A FINITTE ELEMENT MODEL FOR THE SIMULATION OF SUSPENDED SEDIMENT TRANSPORT IN STREAM SYSTEMS*

A finite element model that simulates erosion, transport, and deposition of suspended sediment, as well as suspended organic matter, is developed. This dynamic mathematical and computer model is formulated to simulate concentration of suspended organic matter and suspended mineral sediment in stream systems, with inflow from point and nonpoint sources. Standard Galerkins* weighted residual method is used for variational formulation of advection-diffusion equation which is the statement of mass balance. The domain is divided into a series of linear quadratic or cubic isoparametric interpolation elements. The solution of the equations is stable and convergent unconditionally for the range of peclet numbers encountered in stream systems. The model was verified by using data from the 30 km reach of the Colusa Basin Drain. ITie finite element solution of the model is also compared with the mathematical solution by a finite difference implicit method. The simulated results are in good agreement with measured values.