Author(s): H. Tu; B. L. Jayaratne; N. Tamai; K. Kan

Linked Author(s):

Keywords: No Keywords

Abstract: Compound channels are widely seen in the middle- and lower-reaches of many natural rivers. Since flood plains are dry areas during low discharge seasons, they are explored cither as entertainment parks, or even exclaimed by peasants as fertile farming fields in the case of some large rivers. When flood comes, however, amusement centers or crops arc sometimes inundated. It is due to flood-relieving needs or environmental concerns that flows in a channel with flood plains (compound-channel flows) have drawn increasing attention in recent years. In a laboratory flume, Rajaratnam and Ahmadi (1981) measured and investigated in great detail velocity variations across a compound channel section. Kawahara and Tamai (1989), using an algebraic stress model along with the k-E model, calculated the 3-D flow fields and studied the mechanism of the momentum transfer between the main channel and the flood plain. Knight et al. (1994) reviewed past investigations on shear stress distributions in compound channel flows. One common conclusion from these studies is that, due to momentum exchange between the flood plain flow and the main channel flow, the velocities on the flood plain are increased compared to the otherwise undisturbed ones (if without the compound section), while the velocities in the main channel are reduced.

DOI:

Year: 1995