Submitted to: Integrated Water Resources Planning Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 7, 1995
Publication Date: N/A
Interpretive Summary: Accurate predictions of the amount of sand and gravel being moved by flowing water in a stream channel are important for several reasons. The sand and gravel material moving past a given location is part of the net erosion from the area upstream of the location. Sand and gravel that is moved downstream may fill channels, which decreases their capacity to convey flood waters and impedes navigation. Sand and gravel may also fill reservoirs, which decreases their storage capacity. Any channel management program must take into account the movement of sand and gravel through the system. Supplies of sand and gravel to the system and the capacity of the channels to move the sand and gravel must be balanced or instability of the channels will result. Channel instability may cause the banks of the stream to collapse or sand and gravel to be deposited on the land surface, either of which may destroy valuable agricultural lands adjacent to a stream. This paper provides a test for a recently developed technique to predict the movement of sand and gravel in streams. Predictions from the technique were reasonably close to measured rates of sand and gravel movement. This predictive technique will be a useful tool to aid in the management of channel systems.
Technical Abstract: An important aspect in the evaluation of channel stability is the accurate prediction of the rate and size of the bed material load. Any long term program of channel stabilization must take into account the transport of sediment through the watershed. An imbalance between supply and transport capacity of sediment will cause channel adjustment or instability to occur. In streams which contain an appreciable percentage of gravel in the bed material, as in Goodwin Creek, determination of the transport rate of the different size fractions is important to determine whether bed surface armoring will develop with time. In this study predictions of the bed material load from a recently published sediment transport algorithm were compared to measured sediment transport data collected in a laboratory flume and a natural stream channel. The predictions of the transport algorithm were very close to the sediment transport data collected in the laboratory. Predictions of sediment transport for the field stream were good but not as close as for the laboratory data.