Home – Home – Jornals – Advanced Search

Ecological consequences of a large landslide on the shores of the Bureya reservoir For the first time in the winter period (December 2018), a landslide occurred on the Bureya reservoir, the largest in Russia in the last decade. This phenomenon is not typical for Khabarovsk krai. Results from investigating toxic organic matter in the water and aufeis in the zone of influence of the landslide and after the collapse of the dam composed of rocks are discussed. A comparative analysis of aromatic compounds by gas chromatography in the water around the landslide body before and after explosions in the resulting artificial canal has been carried out. Among dominant components in the water, a number of toxic substances were detected, including methanol and methylated benzene derivatives, the concentration of which increased after drainage of water through the landslide body. It was found that a large number of volatile organic substances had a natural origin and could be contained in the pore space of rocks. After explosive blasting, an increase in the content of hexane and isopropyl benzene was observed in the water of the artificial canal. It has been established that the composition of volatile organic substances has been influenced to a greater extent by rock grinding both immediately after the landslide and after the explosive blasting. Ecological risks for the reservoir ecosystem are associated with the formation of aromatic compounds as a result of various biogeochemical processes occurring in the pore space during watering of rocks, during their thawing/freezing, the transformation of vegetal debris and detonation products of explosives.

Based on analyzing bathymetric material obtained in different years by using high-precision geophysical equipment featuring multi-beam echo sounders, the main bottom relief features of the South, Middle and North basins of the Baikal depression are considered. It has been established that ridge-ravine forms and canyon valleys are well developed on the underwater slope of all depressions. The valleys of the canyons of the Middle and South basins reach the maximum maturity, which is associated with a longer history of the evolution of these basins. The canyon valleys are highly sinuous there, which is associated with the peculiarities of the underlying substrate and fault tectonics. The canyons of the western side of the Baikal depression are predominantly tectogenic in origin, are short in length and show a significant steepness of the longitudinal profile; their valleys are mostly rectilinear. The underwater slope along the eastern coast of the North basin and its abyssal surface are complicated by a set of glacial landforms: moraine swells and fan cones formed by turbidite flows during interglacial periods. On the coast, they are continued by very extended swells of lateral and stadial moraines. Tectogenic scarps are widespread in the lower parts of the underwater slopes and run usually parallel to the coastline. It has been established that a very characteristic form of the sloping relief of the South basin are the flat-convex surfaces of the deltas which sometimes reach the abyssal surface of the lake. Numerous outcrops of Miocene-Pliocene limnic sediments on the eastern coast of the Middle basin, and the nature of their spatial arrangement suggests that the sedimentary strata of the underwater slope of this basin may be of the same age and genetically homogeneous with terrestrial strata, which are Miocene-Pliocene in age. Similar deposits of the Tankhoi field on the southern coast of the depression also extend far into the water area of the lake, which gives grounds to confirm the existing points of view about the similar history of the development of the South and Middle basins.

We made a map of the contemporary landscape structure on the key site (Goloustnoe coast) to analyze the recreational development of the coast of Lake Baikal; based on this map, we identified the main factors of natural attractiveness for the development of the tourism industry. Considering the economic and geographical patterns of the region combined with its landscape and recreational potential, we determined historically formed and preferred types of recreation activities. With a view to reveal environmental problems, we identified the main directions for recreational activities that have the greatest negative impact on the functioning of landscape complexes in the area. It is pointed out that a low level of ecological culture of vacationers is often the chief cause for an intensification of adverse events. Therefore, the risk of crisis situations is borne not only by tourists, but also by the operation of recreational infrastructure facilities. Geoimages obtained by processing images taken with an unmanned aerial vehicle helped to identify the foci of greatest environmental tension, as well as present quantitative parameters characterizing the extent of the negative impact. Having considered the high degree of sensitivity of landscape complexes to anthropogenic impact, we proposed ecotourism-oriented leisure activities that can not only reduce the burden on the part of recreational activities, but also increase the level of environmental morality. Besides, we provided the examples of recreational facilities, already existing on the Goloustnoe coast of Lake Baikal and methods of their management, guaranteeing environmental stability, which is necessary in the implementation of measures aimed at sustainable development of the Baikal territory.

