An Analytical Solution of the Time-dependent Profile of Suspended Sediment Concentration.

초록

The time-dependent one-dimensional vertical(1DV) conservation equation of sediment has been solved analytically on a tidal sea region. The basic advection-diffusion equatio assumes constant eddy diffusiviy and settling velocity of sediment particles. No net flux condition is set at the sea surface, while one of two kinds of bottom boundary conditions can be prescribed according to the bed condition including the sediment type. Flux-type bottom boundary condition with erosion rate and depositional velocity has been applied to mud beds, while the condition of reference concentration to sand beds. The governing advection-diffusion equation as been first transformed to a simple diffusion equation and then solved using the Galerkin-eigenfuntion method. A set of calculation has been performed to examine the evolution of the vertical structure of suspended sediment concentration, and two examples are show in Figs. 1 and 2. The solution may estimate of the erosion rate of reference concentration at the sea bottom based on the concentration information at the sea surface.