Department of Physical and Economic Geography
Global erosion model and sediment yield into the World Ocean: natural and anthropogenous components
Use of the database generated by authors about suspended sediment yield and the factors determining it, containing data on 4 140 river basins, has allowed to define suspended sediment load from each continent into each ocean. The suspended sediment yield into the World Ocean makes 15 469 million tons a year. Most of all sediments delivers in ocean Asia (59 %), least - Australia (1.1 %). The natural component is certain according to suspended sediment yield of the rivers which basins are not changed or are very poorly changed by activity of the human. It is equal 5 978 million tons a year. Anthropogenous component (9 491 million tons) is received by subtraction natural component from the general suspended sediment yield. Therefore, human activity has increased suspended sediment yield into oceans in 2.6 times.
The analysis of temporary numbers of specific sediment yield and other data shows, that in second half XX centuries erosion in the moderate belt of northern hemisphere tested primary easing, in tropical belt - strengthening. A primary factor of this variability is the human activity. Work was conducted at financial support of the RFBR.
Authors: Dedkov A.P., Gusarov A.V., Mozzherin V.I.
Erosion systems on the plains: their natural and anthropogenous transformations
Research object are the erosive and accumulative processes proceeding in river-bed and on a surface of river-basin. Depending on their character and intensity the concept about erosion systems is entered. As the most objective method of their modern condition studying serves the analysis of suspended sediment yield, and in the geological past - various methods of geological and geomorphological reconstructions. As a result of research it is established, that on plains of the Earth two erosion systems have received development. In first of them, named "river-bed", erosive activity concentrates in a river-bed and on its coasts which are the basic supplier of sediments. In another - "river-basin"- system erosion in a river-bed plays the subordinated role, and the great part of sediments acts from a surface of river-basin. Both systems differ among themselves with structure of river sediment, character of their transport, an alluvium structure, relationships with slope adjournment, morphology of river valleys. A primary factor supervising spatial and temporary changes of erosion systems, landscape and climatic conditions serves. Knowledge of the functioning mechanism of erosion systems allow to plan and carry out the whole complex of antierosion actions.
Authors: Dedkov A.P., Gusarov A.V., Mozzherin V.I., Mozzherin V.V.
Estimation of influence of human activity on river basins on erosive and river-bed systems in the Middle Volga region
Repeated strengthening river-basin (sheet and gully) erosion, the increase of suspended sediment yield, change of its structure, and reduction the lowest water-level in the rivers (down to full drying) as a result have led to strong degradation of the rivers in conditions of field and forest-field landscapes. It was expressed in reduction of quantity of water-currents, their length and transition of water-currents from higher order to lower. Increase of sediment yield and cover the river beds with deposits in this mechanism of degradation play the subordinated role. However the increased sediment yield together with increase in height of a high water has caused a superstructure of flood-plane alluvium by the silt-form. Speed of its accumulation is much more, than flood-plane alluvium, generated in natural landscape conditions, and time of formation keeps within an interval of economic development of river basins. Besides increase silt-form in all flood-plane thicknesses upwards on a section on the small rivers it was possible to find out slow displacement of the top alluvium horizons downwards on a river valley and from a rear part flood plane to a channel.
Authors: Kurbanova S.G., Mozzherin V.I.
Geological and geomorphological conditions of bitumens deposit formation in the basin of Middle Sheshma
Area nearly Nizhnaya Karmalka on the Sheshma-river is the unique territory of Russia where in the Quarter there was an outpouring of bitumens on a surface. The analysis of literary and archive materials, and also forwarding data, have allowed to establish the prospective reason of bitumens outpouring on a surface. Sharply expressed exotectonic displacements, connected with non-uniform static loading on bitumens sandstones horizon of Upper Permian, have created conditions for bitumens outpouring.
Authors: Dedkov A.P., Mozzherin V.V.
The mechanism and structure of chemical denudation
Chemical denudation unlike mechanical is studied much worse. As it most exact estimation can serve the drain of the dissolved substances. Its studying bases on the generated database which includes data on 1 120 hydrological posts of the Earth's rivers. On each post are established its site, period of observation, area and relief of river basin, water yield, structure of drain-breeds, landscape accessory of river basin, technogenic loading, mineralization and ionic structure of water, dissolved yield and specific dissolved yield. The analysis of a database shows, that in natural landscapes of humid areas of the moderate belt dominates chemical denudation over mechanical. Underground dissolution and leaching prevail. Agricultural activities have changed parity between chemical and mechanical denudation on behalf of the last.
On a global scale total carrying out of the dissolved substances into the World Ocean is equal 3.1 billion т in a year that makes only 25 % from all rivers sediment yield. Ash value of distribution of dissolved yield is doubtless. Two maxima of carrying out are allocated; they connected with warm and/or damp zones of moderate and subtropical-tropical belts. In one's turn they outline minima with colder or drier climate. Stronger and unequivocal influence renders a relief. To height there is a parallel strengthening of mechanical and chemical carrying out, but the first grows four times more quickly. Chemical denudation is rather sensitive to structure of drain-breeds. At the same time the landscape accessory of river basin and the anthropogenous factor influence on the dissolved yield a little.
Authors: Denmukhametov R.R., Kozhevatov E.D., Mozzherin V.I., Sharifullin A.N.
Division into districts of territory of Tatarstan on conditions of underground water formation
The basic data on 1 430 springs of Republic Tatarstan are collected and their field studying with the purpose of share definition of spring water yield in lowest water-level of runoff is lead. For the first time the major parameters of each spring (geomorphological position, structure of water-containing, covering and spreading rocks, spring output, physical properties of water, chemical compound of the dissolved substances, sanitary condition, economic use, etc., only 14 groups of parameters) are received. The electronic catalogue of springs is created, the electronic map of springs accommodation of scale 1 : 100 000 and division into districts schemes of Republic Tatarstan on conditions of springs formation and distribution is made.
Authors: Mozzherin V.I., Sharifullin A.N.