A sediment-delivery ratio is computed based on the sediment load, the size and density of particles reaching the terrace channel, and the transport capacity of the flow in the channel.
The sediment-delivery ratio for concave hillslopes is usually less than 1 due to deposition of sediment in the lower, basal portion of the hillslope (Meyer and Romkens, 1976).
06 will not compute a sediment-delivery ratio for hillslope gradients steeper than 15% because the performance of runoff barriers on steeper hillslopes has not been firmly established.
Soil loss from hillslopes can be multiplied by the sediment-delivery ratio to estimate the sediment discharged into a sediment pond.
On the other hand, the enrichment of fine-size particles reduces the trap efficiency of the pond or basin and increases the sediment-delivery ratio.
Each pond or basin in the series removes a greater proportion of the large-size particles remaining in suspension than the very fine-size particles, hence, enriching the proportion of fine-size particles and increasing the sediment-delivery ratio.