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Mean Velocity Distribution of Natural Stream using Entropy Concept in Jeju

엔트로피 개념을 이용한 제주도 상시하천의 평균유속분포 추정

  • Yang, Se-Chang (Jeju Special self-governing provincial council) ;
  • Yang, Sung-Kee (Department of Civil Engineering, Jeju National University) ;
  • Kim, Yong-Suk (Department of Civil Engineering, Jeju National University)
  • Received : 2019.01.28
  • Accepted : 2019.05.31
  • Published : 2019.06.30

Abstract

We computed parameters that affect velocity distribution by applying Chiu's two-dimensional velocity distribution equation based on the theory of entropy probability and acoustic doppler current profiler (ADCP) of Jungmun-stream, Akgeun-stream, and Yeonoe-stream among the nine streams in Jeju Province between July 2011 and June 2015. In addition, velocity and flow were calculated using a surface image velocimeter to evaluate the parameters estimated in the velocity observation section of the streams. The mean error rate of flow based on ADCP velocity data was 16.01% with flow calculated using the conventional depth-averaged velocity conversion factor (0.85), 6.02% with flow calculated using the surface velocity and mean velocity regression factor, and 4.58% with flow calculated using Chiu's two-dimensional velocity distribution equation. If surface velocity by a non-contact velocimeter is calculated as mean velocity, the error rate increases for large streams in the inland areas of Korea. Therefore, flow can be calculated precisely by utilizing the velocity distribution equation that accounts for stream flow characteristics and velocity distribution, instead of the conventional depth-averaged conversion factor (0.85).

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References

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