ABSTRACT
The present paper is concerned with experimental observations of flow properties and bedload sediment transport in the main channel of an asymmetric compound channel, roughened with cylindrical elements as vegetation on the floodplain. The observations confirm previous experiments that roughening the floodplain shift the maximum streamwise velocity region further towards main channel wall. Also, calculating bed shear stress demonstrates local minima and maximum near junction and main channel walls respectively, the consequence being three dimensional bedforms that under the effect of secondary currents reveal larger scouring depth near the junction wall. Also, measurement of bedload rate under equilibrium conditions showed that by roughening the floodplain, the bedload discharge increases to almost 1.5 times of that without vegetation.
