Географический факультет МГУ
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CONTENTS № 3 - 2016

  • A.I. Perel’man: life and science

Migration patterns of matter in landscapes

  • Zhidkin A.P., Gennadiev A.N., Koshovskii T.S., Chendev Yu.G. Spatio-temporal parameters of the lateral migration of solid-phase soil matter (Belgorod Region)

Spatial and temporal parameters of the lateral migration of solid-phase matter (LMSM) of soils were determined for the key sites in Belgorod Region, Russia. We studied virgin forested and arable slopes with different period of plowing. The average annual rates of migration and accumulation of soil solid phase matter decrease on young croplands (plowing period of 100 years) compared to old-arable territories (150 years); both, for south-facing catenae, as well as for north-facing ones. We assessed the characteristics of soil matter transport on virgin forested slopes related to zoogenic factor. The regional trend of the change of slope exposure effect on LMSM of soils was quantitatively characterized. The similarity of the lateral pattern of zones with different intensity of migration and accumulation of soil matter on slopes with similar exposure was revealed. The following segments of catenae distinguished by acceleration or deceleration of LMSM of soils were described: stationary, progressive-migratory, regressive-migratory, stationarymigratory, and accumulative ones.

  • Samonova O.A., Kasimov N.S., Aseeva E.N. Grain size distribution of metals in soils of a gully system (southeastern Smolensk-Moscow Upland).

The lateral distribution of Fe, Mn, Ti, Zr, Ni, Co, Cr, Zn, Pb in 1–0,25, 0,25–0,05, 0,05–0,01, 0,01–0,001 and <0,001 mm grain-size fractions of humus soil horizons was studied in a gully system located in the central Protva River basin (forest zone). The metals tend to accumulate in certain grain-size fractions: Ti – in all silt fractions; Zr – in the coarse silt fraction; Zn and Pb – in the fractions finer than 0,01 mm. Clay fraction is enriched in Mn, Co, Ni, Cr, Fe; second maximum of these metals is restricted to the coarsegrained and medium-grained sand. The particle size defines the variability of metal contents and their lateral distribution across the gully catchment area, its slopes, bottom and fan. A relatively uniform distribution of metals is found in clays, as well as in medium- and fine-grained silt, while sand fractions show a clearly uneven distribution of elements. Lateral patterns of metal distributions are dependent on different factors including the origin of soil particles (sand fraction) and the changes occurring during their migration (sand, silt, and clay fractions).

  • Semenkov I.N., Kasimov N.S., Terskaya E.V. Lateral distribution of metal forms in tundra, taiga and forest steppe catenae of the East European Plain

To evaluate the metal migration pathways, we investigated the lateral distribution of exchangeable, organic matter bounded, Fe and Mn oxide fractions of metals, as well as the total content of Fe, Mn, Co, Cr, Cu, Ni, Pb, Sr, Zn in a model loamy catenae of the southern Bol’shezemel’skaya tundra, southwestern Mezen’-Vychegda Plain, and Plavsk Plateau. Soils were shown to be depleted in Fe, Sr, and Mn, whereas other metals have close to clark concentrations. In the succession of catenae tundra-taiga-forest steppe, the total concentration of Pb decreases, as do the total concentrations of exchangeable compounds of Fe, Cu, Zn and Fe oxide fractions of metals. Contrary, the total content of Fe, Ni, Zn, Cu, Mn, organic matter bounded Pb, Ni, Co and Zn increase. The lateral distribution of metal forms becomes more even in the direction from tundra to taiga, and further to forest steppe catenae.

Geochemistry of technogenic landscapes

  • Nikiforova E.M., Kosheleva N.E., Khaibrakhmanov T.S. Ecological impact of antiglaze treatment on soils of the Eastern District of Moscow.

