The vertical distribution of suspended sediment and phosphorus in a channel with ice cover.

Abstract

Ice cover is a common channel phenomenon in some cold regions. But most of the researchers focused on the velocity distribution; the suspended sediment and phosphorus distribution in an ice-covered channel need more attention. Six different discharge treatments were carried out in this paper; and vertical velocity, suspended sediment, and phosphorus concentration were measured. The results showed, based on the convection-diffusion equation of sediment, the analytical solution of sediment vertical distribution given, and the coefficient of determination (R2) between the measured data and predicted data ranging from 0.9519 to 0.9777 and the root mean square error (RMSE) between the measured data and predicted data ranging from 0.2959 to 0.5892, that the analytical solution has a good simulation result. Particulate phosphorus concentration (Cp) is smaller in the top layer and larger in the bottom layer, and the dissolved phosphorus concentration (Cd) is larger in the middle and small in both sides; partition coefficient (Kd) is uniform in the channel which is assumed as a constant in previous studies. This result is helpful to know the retention law of suspended sediment and phosphorus in an ice-covered channel.