RELATIONSHIP BETWEEN MANNING ROUGHNESS COEFFICIENT AND FLOW DEPTH IN BANGLADESH RIVERS

Authors

  • Ahanaf Tahmid Department of Civil Engineering, Ahsanullah University of Science and Technology, Dhaka, Bangladesh
  • Md. Hasanur Rahman Department of Civil Engineering, Ahsanullah University of Science and Technology, Dhaka, Bangladesh
  • Sadia Mounota Department of Civil Engineering, Ahsanullah University of Science and Technology, Dhaka, Bangladesh
  • Khan Abid Ahsan Department of Civil Engineering, Ahsanullah University of Science and Technology, Dhaka, Bangladesh

DOI:

https://doi.org/10.11113/mjce.v33.17363

Keywords:

Manning’s n, water depth, natural channel/waterway, Bangladesh river, regression equation.

Abstract

Manning's n is the most widely used resistance coefficient for open channel flows. There are several factors that affecting the variation of roughness coefficient in open channels such as surface roughness, bed material, channel alignment, shape irregularity and vegetation. The prediction of the variation of the roughness coefficient in a natural waterway becomes more complex and challenging task to hydraulics engineers until now. The main emphasis of this research is the assessment of the Manning coefficient of riverside roughness, which is used in hydraulic simulations and to explore the link between the coefficient of Manning and water depth The aim of this study was to investigate the correlation/relationship between flow depth and Manning's n for several selected rivers in Bangladesh. This research represents graphically the connection between roughness coefficient of Manning and water depth of year 2019 based on the collected data's (cross section, discharge, stream width) from Bangladesh Water Development Board (BWDB). The main focus of this research was to establish the regression equations by graphically plotting calculated Manning's n versus flow depth. The relationship between the two variables in the stations is shown to be directly proportional, while some are inversely proportional, by changing water depth and computing Manning roughness coefficient. It can be seen that most stations have more than one behavior, i.e., the connection between these parameters is directly related in certain periods all through the year, while it is inversely proportional with others. The findings prevail that the Manning's n varied from 0.01 s/m1/3 to 0.14 s/m1/3 for a comparable depth of 1m to 20m at all the stations being studied here and 6th order polynomial equation observed R2 is between 0.9288 and 0.9943 for most of the stations being studied here which may provide an efficient prediction evaluation in estimating Manning roughness coefficient.

References

Parsaie, A.; Najafian, S.; Omid, M. H.; Yonesi, H. 2017. Stage discharge prediction in heterogeneous compound open channel roughness. Journal of Hydraulic Engineering, 23(1): 49 56. http://dx.doi.org/10.1080/09715010.2016.1235471

Kim, Y.; Tachikawa, Y.; Shiiba, M.; Kim, S.; Yorozu, K.; Noh, S. J. 2013. Simultaneous estimation of inflow and channel roughness using 2D hydraulic model and particle filters. Journal of Flood Risk Management, 6(2): 112-123. http://dx.doi.org/10.1111/j.1753 318X.2012.01164.x

Kopecki, I.; Schneider, M.; Tuhtan, J. A. 2017. Depth dependent hydraulic roughness and its impact on the assessment of hydropeaking. The Science of the Total Environment,.575(1): 1597-1605

Zink, J. M.; Jennings, G. D. 2014. Channel roughness in North Carolina mountain streams. Journal of the American Water Resources Association. 50(5): 1354 1358,

AYVAZ, M. T. A 2013. linked simulation-optimization model for simultaneously estimating the Manning’s surface roughness values and their parameter structures in shallow water flows. Journal Hydrology. 500: 183-199, http://dx.doi.org/10.1016/j.jhydrol.2013.07.019

Fard, R. S.; Heidarnejad, M.; Zohrabi, N. 2013. Study factors influencing the hydraulic roughness coefficient of the Karun river(Iran). International Journal of Farming and Allied Sciences, 22(2): 976-981,

Calo, V. M.; Collier, N.; Gehre, M.; Jin, B.; Radwan,H.; Santillana, M. 2013. Gradient-based estimation of Manning’s friction coefficient from noisy data. Journal of Computational and Applied Mathematics, 238: 1-13, http://dx.doi.org/10.1016/j.cam.2012.08.004.

