Journal of Environmental Science International (한국환경과학회지)

The Korean Environmental Sciences Society (한국환경과학회)
권호 표지
DOI QR코드

DOI QR Code

Error Analysis for Electromagnetic Surface Velocity and Discharge Measurement in Rapid Mountain Stream Flow

산지하천의 전자파 표면유속 측정에 기반한 유량 및 유속 관측 오차 분석

  • Kim, Dong-Su (Department of Civil & Environmental Engineering, Dankook University) ;
  • Yang, Sung-Kee (Department of Civil Engineering, Jeju National University) ;
  • Jung, Woo-Yul (Department of Civil Engineering, Jeju National University)
  • Received : 2013.11.18
  • Accepted : 2014.04.07
  • Published : 2014.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Fixed Electromagnetic Wave Surface Velocimetry (Fixed EWSV) has been started to be used to measure flood discharge in the mountain stream, since it has various advantages such that it works well to continuously measure stream discharge even in the night time as well as very strong weather. On the contrary, the Fixed EWSV only measures single point surface velocity, thus it does not consider varying feature of the transverse velocity profile in the given stream cross-section. In addition, a conventional value of 0.85 was generally used as the ratio for converting the measured surface velocity into the depth-averaged velocity. These aspects could bring in error for accurately measuring the stream discharge. The capacity of the EWSV for capturing rapid flow velocity was also not properly validated. This study aims at conducting error analysis of using the EWSV by: 1) measuring transverse velocity at multiple points along the cross-section to assess an error driven by the single point measurement; 2) figuring out ratio between surface velocity and the depth-averaged velocity based on the concurrent ADCP measurements; 3) validating the capacity of the EWSV for capturing rapid flow velocity. As results, the velocity measured near the center by the fixed EWSV overestimated about 15% of the cross-sectional mean velocity. The converting ratio from the surface velocity to the depth-averaged velocity was 0.8 rather than 0.85 of a conventional ratio. Finally, the EWSV revealed unstable velocity output when the flow velocity was higher than 2 m/s.

Keywords

References

  1. Cheng, R. T., Gartner, J. W., 2003, Complete velocity distribution in river cross-sections measured by acoustic instruments, Proceedings of the IEEE/DES 7th Working Conference in Current Measurement Technology, 21-26.
  2. Creutin, J. D., Muste, M., Li, Z., 2002, Traceless Quantitative Alternatives for Measurements in Natural Streams, Proceedings Hydraulic Measurements & Experimental Methods, ASCE-IAHR Joint Conference, Estes Park, CO (CD-ROM).
  3. Costa, J. E., Spicer, K. R., Cheng, R. T., Peter, H. F., Melcher, N. B., Michael Thurman, E., 2000, Measuring stream discharge by noncontact methods: A proof of concept experiment, Geophysical. Research Letter, 27(4), 553-556. https://doi.org/10.1029/1999GL006087
  4. Hauet, A., Kruger, A., Krajewski, W. F., Bradley, A., Muste, M., Creutin, J. D., Wilson, M., 2008, Experimental System for Real-Time Discharge Estimation Using an Image-Based Method, Journal of Hydrology, 13(2), 105-110. https://doi.org/10.1061/(ASCE)1084-0699(2008)13:2(105)
  5. Jeju Development Institute, 2009, A base research for hydrological and water quality characteristics in Jeju region for utilizing river runoff, Policy Research No. 2009-11, 3-4.
  6. Kim, S., Yu, K., Yoon, B., 2011, Real-time Discharge Measurement of the River Using Fixed-type Surface Image Velocimetry, Journal of Korea Water Resource Association, 44(5), 377-388. https://doi.org/10.3741/JKWRA.2011.44.5.377
  7. Kim, Y., Lee, H., 2011, Improvement of Microwave Water Surface Current Meter and its Commercialization, Conference proceedings of Korea Water Resource Association, 85-85.
  8. Le Coz, J., Hauet, A., Pierrefeu, G., Dramais, G., Camenen, B., 2010, Performance of image-basedvelocimetry (LSPIV) applied to flash-flood discharge measurements in Mediterranean rivers, Journal of Hydrology, 394(1-2), 42-52. https://doi.org/10.1016/j.jhydrol.2010.05.049
  9. Lee J. S., Julien, P. Y., 2006, Electromagnetic Wave Surface Velocimetry, Journal of Hydraulic Engineering, 132(2), 146-153. https://doi.org/10.1061/(ASCE)0733-9429(2006)132:2(146)
  10. Muste, M., Kim, D., Merwade, V., 2012, Modern Digital Instruments and Techniques for Hydrodynamic and Morphologic Characterization of Streams, Chapter 24 in Gravel Bed Rivers: Processes, Tools, Environments, edited by Ashmore P., Bergeron N., Biron P., Buffin-Belanger T., Church M., Rennie C. Roy A.M., Wiley, New York, NY.
  11. Mutronics, 2010, Electromagnetic Wave Surface Velocimetry for normal and low flow, patent No. 10-2010-89895.
  12. Ott, 2000, Radarsensor for contact free measurement of surfacewave level, Kalesto.
  13. Roh, Y., Yoon, B., Yu, K., 2005, Estimation of Mean Velocity from Surface Velocity, Journal of Korea Water Resource Association, 38(11), 917-925. https://doi.org/10.3741/JKWRA.2005.38.11.917
  14. SonTek, 2010, RiverSurvyor M9/S5 Brochure.
  15. Yang, S., Kim, D., Yu, K., Kang, M., Jung, W., Lee, J., Kim, Y., You, H., 2013, Comparison of Flood Discharge and Velocity Measurements in a Mountain Stream Using Electromagnetic Wave and Surface Image, Journal of the Environmental Sciences, 21(6), 739-747. https://doi.org/10.5322/JES.2012.21.6.739
  16. Yang, S., Kim, D., Jung, W., Yu, K., 2011, Analysis and Comparison of Stream Discharge Measurements in Jeju Island Using Various Recent Monitoring Techniques, Journal of the Environmental Sciences, 20(6), 738-788. https://doi.org/10.5322/JES.2011.20.6.783

Cited by

  1. Enhancement Technique of Discharge Measurement Accuracy Using Kalesto Based on Index Velocity Method in Mountain Stream, Jeju Island vol.24, pp.4, 2015, https://doi.org/10.5322/JESI.2015.24.4.371
  2. A Proposal of Unit Hydrograph Using Statistical Analysis in Oedo Stream, Jeju vol.24, pp.4, 2015, https://doi.org/10.5322/JESI.2015.24.4.393
  3. Micro Radar Surface Velocimetry for Hydrologic Signal Processing Using a Bandpass Filtering Approach vol.8, pp.6, 2016, https://doi.org/10.3390/w8060262