Interaction of Flow and Estimation of Discharge in two Stage Meandering Compound Channels

Abstract

Reliable estimates of discharge capacity are essential for the design, operation, and maintenance of open channels, more importantly for the prediction of flood, water level management, and flood protection measures. In nature, most rivers tend to be of compound sections as well as meandering. For the management of rivers and floodplains, it is important to understand the behavior of flows within compound channels. Cross sections of these compound channels are generally characterized by deep main channel bounded by relatively shallow flood plains at one or both sides. At low depths when the flow is only in the main channel, conventional methods are generally used to assess discharge capacity. When the flow goes over bank, the classical single channel formula gives large error between the estimated and the observed discharge. Standard sub-division and composite roughness methods given in Chow (1959) are essentially flawed when applied to compound channels. The discharge calc...