Dyakonov K.N. Teaching process and the lines of scientific research of the Department of Physical Geography and Landscape Science (to the 80th anniversary of the Department)
Global and regional changes of the natural environment
- Frolova N.L., Nesterenko D.P., Shenberg N.V. Intra-annual flow regime of rivers in Russia
Interrelations between parameters characterizing the intra-annual irregularity of flow (coefficient of natural flow regulation, spring flood volume as percentage of the annual runoff, etc.) and hydrographic, morphometric, climatic and landscape factors are described. Regionalization of the territory of Russia according to the intra-annual flow regime has been carried out using the data of more than 900 hydrometric gauges. Temporal variability of the coefficient of natural flow regulation has been analyzed for several rivers. It was found out that since 1935 permanently decreasing variability of runoff is typical for the rivers of the European part of Russia. Possible effects of irregular intra-annual flow regime on the hydroecological safety of territories are discussed.
Interrelations between suspended matter flow of the Russian rivers belonging to the Arctic Ocean basin and their flow volumes and basin areas were studied. The parameters have shown rather stable and close correlations. Annual suspended matter flow was evaluated for medium and large rivers in their mouths and outlets, as well as the total annual flow of suspended matter into the Russian Arctic seas. Long-term and along-channel variations of water turbidity and suspended matter flow values were studied; their natural and anthropogenic causes were revealed. The results are correlated with previously published data.
Geography and ecology
Chalov S.R., Yermakova A.S., Yesin E.V. Logjams on rivers, their channel-forming and environmental role
Formation of logjams and their channel-forming role are described basing on published data about forest rivers of Russia, Europe and North America as well as the results of investigation of more than 500 rivers of the Kamchatka Peninsula. Spatial patterns of logjams distribution are revealed. The largest and the most frequent logjams are typical for the rivers of submountain regions. Logjam formation is governed by channel gradient and river size, as well as the intensity of log input to them. Characteristics of logjams for unexplored rivers could be predicted on the basis of a multiple regression model using the parameters of channel and floodplain as predictors. Within the river continuum logjams are most typical for semi-mountain and mountain rivers with well-developed alluvial forms. By blocking the rivers logjams become an active factor of restructuring this type of channels. Changes in flow hydraulics and channel morphology predetermine the influence of logjams on the structure of aquatic biotopes.
Methods of geographical research
Gennadiev A.N., Zhidkin A.P., Olson K.R., Kachinsky W.L. Erosion and organic carbon loss from soils during slope plowing
Data on the rates of erosion and accumulation processes in soils on the slopes under plough and forest/meadow-steppe vegetation were obtained using a new method of magnetic tracer. Changes in specific features of soil wash-out and deposition under different types of land use are described. Quantitative parameters of organic carbon loss from eroded arable soils on the slopes of different shape and orientation were evaluated.
Procedures for landscape-based planning of sustainable forest management have been elaborated and implemented. Potential forest habitat types were modeled on the basis of the structure of natural territorial complexes using a discriminate factor analysis method and a teaching selection of experimental data set along the transects. By this forest taxation data were georeferenced and forest strata became landscape-adapted. The results were used to model forest stands dynamics under contrasting scenarios of forest management. Analysis of forest tolerance to principal use felling in different landscapes made it possible to develop a scheme of differentiated forest management. Forest management planning according to forestry standards and with account of landscape structure provides for environment-friendly sustainable and economically efficient use of forest resources.
The dynamics of the northern forest line within the plains of the Kola Peninsula was studied in the framework of the international PPS Arctic project. QuickBird images for a Landsat pixel area of 30x30 m were analyzed for eight types of ecosystems of forest, forest-tundra and tundra zones, thus providing for the investigation of the northern forest line dynamics. It was found that poor representation of northern forests on Landsat imagery results from combined compensative effect of tree crowns and their shadows. Therefore it is necessary to study spectral features of shadows too.
Age and genetic variations of cryolithozone of the Barentz-Kara Sea shelf area has been studied. Areas with newly formed submarine permafrost were revealed along with the originally sub-aerial relic one, thus proving possibility of freezing of the bottom sediments. The mechanism of sheet ice strata formation is described. Sections with sheet ice on the shelf were compared with similar ones within the adjacent plains. Both types of sections are characterized by many similar parameters, thus proving a marine genesis of the plains of the northern regions of Western Siberia and the European North-East. Together with the adjacent shelf areas they form an integrated system with transgression-regression regime. During the Pleistocene a share of submarine and sub-aerial areas kept changing all the time, thus supporting the formation of either submarine or sub-aerial cryolithozone.
Parameters of the tidal oscillations of water level in the Great Salma-Rugozerskaya Guba estuary system in the Kandalaksha Bay of the White Sea were for the first time studied on the basis of field observations. Harmonic analysis of water level oscillations has been carried out at three sites and the spatial structure of tidal oscillations of water level in the estuary system was described. Because of morphometric features tidal oscillations of water level are rather complicated there, leading to pronounced changes of tide phases and increased importance of shallow-water waves for tide formation. Ratio of total amplitudes of quarter-diurnal and semi-diurnal tides is very high (0,2), resulting in the increased asymmetry of tides, i.e. the period of water rise is 2 to 2,5 hours longer than that of water fall. Non-tidal oscillations of water level were also studied by exclusion of tide values from the observation data and further smoothing.
Comparative assessment of soil cover features of a long-cultivated site with several runoff depressions and its intact analogue situated within the same balka catchment basin. Different degree of agrogenic transformation of soils within depressions and interdepression areas of the model plot were revealed. Principal factors of agrogenic impact resulting in the transformation of soil cover of the area under study are described.
Spatial distribution of particle-size fractions, humus, pH values, as well as Ti, Zr, Mn, Co, Zn, Cu, Pb, Cr, V, Ni, Sn, Sr and Ba in the upper horizon of soils of small erosion forms (i.e. ravine and balka) has been studied within the MSU Satino training station in the central part of the Protva River basin. Correlation of these values was analyzed using statistical procedures. Metal content (except Sr) shows positive correlation with dust fractions. The bottom of the Volchy ravine is a transit system for dust and silt fractions, while that of the Senokosnaya balka is an accumulative one. From upper to lower courses a gradual decrease of content was observed for Ba, Ti, Cr and V in bottom soils of the ravine (to a less extent for Mn, Sn and Zr) and for Ni, Cu and Sn (to a less extent for Pb) in those of the balka, thus proving their participation in the migration processes.
Golovanov D.L., Evseeva L.S. Readings in the memory of Alexander Leonidovich Chizhevsky
Druzhinin A.G., Shuvalov V.E. International Scientific Conference “Theory of Social-Economic Geography: State-of-the-Art and Prospects of Development”
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