A Dual Approach to Modeling Solute Transport

The classic average method is usually applied to describe the solute transport equation of one-dimensional horizontal flow or two-dimensional horizontal flow. The solute transport equation is totally integrated one time from the bed to the water surface; the average values received by classic average method do not generalize by means of dual approach. So, in this paper, a dual approach is applied to solve the solute transport equation of two-dimensional horizontal flow. The equation describing the depth average concentration is obtained by two times integration: The first time integral is from the bed to the intermediate surface lays between bed and water surface, and the second time integral is from the bed to the water surface. With the dual approach, the received depth average concentration is better, particularly, in the case of stratification, mixed solute, and so on. The received governing equation based on the dual approach describes more accurately the physical characteristic of the transport phenomena in nature. Moreover, it provides flexible parameter adjustment based on the experimental data. A case study of salinity transport in Huong river is illustrated.