Study of flow in a non-symmetrical compound channel with rough flood plain

Abstract

The practical interest to study the flow in compound channel section arises from the necessity for accurate discharge predictions during flood events and for a reliable stage discharge relation for flood control measures and management schemes. It has been long realized that traditional hydraulic methods of channel subdivision are inadequate for discharge calculation due to the significant interaction between main channel and flood plain that previously rarely taken into account of. This paper presented the results of experimental investigations carried out on a small scale non-symmetrical compound channel with rough flood plain in order to compare the different methods available for discharge prediction in a compound channel. The weighted divided channel method (WDCM) has been used to check the validity of the horizontal division method and the vertical division method in predicting discharge. Results from this experimental investigations have shown that for non-symmetrical compound channel with wider flood plain, the horizontal division method provide the more accurate predictions of discharge while for narrower flood plain, the vertical division is more accurate.