Dune geometry estimation using apparent bedload velocity as predictor variable

Abstract

Dune formation in river systems influences sediment transport, flow characteristics, bank erosion, flood control, navigation and the protection of land and infrastructure. Research on dunes is mainly flume-based, and conclusions from such research are rarely, if at all, verified with field measurements. Dune formation and geometry in terms of height, length and steepness is most commonly correlated with averaged flow parameters as flow depth. Application of relations defined in flume conditions is limited due to stationary flow conditions and extrapolation issues for natural watercourses. It is reasonable to assume that apparent bedload velocity has significant influence on dune field formation due to nature of movement of sand particles across sandy riverbed. This research investigates applicability of apparent bedload velocity as argument in empirical relations for dune geometric characteristics.