- Title
- Variation in suspended sediment yield across the UK : a failure of the concept and interpretation of the sediment delivery ratio
- Creator
- Worrall, Fred; Burt, Tim P.; Howden, Nicholas J. K.; Hancock, Gregory R.
- Relation
- Journal of Hydrology Vol. 519, Issue PB, p. 1985-1996
- Publisher Link
- http://dx.doi.org/10.1016/j.jhydrol.2014.09.066
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2014
- Description
- The sediment delivery ratio (SDR) has been a common approach developed to understand change in sediment yield and flux through a catchment. In this study we propose that the underlying concept of the sediment delivery ratio is flawed for a number of reasons: its linear extrapolation is physically meaningless; there is no evidence of the magnitude of storage required by the SDR approach on annual to decadal timescales; and the SDR approach assumes suspended sediment transport is conservative yet it is known to undergo both loss and production in-channel. This study considers the sediment yield from 192 UK catchments from 1974 to 2010 for catchment areas between 4 and 9948km2 and shows that linear extrapolation of the SDR approach overpredicts source terms and underpredicts fluxes for large catchments. The SDR approach hides a range of behaviours of suspended sediment flux within catchments with patterns of net deposition, net increase or no change all apparent in UK catchments. The approach proved to be self-correlated which meant that it can result in spurious correlations when compared to catchment area. The change in yield with catchment area can be just as well understood as a change in sediment supply from channels rather than as a change in delivery from hillslope sources. We propose that suspended sediment flux change with catchment area be modelled as a more physically-meaningful Gompertz function (step function) rather than using the traditional SDR approach.
- Subject
- suspended sediment flux; SDR; particulate organic matter; rivers
- Identifier
- http://hdl.handle.net/1959.13/1068156
- Identifier
- uon:18566
- Identifier
- ISSN:0022-1694
- Language
- eng
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