Rating Curve Pattern in a Compound Meandering Channel Flow

Abstract

Most of the river flow in the world can be characterized as compound meandering channel in which the discharge distributions are very complex. Engineers, planners and researchers are highly interested in predicting accurately as well as reliably the quantitative estimates of discharge in a compound meandering channel. A laboratory experiment has been performed in a compound meandering channel with symmetric cross-sections having floodplain width ratio of 1.00, 1.67, 2.33, 3.00 and depth ratio of 0.20, 0.30, 0.35, 0.40 using the large-scale open air facility in the Department of Water Resources Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh. Point velocity data have been collected using an ADV (Acoustic Doppler Velocity meter) for different depth and width ratio at different locations of a compound meandering channel. Cross-sectional discharge is computed by area velocity method from the observation of velocity profile. The laboratory experiment shows that the rating curve pattern in a compound meandering channel follows the straight curve up to in bank flow and in the out bank flow it is in curvature nature.