Discharge assessment in an asymmetric compound channel by zero shear interface method

Abstract

Rivers are often flanked by either side floodplain and appear as an asymmetrical compound section during flood. In an asymmetrical compound section, the apparent shear stress at different interfaces varies greatly due to stronger interaction at the junction between main river section and its adjoining floodplain. In a symmetrical compound channel, the momentum transfers uniformly from main channel to both its floodplains. But in case of a compound channel with asymmetrical floodplain, there is a stronger flow interaction at the interface region. In this study, a new approach to estimate the discharge in asymmetric compound channels by adopting zero shear interfaces at the junction is described. Some approaches for predicting flow using different area methods in asymmetric channels are reported. On the basis of multi linear regression analysis, an improved area method has been proposed. The performance of proposed model is successfully validated with own experimental data and the flood channel facilities of UK data. The advantage of the current area correction model is compared well with previous methods. The applicability of the new approach in realistic situations for predicting the discharge has been precisely achieved.