Contact us
 |
[email protected] |
 |
3275638434 |
 |
 |
| Paper Publishing WeChat |
Useful Links
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Article
Evaluating Methods for Discharge Prediction of Straight Asymmetric Compound Channels
Author(s)
Xiaonan Tang
Full-Text PDF
XML 538 Views
DOI:10.17265/2328-2193/2018.05.004
Affiliation(s)
Department of Civil Engineering, Xi'an Jiaotong-Liverpool University, Suzhou 215123, China
ABSTRACT
Accurate prediction of flow discharge in a compound channel is
increasingly important in river flood risk management. This paper evaluates
four most recently developed 1-D methods for discharge prediction. The four
methods, which have considered the impact of momentum exchange, are Interacting
Divided Channel Method (IDCM), Momentum-Transfer Divided Channel Method
(MTDCM), Modified Divided Channel Method (MDCM) and Apparent Shear Stress
Method (ASSM). The four methods are compared with 20 experimental datasets from
the author and the literature. These datasets include both homogeneous (8
datasets) and heterogeneous (12 datasets) asymmetric compound channels, which
have various width ratios (B/b) of 1.5 ~ 5 [channel total width B at bankfull / main channel bottom b] and bed slopes of 2.65×10-4 to 1.3×10-2. This study shows that the four methods performed
reasonably well (in averaged errors < 6.5%) against all the datasets except
in a very steep channel with high width ratio (e.g. B/b ≥ 5 in So = 0.013), particularly with improved discharge predictions of main channels
compared with conventional divided channel method (DCM). It appears that the
MDCM shows the best overall performance for homogeneous channels whereas all
four methods perform similarly for heterogeneous compound channels. Close
examination reveals that the error percentage by all four methods increases as
increasing width ratio (B/b) for roughened
floodplain channels, but it seems in reverse for homogeneous channels. Finally,
all four methods have shown improved flow predictions of main channels compared
with the DCM.
KEYWORDS
Overbank flow, compound channel, asymmetric compound channel, open channel, momentum exchange.
Cite this paper
References