The environmental consequences of long-term use of de-icing salts (DS) in the Eastern Administrative District (EAD) of Moscow manifest themselves as anthropogenic salinity and alkalinity of soils. Chemical composition of reagents, levels and distribution patterns of soluble salts and exchangeable cations in snow meltwater and soils were described for different land-use zones. Mixtures of DS salts based on sodium chloride and sodium cause salinization and alkalinization of soils. These salts produce dispersion and peptization of soil colloids, which coagulate under the influence of salt electrolytes, thus increasing soil density. Alkalinization of snow cover in EAD is characterized by an average increase in pH compared to the background level by 0,6 units. The average salinity of meltwater is 19,4 mg/l, which is 2 times higher than the background values. According to the ion composition, snow waters belong to sodium chloride and calcium chloride classes due to the influence of the DS main salt compounds – NaCl and CaCl2. Inheriting the chemical composition of snow, urban soils acquired a neutral reaction (average pH 7,2), mineralization (15,2 cmol-eq/kg) and the solid residue (0,48%) which is 20–16 times higher than the background level. Ions of Cl and Na with enrichment factor about 100 prevail in the soil solution. According to the data of 2010, most urban soils had an average salinity and low degree of alkalinity. Extensive and contrasting technogenic anomalies of salts and exchangeable Na formed in the soil cover. Soils of traffic and industrial zones demonstrated the highest degree of salinity with NaCl and CaCl2 (up to 1,3–1,6% of solid residue) and alkalinity (up to 12–14,5% of the cation sum). Maps of soluble salts and exchangeable sodium content in the surface soil layer compiled for the EAD territory showed the extent of soil degradation as a result of its anthropogenic alkalinity. Degradation processes have affected more than 50% of the area. Soils near highways with a total area of 22,2% were assigned to the category of strongly and moderately degraded soils. Slightly degraded soils, which occupy 32% of the territory, remained in the center of the district. Non-degraded soils with an area of 45,8% are located in the residential area southward from the Enthusiasts’ highway, in park Kuskovo, as well as in the eastern part of the district located outside the Moscow automobile ring road.

  • Vlasov D.V., Kasimov N.S. Geochemical anomalies of metals and metalloids in landscape components of the eastern part of Moscow: parageneses of chemical elements and typology

Ecological-geochemical assessment of anomalies of different metals and metalloids in landscapes of the southern part of the Eastern District of Moscow was done through comparison of technogenic geochemical specialization of different environments (snow cover, road dust, surface horizons of urban soils, leaves of maple Acer platanoides and dandelion Taraxacum officinale). In order to estimate the contribution of landscape components to the overall geochemical anomaly of a certain area, the authors suggest producing ecological-geochemical portraits that represent sums of enrichment factors for pollutants in different components of an urban landscape. In the eastern part of Moscow, Cd, As, Pb, Mo, and Sb are the major pollutants. Atmogeochemical (Sb, Mo, Sn, Ag, W, As), pedogeochemical (Sb, Cd, Zn, Pb, Fe, As) and hybrid (Cd, Sb, Pb, Mo) parageneses were revealed in transit and depositional environments. Using a system of integrated indicators, typology of technogenic geochemical anomalies was proposed. It includes progressive, neoprogressive, bioprogressive, stable, regressive, relict and bioaccumulative anomalies. Stable anomalies of pollutants with the least prosperous environmental situation are located in the northwestern, northeastern, central and southeastern parts of the area close to major roads and industrial zones.

  • Avessalomova I.A. Biogeochemical heterogeneity of agrolandscapes (middle taiga subzone of the southern Arkhangel’sk Region as an example)

Biogeochemical heterogeneity reflects the internal diversity of landscapes. For agrocoenoses and plant associations of ecological framework, we estimated the phytomass, nutrient supply and nutrient uptake intensity. After cessation of agricultural use, phytocoenoses experienced multidirectional changes along with increasing biogeochemical heterogeneity of postagricultural catenae.

  • Kasimov N.S., Lychagin M.Yu., Chalov S.R., Shinkareva G.L., Pashkina M.P., Romanchenko A.O., Promakhova E.V. Catchment based analysis of matter flows in the Selenga–Baikal system.

A regional basinwide assessment of the formation of the water and suspended matter runoff was carried out for the Selenga River – Baikal Lake system. It is based on the results of integrated hydrological and geochemical research of more than 100 locations within Russia and Mongolia performed by the authors in 2011–2013 using the unified methodology during various hydrological periods. It is shown that the quantitative parameters of the suspended sediment transport are largely determined by the seasonal hydrology. Contribution of floods in the suspended sediment transport ranges from 52% of annual runoff for the large rivers up to 99% for the small ones. Chemical composition of 400 samples of the water and suspended sediment was analyzed by ICPMS / ICP-AES method. The obtained results demonstrate that Selenga River basin is enriched relative to the average content in the World Rivers by dissolved Sr, Li, U, Br, B, Mo, As, migrating predominantly in the ionic form, as well as by Fe, Al, Zn and Pb, migrating in the form of complexes with organic matter. Suspended sediments of the Selenga River and its tributaries are enriched with As, Cd, Mo, Pb, Zn, Mn, Co, which is due to both the geochemical specialization of the region (As) and the technogenic influence (Cd, Mo, Pb).

