Estimation of river discharge using mean velocity equation

Abstract

For the improvement of the conventional stage-discharge curve equation based on just stage, this study proposed a method to estimate river discharge using hydraulic characteristics, such as hydraulic radius, bed slope, depth, etc. Hydraulic gradients in Manning's Equation and Chezy's Equation, both of which are among mean velocity equations, were computed using those characteristics. For that computation, hydrological data actually measured in a laboratory channel and a natural open channel from the Albert University Report were used. And then, river discharge was calculated using the hydraulic gradients. For comparison with the conventional method of inversely calculating roughness coefficients, their power function was formulated. And river discharge estimated using the proposed method was compared with the corresponding one estimated using stage-discharge relations. As a result, the proposed method showed results more approximate to measured discharge. An analysis of discrepancy ratio distribution revealed that non-dimensional errors lied within the ranges of -0.2 to 0.23. This indicates that river discharge estimated using the proposed method showed some improvements in accuracy, compared with river discharge estimated using the conventional stagedischarge curve equation or inverse roughness coefficients.

Versatile general elliptic open channel cross section

“…The shape of an open channel section is an important factor not only for economic reasons, but also for several aspects of channel analysis and design, including sedimentation (Park et al, 2013;Kang, 2013;Dey and Papanicolaou, 2008), probabilistic analysis (Choi and Kwak, 2001;Easa, 1994;Easa, 1992), channel roughness Azamathulla and Jarrett, 2013), and design and management (Zahiri et al, 2014;Habibi et al, 2014;Toprak et al, 2013;Azamathulla et al, 2012;Easa et al, 2011;Choo et al, 2011;Azamathulla and Ghani, 2011;Kang and Choi, 2005). This paper proposes a General Elliptic (GE) channel section that is more economical than known open channel sections, including the ordinary elliptic section by Easa and Vatankhah (2014).…”

Water flow measurements in Turkey's rivers and evaluation of alternative methods

“…Öncelikle su seviye ölçümlerine eş zamanlı olarak yapılacak hız ölçümleri ilk alternatif olarak gözükmektedir. Bunun yanı sıra hidrolik yarıçap, yatak eğimi ve pürüzlülük gibi parametrelerinde dikkate alınması debi ölçümlerinde doğruluğu artıracaktır [9,10].…”

A study on the derivation of a mean velocity formula from Chiu's velocity formula and bottom shear stress

“…What is more, Kim et al (2008) natural rivers using Chiu's velocity distribution formula and maximum velocity estimation. Choo et al (2011) developed newly discharge estimation by using the Manning and Chezy equation method reflecting hydraulic characteristics. However, these previous studies showed limitations in reflecting the hydraulic characteristics of each river and were somewhat unsatisfactory in terms of reliability.…”