Structure of the river system as an indicator of the water capacity formation (a case study of the Selenga River basin and its delta)
E.A. ILYICHEVA1, M.V. PAVLOV1, I.Yu. AMOSOVA1,2, A.A. USHKALOV1
1V.B. Sochava Institute of Geography, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia
2Irkutsk State University, Irkutsk, Russia
Keywords: watershed, orography, digital elevation model, water-erosion systems, runoff, geomorphological zonation
Abstract
A comparative morphometric analysis of the structure parameters of the channel systems of the main tributaries of the Selenga River and its delta developing in different orographic conditions, namely: highlands, midlands and estuarine plain, was carried out. The research is based on the structural-hydrographic and basin approaches developed by domestic and foreign researchers, using materials from the space altitude model of the Earth and with the help of geoinformation mapping tools. A database of structural-hydrographic and morphometric data and estimated runoff values has been created. The studies are mainly of fundamental importance, aimed at identifying interrelated elements of the structure of river systems and conditions of their formation and development, expressed in orographic and morphostructural features of the basin. The applied aspect of the calculations consists in the assessment of average annual and forecasted potential runoff within the framework of insufficient availability and duration of observations at unevenly placed sites of the standard observation network in the transboundary territory of Russia and Mongolia. The developed model for calculating the maximum possible runoff may be useful for recommendations on rational and safe land use planning in the basin, as well as for preventing natural risks. The purpose of the research is to identify and compare structural, morphological and natural indicators of runoff in different altitudinal belts within the Selenga basin and in its individual parts. Zoning of the basin by runoff-forming areas is presented in relation to the previously developed natural zoning of the territory, their hypsometric position and morphostructural elements of the structure. A forecast model for calculating the runoff of unstudied rivers is presented.
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