A Method for Improving Stage Discharge Prediction in Asymmetric Compound Channels

Tang, Xiaonan ORCID: 0000-0002-2434-9341 (2018) A Method for Improving Stage Discharge Prediction in Asymmetric Compound Channels. In: 2018 International Conference on Environmental and Water Resources Engineering, 2018-10-12 - 2018-10-14, Jeju Island, Korea.

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Abstract

In nature, asymmetric compound channels widely exist. Accurate prediction of stage-discharge in an asymmetric compound channel becomes increasingly important in flood risk management and river environmental engineering. To predict discharge precisely, momentum exchange between the main-channel and its floodplains needs to be considered. Currently, Interacting Divided Channel Method (IDCM) has considered such exchange, but has certain errors for asymmetric compound channels, particularly for roughened floodplains. In this paper, the author proposes a new parameter of IDCM to improve flow discharge prediction. The proposed method is evaluated by a range of experimental data from the literature. 20 datasets studied include both homogeneous asymmetric compound channels (8 datasets) and heterogeneously roughened channels (12 datasets), which have different aspect ratios [the ratio of total width (B) of channel at bankfull to main-channel bottom (b) =1.5 ~ 5] and bed slopes (So = 2.65x10-4~ 1.3x10-2). This study shows that the method of using the new parameter performs well (in average errors less than 6.5%) against all the datasets except in a very steep channel with high aspect ratio (e.g. B/b ≥ 5 in So = 0.013). Close analysis shows that the proposed method can predict the zonal discharge ratio well for both homogeneous and heterogeneous compound channels. Finally, this method has also shown improved stage-discharge predictions of main channels over the conventional divided channel method (DCM).

Item Type:	Conference or Workshop Item (Unspecified)
Additional Information:	Water Resources and Ecological Carrying Capacity
Uncontrolled Keywords:	overbank flow, compound channel, asymmetric compound channel, stage discharge, momentum exchange
Depositing User:	Symplectic Admin
Date Deposited:	21 Oct 2021 07:37
Last Modified:	18 Jan 2023 21:26
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3141041