A simplified method for estimating the longitudinal dispersion coefficient in ecological channels with vegetation

The longitudinal dispersion coefficient is an important parameter for describing the transport processes in rivers. Riparian vegetation significantly influences the velocity profile and transport processes. This paper examines the longitudinal dispersion coefficient under the condition that rigid emergent vegetation grows symmetrically along the river bank. We build a three-zone model by extending the N-zone models of Chickwendu and Boxall & Guymer. We also analyze the velocity profiles that are significantly affected by vegetation to estimate the parameters in our model. Our tests using the experimental data from a series of experiments validate the acceptable accuracy of our three-zone model.