Determining the rating curves in asymmetric compound channels

Document Type : Research Article

Authors

1 Department of Civil Eng. Ferdowsi University of Mashhad

2 water and science engineering Dept. Ferdowsi university of mashhad

Abstract

Generally, natural open channels have sections in which by increasing the water level, the crosssectional area will be increased considerably. These sections have consisted of relatively wide floodplains. In compound channels with asymmetric cross-sections, the hydraulic behavior of the flow would be complicated. Rating curves estimation in compound channels is one of the most critical issues of river engineering. In the current study, a new approach based on the concept of the crosssectional isovel contours is introduced for the estimation of rating curves in compound channels. To extract the exponent values of the governing parameters, minimization approach is used to the difference between the observed and estimated data. In this method, in order to set up the rating curves in various cross-sections, it is only requisite to have the flow information at a reference water level. The results show that the proposed method has a good accuracy for predicting rating curves in asymmetric compound channels even in compound channels with different floodplain levels.

Keywords


سلطانی، ع.؛ علیائی؛ ا. و قربانی، م.؛ (1389). "مدل‌سازی رابطه دبی- اشل در رودخانه‌ها با استفاده از سیستم‌های هوشمند". دانش آب و خاک، جلد 1، ص.ص. 15-30.
ظهیری، ع.؛ دهقانی، ا.ا. و جریبی، ا.ه.؛ (1391). "تعیین رابطه دبی- اشل برای مقاطع مرکب آزمایشگاهی و صحرایی با استفاده از الگوریتم ژنتیک". مجله پژوهش‌های حفاظت آب و خاک، جلد 19، ص.ص. 179-191.
Abril, J.B. and Knight, D.W., (2004). "Stage-discharge prediction for rivers in flood applying a depth-averaged model". Journal of Hydraulic Research, 42(6): 616-629.
DOI:10.1080/00221686.2004.9628315
Ackers, P., (1993). "Stage‐Discharge Functions for Two‐Stage Channels: The Impact of New Research". Water and Environment Journal, 7(1): 52-59.
Ahmadi, A., Kavousizadeh, A. and Maghrebi, M.F., (2017). "Setting-up rating curves in natural rivers using an efficient method", International Conference on the Status and Future of the World's Large Rivers, New Delhi, India.
Chen, Y.-C. and Chiu, C.-L., (2002). "An efficient method of discharge measurement in tidal streams". Journal of hydrology, 265(1): 212-224.
Habib, E.H. and Meselhe, E.A., (2006). "Stage–discharge relations for low-gradient tidal streams using data-driven models". Journal of Hydraulic Engineering, 132(5): 482-492.
DOI:10.1061/(ASCE)0733-9429(2006)132:5(482), 482-492.
Knight, D., (1992). "SERC flood channel facility experimental data phase A". Hydraulic Research Wallingford, 198-204.
Knight, D.W. and Demetriou, J.D., (1983). "Flood plain and main channel flow interaction". Journal of Hydraulic Engineering, 109(8): 1073-1092.
Knight D., McGahey C., Lamb R. and Samuels P. (2009). Practical channel hydraulics: Roughness, conveyance and afflux: CRC Press.
Lambert, M. and Myers, W., (1998). "Estimating the discharge capacity in straight compound channels". Proceedings of the Institution of Civil Engineers. Water, maritime and energy,130(2):84-94. DOI:10.1680/iwtme.1998.30477
Leonard, J., Mietton, M., Najib, H. and Gourbesville, P., (2000). "Rating curve modelling with Manning's equation to manage instability and improve extrapolation". Hydrological Sciences Journal, 45(5): 739-750.
DOI:10.1080/02626660009492374
Liao, H. and Knight, D., (2007). "Analytic stage-discharge formulas for flow in straight prismatic channels". Journal of Hydraulic Engineering, 133(10): 1111-1122.
Maghrebi, M.F. (2006). "Application of the single point measurement in discharge estimation". Advances in Water Resources, 29(10):1504-1514. DOI:10.1016/j.advwatres.2005.11.007
Maghrebi, M.F. and Ahmadi, A., (2017). "Stage-discharge prediction in natural rivers using an innovative approach". Journal of Hydrology, 545:172-181. DOI:10.1016/j.jhydrol.2016.12.026
Maghrebi, M.F., Kavousizadeh, A., Maghrebi, R.F. and Ahmadi, A., (2017). "Stage–discharge estimation in straight compound channels using isovel contours". Hydrological Processes, 31(22): 3859-3870.
DOI:10.1002/hyp.11299
Sahu, M., Khatua, K.K. and Mahapatra, S.S., (2011). "A neural network approach for prediction of discharge in straight compound open channel flow". Flow Measurement and Instrumentation Journal, 22(-): 438-446.
DOI: 10.1016/j.flowmeasinst.2011.06.009
Shiono, K. and Knight, D., (1991). "Turbulent open-channel flows with variable depth across the channel. Journal of Fluid Mechanics", 222:617-646. DOI:10.1017/S0022112091001246.