The differentiation of the elements according to the phase composition of natural waters, which reliably characterizes the geoecological situation in the region of the Unzha river basin (the left tributary of the Volga river), the basicity of soil-geochemical processes and associated flows of matter and energy in soils and landscapes, was studied. Studies were carried out in key areas of landscapes in the middle and lower reaches of the river valley (35 soil sections were established). It is found that the natural waters of the Unzha basin constitute a complex multicomponent system where the ion composition of the waters and the reaction of the medium vary over a broad range according to their lithogenic component and water category. Migration of Fe, Mn, Zn and Cu in soil-ground waters of the Unzha basin proceeds mainly in suspended material, and in the dissolved phase in the waters of brooks, rivers and wells. In the waters of brooks and rivers, the total amount of suspended material is smaller than in soil-ground water; therefore, its role in the transfer of Fe, Mn, Zn and Cu is reduced accordingly. Migration of these elements increases in the composition of soluble humic acids, mainly fulvic acids. The role of dissolved humic acids, largely fulvic acids, in the transfer of Fe, Mn, Zn and Cu averages 28 %, 10, 41.9 and 33.7 %, respectively. Along with fulvic acids, the role of humic acids in the removal of these elements increases in bogs rich in organic matter. In the waters of the Unzha river, its tributaries and brooks, the coefficient of water migration К_хFe = 0.4, which is an order of magnitude higher than the corresponding value according to Perelman’s classification. In the soil-ground water, Fe migration increases further: К_хFe = 0.5. According to the intensity of water migration in the landscapes of the Unzha river, the elements are arranged in the following decreasing sequence: Zn ≥ Cu ≥ Mn ≥ Fe. A marked increase in the mobility of elements occurs in the acidic environment of the bog waters (pH 3.7-4.1), rich in dissolved organic matter.

Based on water sediment concentration modeling using the collection of Landsat images for the period 1992-2018, highly detailed (30-m resolution) features of suspended sediment load along the 200-km braided channel reach of the Lena river from Pokrovsk to the mouth of the Aldan river (upstream of the Aldan braiding) are described. It is shown that large anabranching river reaches correspond to changes of the system of sediment transport and accumulation manifesting themselves as a predominance of occurrences of positive (increase) or negative (decrease) DS₀ values (where DS₀ stands for suspended sediment concentration budget). The conditions of longitudinal decrease in suspended sediment concentration along the length of the braided reach of the Lena river are characterized by high water discharges (>20 000 m³/s) and are associated with sediment accumulation at riffles and floodplain areas. It is established that a significant role in the longitudinal decrease in water sediment concentration is played by lateral floodplain branches which accumulate a part of the incoming suspended sediments and have a dilution influence on the sediment flow downstream of the confluence with the main channel. Cases of a longitudinal increase in water suspended sediment concentration are typical for the lower water flow rates (<20 000 m³/s) and are connected increased bank erosion due to thermal erosion in summer as well as erosion of riffles during a low-water period. A combination of the grid of suspended sediment concentration, velocities and channel depths with a 30 30-m resolution (more than 20 000 cells) for low-water conditions revealed a dependence of local suspended sediment concentration on the transporting capacity of the flow which was determined for separate verticals. A correspondence between the regime of certain reaches in different phases of water regime is observed. Such a correspondence indicates the mutual influence of the directedness of mass exchange and channel morphology. The transformation of distribution systems of suspended sediments can be interpreted as one of the self-regulation mechanisms in the channel system. Complex systems of sediment flow distribution along the channel of a large river reflect the opposite directedness of erosion-accumulation processes caused by bends in the longitudinal profile.

This article summarizes material of geobotanical and biogeochemical studies into the vegetation of the Irkut river valley in the spurs of the Kitoi Goletzes of the Eastern Sayan Mountains. An analysis is made of the features in spatial structure, floristic and phytocenotic diversity of vegetation of cryo-steppe open woodland, taiga larch forests and meadow-bog complexes in the high-mountain valley of the Irkut river. It is found that the landscapes of the subalpine cold forest-steppe represented by a combination of sparse herbaceous (ptylagrostis-kobresia, fescue) larch forests, shrub groups with the involvement of Spiraea alpina, Betula rotundifolia, and Dasiphora fruticosa, and communities of cryophytic steppes typically occur at altitudes of 2000 m above the sea level. They latter constitute the original element of forest-steppe, which are often dominated by the endemic fescue Festuca komaroviis. The dominant taiga vegetation is dominated by larch forests. Larch forests are dominant in the composition of prevailing taiga vegetation. These are mainly lingonberry-rhododendron-lichen larch forests and larch forests with lingonberry moss-lichen communities. The communities of subalpine larch forests of the Il’chir urochishche showed the presence of anomalies in gold content in samples of fruticose lichens, reindeer lichen, revealed. Gold content in lichen samples varies from 0.1 to 0.8, and in some places it reaches 1-3 g/t. In general, in the Sayan alpine landscapes, gold-sulfide vein zones are known to occur in rocks of the Paleozoic volcanogenic-terrigenous formation and at its contact with the carbonate formation. Along the slope, gentle watershed ridges overgrown with taiga larch forests are interspersed with narrow hollows of cryogenic subsidence with the occurrence of boggy willow forests, sedge-cobresia, and ptyagrostis meadows with Dasiphora fruticosa. Only at the foothills, on bedrock terraces with outcrops of rocks of the Paleozoic carbonate formation, communities of cobresia-fescue alpine steppe are formed.

