Home – Home – Jornals – Geography and Natural Resources 2022 number 1

Based on analyzing geomorphometric indicators of the floodplain relief of the Iya-river valley, we identified specific features in the distribution of flows during flooding within different morphological areas. A digital elevation model was used in calculating the horizontal and vertical curvature of the valley of the Iya-river, and for representing their distribution in space, maps were compiled for a number of key areas that were located within the development of the wide-floodplain, the adapted and inscribed types of channel. It was revealed that the distribution of flows within the wide-floodplain area, in addition to the width of the floodplain, was influenced by the development of segment and hollow-island floodplains, as well as the general predominance of wetland flat surfaces which are zones of accumulation, which contributed to the retention of water within this area. In the downstream section with the adapted channel, the curvature of the surface did not play a significant ole in the distribution of flows. The position of this segment between the two extended sections of the valleys, and also a complex combination of forced bends, served as an additional factor in the concentration of flow in the narrow valley and the development of “areal erosion”, which led to significant material damage. A part of the city of Tulun is located in the spur of an adapted bend with fairly flat floodplain surfaces, which contributed to the spreading of the stream. The change of the downstream channel type from a broad-bottomed to an adapted one could provoke back water and retention within the urban area.