Analysis of particulate/dissolved modes of chemical elements in river water showed the prevalence of particulate modes of most heavy metals and metalloids (HMM) in the upper part of the basin and dissolved ones in the middle and lower parts. The share of suspended forms of migration increases dramatically during the floods, especially in the upper reaches of the rivers; in the lower part of the basin the impact of floods on the ratio of forms decreases, which is especially noticeable in the Selenga delta. During the floods geochemical fluxes of dissolved HMM increased towards the Selenga delta with increasing water runoff. Extremely high flows of suspended forms caused by heavy rainfall were determined in the upper part of the basin that rapidly decreased downstream due to sedimentation. In the lower part of the basin, the flows increased again due to the confluence of major tributaries. The largest anthropogenic changes in fluxes are typical for small rivers (Modonkul, Hangalyngol, Tuul, Uda et al.), impacted by the towns and mining facilities. Extremely high pollution by Cd and other metals was revealed for the Modonkul River that is significantly affecting the geochemical flows of HMM in the Dzhida River up to its confluence with the Selenga River.

Geochemistry of natural landscapes

  • Bogdanova M.D., Gerasimova M.I., Gorbunova I.A., Ryabova N.V., Lychagin M.Yu. Landscape-geochemical studies in the Selenga River basin

The landscape-geochemical map, scale 1:1,5M, was compiled to facilitate the integrated assessment of natural and technogenic fluxes of matter within the catchment area of the Selenga River with its main tributaries, and to forecast the possibility to be discharged into these rivers. The following major approaches to characterize the geochemical landscapes were applied: biological cycling, production of biomes, water migration classes. Contrasts in relief and moisture patterns differentiate conditions of substances and chemical elements translocation: removal from landscapes of highlands, predominance of transit in midlands, prevailing accumulation in intermontane depressions and in river valleys and deltas, where accumulation is associated with transit phenomena. Bearing this in mind, a purposeful interpretation was performed for the main landscape components (relief, rocks and sediments, climate, permafrost, vegetation, soils) revealing their contributions to geochemical migrations. The biogenic migration is represented in a traditional way (zones, biological cycling, production); for water migration the emphasis is put on its climatic restrictions (duration of active period, freezing and permafrost). Diverse manifestations of mechanical migration are implemented in migrational structures of different hierarchical levels.

  • Gennadiev A.N., Pikovskii Yu.I., Smirnova M.A., Zhidkin A.P., Kovach R.G. Hydrocarbon status of natural soils in taiga landscapes (southwestern part of the Ustyanskoe Plateau)

The work is devoted to the study of natural features of the hydrocarbon status (HCS) of middle taiga soils with different texture and under different vegetation cover, soil aeration conditions, including soils forming under spontaneous free flow of hydrocarbon-rich gases. A comparison between the composition and content of the main components of HCS of studied middle taiga soils and published data of southern taiga soils was conducted; it is concluded that the local moisture conditions play a more important role in the formation of HCS of soils than subzonal bioclimatic differences. Biogeochemical type of HCS is predominant for natural soils. In some soils, the affiliated emanation type may be detected, which differs from the biogeochemical type mostly by the gas component of HCS.

  • Asadulin En. E., Miroshnikov A.Yu. Geochemical variability of terrigenous bottom sediments in the western Kara Sea.

The main component of the Kara Sea bottom sediments is terrigenous material from the huge catchment area of the largest Siberian rivers Ob’ and Yenisei. The rivers carry this material mainly in suspended and colloidal forms; its further precipitation occurs on geochemical barriers «river-sea». The territory located westward from the Yamal Peninsula represents the part of the Kara Sea that is beyond the main direction of river flows. Here coastal abrasion of the continent and Novaya Zemlya Archipelago plays the major role in accumulation of bottom sediments. This work is devoted to the identification and grouping of diverse bottom sediments of the western Kara Sea according to their geochemical characteristics. Terrigenous material of the Ob’ or mixed Ob’-Yenisei geochemical type was found to predominate in the composition of bottom sediments. The wide areal distribution of this material likely results from the migration of the lenses of freshened water from the Ob’ and Yenisei estuaries above the saline seawater and precipitation of suspended terrigenous material on the lateral saline geochemical barrier. The areas where material of different origin is accumulated, particularly, supplied by coastal abrasion, are traced by elevated or reduced content of certain elements relative to the Ob’-Yenisei geochemical background. These territories have limited areal extent.

Jubilee

  • The 70th anniversary of N.S. Kasimov

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