The composition, distribution, and genesis of organic components in bottom sediments of the Tumnin river were studied for a comprehensive assessment of their current environmental status. A study of particle size distribution revealed the dominance of the pelitic fraction in the sediments of most of the sites (up to 98.8 %). It was found that the spatial variability in the accumulation organic substances in bottom sediments led to a significant scatter in the minimum and maximum concentrations of organic carbon, by a factor of 65, and in the mass fraction of hydrocarbons, by a factor of 136. According to hydrocarbon content (from 9 to 680 mg/kg), the sediments are estimated in the range of “slightly polluted” - “very dirty”. According to the content of sedimentary pigments (from 16.1 to 39.8 mg/kg), most of the sediments are of the eutrophic type. Correlations between the main sources of organic matter in the sediments under investigation were revealed: hydrocarbons and organic carbon (r = 0.674), the content of pigments and hydrocarbons (r = 0.869), and the content of phytopigments and heterotrophic bacteria (r = 0.888). It is concluded that the value of overload of the self-purification capacity of the bottom sediments from hydrocarbons is closely associated with the presence of phytopigments (r = 0.873) and the number of heterotrophic bacteria (r = 0.959), which is due to their production and destruction activity in relation to hydrocarbons. High concentrations of volatile organic compounds (butanol, methanol, acetaldehyde, acetone, etc.) indicate that bottom sediments contribute to secondary pollution of the river water. The study of the molecular composition of hydrocarbons revealed the dominance of biogenic compounds of terrigenous genesis (53.2-76.7 % of the sum), which is important in differentiating anthropogenic impacts for purposes of environmental monitoring.

The article discusses recent changes in the development of industrial production in Irkutsk oblast from 2010 to 2019. Industry is the basic component in the economic complex; it provides about half of the region‘s gross added value and is characterized by a multi-sectoral structure formed primarily on the basis of using natural resources and cheap electricity. It is pointed out that in the last decade, a significant change in the structure of industry has led to a structural simplification of its sectoral composition with a significant shift toward the raw materials sector. Cities remain the leading centers of concentration of the manufacturing industry. The grouping of municipalities according to the level of industrial development was carried out according to the available statistical data: the calculated share of the employed in industry and the volume of shipped products of large and medium-sized organizations. On the basis of their ratio, groups of regions with intensive development of the extractive industries, primarily the oil and gas sector, as well as territories, the industrial profile of which was formed in Soviet times but underwent transformations under the influence of changes in the market, were identified. A group of regions with very low industrial development has been identified, in which economic activities are mainly related to agriculture, logging, transport, and tourism. It is shown that some of the municipalities have changed their position in the groups when compared to 2010. The rest of the composition is relatively stable. It was found that in the first and fourth groups there occurred a change in priority in the development of types of economic activity, whereas the second and third groups show a change in their proportions. Large business contributes to the extreme uneven distribution of investments across the oblast in the implementation of investment projects.

An attempt is made to empirically enrich the theoretical ideas of the economic-geographical location of cities by means of an individual economic-geographic analysis. It is shown that the most important component of monitoring the economic-geographical location implies analyzing the ecological-geographical location of a city, and for the city of Irkutsk it is of special interest. This analysis was carried out in the context of the economic-geographical location and in a multi-scale manner, because both look different at different scales. The following scales were studied: the Global scale, the All-Russian scale, the scales of the Angara-Yenisei and Baikal regions as well as the south of Irkutsk oblast. The two variants of regionalization of Eastern Siberia are not opposed to each other but are considered as equal, allocated for different purposes and forming the geographical location of Irkutsk in different ways. As for the south of the Oblast, its allocation as a special geographical system and an independent object of research is justified. An integral part of the research done involves examination of the recreational-geographical location in terms of the traditions of the citizens’ recreation: both weekend recreation and multi-day tourism, which gives rise to considering different scales and slightly different ideas of the geographic location. The analysis includes a historical context: it shows how in the relatively recent past Irkutsk became a place of non-standard political activity, which is associated with public awareness of its ecological-geographical location, formed on the basis of the obvious recreational-geographical location. The article presents the results of a sociological survey among young people, showing that the rudiments of such awareness are still present, but it is largely weakened compared to the 1980s.

The formation features in the ethnic structure and settlements of Barguzin Cisbaikalia across the territory of the modern Barguzinskii and Kurumkanskii districts of the Republic of Buryatia are considered. On the basis of archival sources and field research material, the impact of socio-administrative transformations, methods of economic activity and the specifics of the natural environment on the placement of the newcomer and old-time population are revealed. The adaptive features of local communities are shown, which led to sustainability of the traditions of nature management and everyday interethnic contacts. The nature of the settlement of the territory and the formation of a network of settlements in different historical periods had its own specifics and, at the same time, was largely determined by the degree of the preservation of the complex of nature management traditional for the ethnos: agricultural-commercial, animal husbandry-commercial, hunting-commercial and fisheries, with a number of transitional options which formed in the course of constant interaction of ethnic groups in the region. It was found that stability and continuity in the organization of human habitat are characteristic for the study area and the peoples inhabiting it. The distribution of settlements, temporary and permanent camps in different historical periods reflected the state of the ethnocultural landscape, determined the location of its functional zones and areas as well as contributing to the formation of the identity of the local population.