Forecasting sediment distribution in reservoirs during unstable conditions

A method for rapid estimation of slopes of deposited sediment in reservoirs during unstable conditions is presented. As the limiting factor determining sediment load in a reservoir is the sediment carrying capacity of a current flowing through a reservoir, it is arqued that the slope of deposited sediment must be a function of the latter. After deriving an equation relating sediment slope to stream power, the latter being regarded as representative of sediment carrying capacity, a comparison between calculated and observed sediment slopes for average annual conditions in two South African reservoirs are presented. Using this equation as basic guideline, a semi-empirical graph is then presented which relates sediment slope to a factor representing average stream power in reservoirs.