PREDICTING SEDIMENTGRAPHS FOR A SMALL AGRICULTURAL CATCHMENT

The key components of a sedimentgraph prediction procedure for small a gricultural catchments are outlined in the paper. An instantaneous uni t sedimentgraph (IUSG) based on the IUH and on a dimensionless sedimen t concentration distribution is developed, and used for transforming t he sediment produced during a specified rainfall duration into a sedim entgraph. Rainfall-runoff-suspended sediment transport data from the R iver Dart basin, in Devon, UK, are used to evaluate several relationsh ips for sediment yield estimation. The relationship between the lag ti me of the direct runoff hydrograph and the sedimentgraph is analysed, and the use of these lag times for estimating an IUSG (sediment routin g) parameter is examined. The effectiveness of the proposed sedimentgr aph prediction procedure is demonstrated by the successful regeneratio n of a measured sedimentgraph.