Premium
A comparison between flume and field bed load transport data and consequences for surface‐based bed load transport prediction
Author(s) -
Recking A.
Publication year - 2010
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2009wr008007
Subject(s) - flume , bed load , power function , range (aeronautics) , flow (mathematics) , geotechnical engineering , sediment transport , mechanics , geology , surface (topology) , hydrology (agriculture) , mathematics , geometry , materials science , sediment , mathematical analysis , physics , geomorphology , composite material
The ability of simple equations to predict bed load transport with limited knowledge of the bed surface material was investigated. This was done using a data set consisting of 7,636 bed load transport values from the flume (1,317 data) and from 84 river reaches (6,319 field data). It was possible to collapse field and flume data by correcting the ratio between the Shields number and its critical value with a very simple hiding function proposed as a power law of the D 84 / D 50 ratio. In so doing, a surface‐based bed load transport formula was proposed. It was successfully tested on an independent data set (comprising sand and gravel bed rivers with slope in the range 0.0002–0.08), with 86% of the values predicted within a precision of 1 order of magnitude. Moreover, the formula reproduced the low transport rates well, contrary to the usual surface‐based formulas also tested, and is particularly well suited for estimating low transport rates associated with near‐bankfull flow discharge. This new formula is neither time consuming (no fractionwise calculation) nor data consuming (the required parameters are the flow discharge, the active width, the slope, and the surface grain diameters D 50 and D 84 ).