Chow, V. T. 1959. Open channel hydraulics. New York: McGraw-Hill

Prajapati, P. R.; Vadher, B. M.; Yadav, S. M. 2016. Comparative analysis of hydraulic roughness coefficient at Purna River sites. Global Research and Development Journal for Engineering, 1(4): 574 579,

Halim, M. A. 2010. Roughness characteristics of alluvial rivers of Bangladesh. The AUST Journal of Science & Technology. 2(2): 1-11 ISSN 2072-0149,

Chaudhry, M. H. 1993. Open Channel Flow. Prentice-Hall International, Inc., Englewood Cliffs,

Khan, H. R., 1975, “Roughness coefficients of some rivers of Bangladesh,” Journal of the nstitution of Engineers Bangladesh,2(4): 105-112.

Delft Hydraulics/DHI, 1996, “River Survey Project (FAP-24),” Report on Sedimentology.

French, R. H., 1986, “Open Channel Hydraulics,” McGraw-Hill Company Limited, London.

Uddin, M, L., 1999, “Applicability of alluvial roughness predictors for the rivers Gumti, Kushiyara and Mahananda,” Thesis presented to the Bangladesh University of Engineering and Technology, Dhaka, in partial fulfillment of the requirements for the degree of Master or Engineering in Water Resources.

Alam. S., 1998, “Applicability of alluvial roughness predictors for the river Ganges,” Thesis presented to the Bangladesh University of Engineering and Technology, Dhaka, in partial fulfillment of the requirements for the degree of Master of Science in Water Resources Engineering.

R.N. Fahim et al., “Applicability of alluvial roughness predictors for Dharala river,” Thesis presented to the Ahsanullah University of Science & Technology, Dhaka, in partial fulfillment of the requirements for the degree of Bachelor of Science in Civil Engineering.

Nezu I., Nakayama T., 1997. “Space–time correlation structures of horizontal coherent vortices in compound channel flows by using particle-tracking velocimetry.” J Hydraul Res, 35(2): 191–208

Brito M., Fernandes J., Leal J.B., 2016. “Porous media approach for RANS simulation of compound open-channel flows with submerged vegetated floodplains.” Environ Fluid Mech, 16(6): 1247–1266. https://doi.org/10.1007/s10652-016-9481-0

H. Hooman et al., 2010. “Assessment of manning’s resistance coefficient in compound channels.” Journal of Water Sciences Research, 2(1): 9-20, ISSN: 2008-5338.

Lane, E. W., Carlson, E. J., 1953. “Some factors affecting the stability of canals constructed in coarse granular materials.” Proceedings of the Minnesota International Hydraulics Convention, ASCE-IAHR Joint Meeting, Minneapolis, MN, 1-4 (September): 37-48.

Hey R. D., 1979. “Flow resistance in gravel bed rivers.” Journal of hydraulic Div., ASCE, 105(HY4), Proc. Paper 14500; 365-379.

Bray D.I., 1979. “Estimating average velocity in gravel-bed rivers.” Journal of Hydraulic Div. ASCE, 105(HY9), Proc. Paper 14810; 1103-1122.

Robertson, B.A., Cassidy, J.J., Rutherfurd, I., 2000. “Towards an Australian handbook of stream roughness coefficients.” Journal of Hydraulics Engineering.

Sturm, T.W., 2001. “Open channel hydraulics.” United States of America. The McGraw Hill Companie.

Tahmid, A., Rahman, M. H., & Ahsan, K. A., 2021. “Chezy's resistance factor variations in different Bangladeshi rivers using the Bazin formula for measuring discharge.” Proceedings of International Conference on Planning, Architecture & Civil Engineering, 09 - 11 September 2021, Rajshahi University of Engineering & Technology, Rajshahi, Bangladesh.

Downloads

Published

2021-11-29

Issue

Section

Articles

How to Cite

RELATIONSHIP BETWEEN MANNING ROUGHNESS COEFFICIENT AND FLOW DEPTH IN BANGLADESH RIVERS . (2021). Malaysian Journal of Civil Engineering, 33(3). https://doi.org/10.11113/mjce.v33.17363