Deposition in Terraces
ØDeposition occurs when sediment load is greater than transport capacity
ØSediment load from sediment entering from overland area
ØTransport capacity function of grade and storm erosivity
ØDeposition depends on sediment characteristics
ØDeposition enriches sediment in fines
n
For deposition to occur, sediment load must exceed transport capacity.
Deposition, including fraction of sediment load) in a terrace channel will be much less when little erosion occurs on inter-terrace interval.
Transport capacity decreases with grade of terrace channel and runoff rate in channel.
Deposition enriches the sediment load in fines.
The amount of deposition depends on the fineness of sediment coming into terrace channel.
For example, deposition will be less in a terrace where a grass strip immediately adjacent to the terraces induces significant deposition.
Maintenance required because of deposition.  Otherwise terrace channels fill with sediment.