namely that of the modern Peak Sarychev volcano with predominance of volcanic deserts, that of the ancient Matua volcano (the most complex one) and that of marine terraces of different levels (from 2–3 to 60–70 m). A model of the nuclear system with a core within the volcano crater has been developed. According to the degree of volcano’s influence on natural complexes three zones have been identified, i.e. strong, medium and moderate. The main components of volcano’s impact are lava and pyroclastic flows, pyroclastic waves, tephra fallout, and gas emissions. Debris-flow and avalanche geosystems have been identified and analyzed within the paradynamic geosystems interlinked by homodromous flows of matter and energy. The material flows generated by the volcano, avalanches and debris flows were quantified. The volume of two lava flows formed during the 2009 eruption was about 10 million m³. The volume of pyroclastic deposits is estimated at 200 million m³. Calculations of debris flows of 1% probability for 15 particular debris flow catchments revealed that they can vary from 5,7 to 691 m³/s and from the first thousands to 425 thousand m3 in volume. The total volume of debris flows of 1% probability is 1,62 million m³. The total volume of 2% probability snow avalanches for 33 catchments is estimated at 21,2 million m³. It was found that in the modern period the volcano is the main system-forming factor for the majority of natural complexes of the island. It is concluded that the polystructural nature of the landscape space is clearly manifested within the island and comes from the formation of different types of geosystems, based on different physical principles, within one and the same territory.