Floodplain influence on the channel landforms evolution (a case study of the Lena drainage basin)

Abstract

Floodplains influence channel deformations 1) by sediments exchange between channel and floodplain in the course of the latter formation and also due to the floodplain's scarps erosion during floods. and 2) by the floodplain's and channel's streams interaction, In the latter case the shallows development is mostly affected, depending on the character of contact between the streams, on the river's hydrological regime, configuration and size of the floodplain's segments and their relief and vegetation. The floodplain impact on the shallows evolution is most pronounced on the rivers having broad meadow floodplain with troughs and islands, where floodplain and channel streams intercross during frequent floods. Besides, the influence is clearly seen in the river channel where meandering is restricted and floodplain's segments are arranged in staggered order. On the whole, floodplains facilitate formation of more complicated channel landforms.