Suspended Sediment Concentration in Open Channels Using Tsallis Entropy

Abstract

Concentration of suspended sediment is of fundamental importance in environmental management, assessment of best management practices, water quality evaluation, reservoir ecosystem integrity, and fluvial hydraulics. Assuming time-averaged sediment concentration along a vertical as a random variable, a probability distribution of suspended sediment concentration is derived by maximizing the Tsallis entropy subject to the constraint given by the mean concentration and under the assumption that the sediment concentration is zero at the water surface. For deriving the sediment concentration profile along the vertical, a nonlinear cumulative distribution function is hypothesized and verified with observed data. The derived sediment concentration profile is tested using experimental and field data; however, the clear water surface assumption does not seem to be valid for field data. The Tsallis entropy-based concentration profile method is compared with three sediment concentration profile methods. Comparison shows that the Tsallis entropy-based method is, in general, more accurate than these three methods when judged by the root mean square deviation (RMSD) from observations.