CHANNEL MORPHODYNAMICS OF THE IRKUT-RIVER FOR THE LAST FORTY YEARS (UPPER PRIANGARIE)
Тhe article presents the results of the first stage of research in the framework of the monitoring project for coastal deformations of the Upper Priangarie. The main types of channel plan deformations p. Irkut (tributary of the Angara River) within the Irkutsk-Cheremkhovo Plain. Within the framework of the research, the main morphological and morphometric characteristics of the Irkut channels river within the flat-platform region (Upper Priangarie) are systematized. Quantitative data on the distribution of morphodynamic types of river beds p. Irkut. For the Irkut within the plain-platform part of the flow is characterized by the development of this type of channel. The wide floodplain type with adapted meanders, floodplain, single simple and complex bifurcations occupies 60.4 (93.3 %), of which channels with floodplain braided type – 15 km (24 %), the adapted type of channels occupies 6,7 %. On the basis of these data, a map of the distribution of morphodynamic channel types was compiled. Using the methods of geoinformation mapping, the most mobile sections of channels and the main types of horizontal deformations of channels are determined. For this purpose, different geoimages (space images, topographic maps) of the Irkut river channel were compared, the main morphometric parameters of the bends, their morphodynamic types and stages of development were measured. The most significant changes in the planned pattern of the channel occurred within the site (Maksimovshchina village – Gorky settlement) with floodplain-channel branching. It is revealed that the main deformations of the channel are associated with the dying and reformation of the transverse branches connecting the right and left anabranches. Thus, it is advisable to organize monitoring of channel and bank deformations, as well as changes in landscape components in these sections.