The velocity distribution in a meandering compound channel with vegetated floodplain was very important for determining sediment transport, channel process and bank protection. The lateral distribution of depth-averaged velocity in meandering vegetated compound channels was studied. For the streamwise momentum equation, the drag force due to vegetation was added to it as a momentum sink term. And three different integral forms of turbulent diffusion term were considered and three analytical solutions to depth-averaged velocity were obtained. The effects of sinuosity and secondary flows were also taken into account. The series of experimental data of UK FCF were used to examine the three models, and the results indicated that using the optimum K values in each panel, the proposed model could predict velocity distribution better than the earlier method which ignored the secondary flow effects on floodplain. TheK values in the main channel increased significantly after the floodplain was vegetated. The predictions of three models were almost the same on the floodplain and the differences were mainly in the main channel. On a whole, the model has the best agreement with experimental data.
