The estimation of river discharge by using the mean velocity equation in a unsteady condition

평균유속공식을 이용한 부정류 하천유량 산정

  • Choo, Tai Ho (Dept. of Environmental and civil Engineering, Pusan National University) ;
  • Chae, Soo Kwon (Dept. of Environmental Health and Safety, Eulji University) ;
  • Yoon, Hyeon Cheol (Dept. of Environmental and civil Engineering, Pusan National University) ;
  • Yun, Gwan Seon (Dept. of Environmental and civil Engineering, Pusan National University)
  • 추태호 (부산대학교 사회환경시스템공학부) ;
  • 채수권 (을지대학교 보건환경안전학과) ;
  • 윤현철 (부산대학교 사회환경시스템공학부) ;
  • 윤관선 (부산대학교 사회환경시스템공학부)
  • Received : 2013.10.28
  • Accepted : 2013.12.05
  • Published : 2013.12.31


As the average indicator for amount of water flowing in any cross section of a river, the mean discharge has been reported to be a very important factor for examining water circle constructions in a river basin, the design and construction of a hydraulic structure, and water front area use and management. The stage-discharge curve based on discharge and stage data measured in a normal season were basically derived. Using this derivation, the necessary discharge data was obtained. The values produced in this manner corresponded to the measured data in a uniform flow state well, but showed limited accuracy in a flood season (unsteady flow). In the present paper, the mean velocity in unsteady flow conditions, which exhibited loop form properties, was estimated using the new mean velocity formula derived from Chiu's 2-D velocity. The results of RMSE and Polar graph analyses showed that the proposed equation exhibited approximately nineteen times the accuracy compared to the Manning and Chezy equations.


Manning and Chezy equations;Mean velocity equation;Rating curve;River discharge;Unsteady flow


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