Abstract
The resistance and flow structures are studied experimentally in compound open channel flows with trees on the flood plains. Compound roughness coefficient increases in proportion to the number of rows of trees, but the resistance is larger in the case of inside rows than the bank-side rows. The arrangement of inside rows of trees increases the velocity near the bank. The interaction between the flow in trees and ambient flow generates characteristic 3-D flow structures. The depth-averaged features are reasonably predicted by the numerical calculation of the transverse momentum transport equation.
