River meander evolution under changing conditions of channel formation

Abstract

For the first time the meander evolution is traced at a large river (Vilyui) under conditions of downstream changes of the main channel-forming factors. The valley's segments with incised channel and with wide floodplain are identified. Incised meanders are typical for gentle bending (big radius of curvature) which is accounted for by high specific channel-forming discharges, high resistance of solid rocks at the banks etc. Series pattern is established in position of free meanders and curves of the dynamic axe of the stream. The series include several adjacent meanders, their curvature steadily increasing downstreams, the stream's bends curvature increases at greater rate than the curvature of the channel's meanders. Long existing bends series account for the alternation of wide and narrow segments in the lower Vilyui valley.