한국수자원학회논문집 (Journal of Korea Water Resources Association)

  • 제47권12호
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  • Pages.1213-1225
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  • 2014
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  • 2799-8746(pISSN)
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  • 2799-8754(eISSN)
한국수자원학회 (Korea Water Resources Association)
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실내실험에 의한 혼합사로 구성된 하상 표층에서 지형변동에 따른 유사의 분급 특성 분석

Experimental Study on the Sediment Sorting Processes of the Bed Surface by Geomorphic Changes in the Alluvial Channels with Mixed Grain Size

  • 장창래 (한국교통대학교 토목공학과)
  • Jang, Chang-Lae (Department of Civil Engineering, Korea National University of Transportation)
  • 투고 : 2014.09.03
  • 심사 : 2014.11.15
  • 발행 : 2014.12.31
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초록

본 연구에서는 혼합사로 구성된 망상하천에서 사주의 변화와 하상토 분급현상을 실내실험을 통하여 파악하였다. 하상경사가 급한 하도에서 유사 유출량은 시간의 변화에 따라 매우 불규칙하지만, 경사가 완만한 하도에서 유사 유출량은 규칙적이고, 일정한 주기를 나타내었다. 또한 2중 퓨리에 해석을 통하여 지배적인 사주의 특성과 진폭을 분석하였다. 하상고가 상승하면 무차원 하상토 입경은 작아졌지만, 하상고가 저하되면 무차원 하상토 입경은 커졌다. 기층에서 무차원 한계소류력과 표층에서 무차원 한계 소류력의 비가 증가하면, 표층에서 평균입경과 무차원 하상토 중앙입경이 작아졌다. 또한 국부적으로 하상경사가 증가하면서, 유사의 선택적 이동에 의하여 하상토가 분급되고, 평면적으로 입경이 불균일하게 분포하는 분급 특성이 나타났다.

The development of bars and sediment sorting processes in the braided channels with the mixed grain sizes are investigated experimentally in this study. The sediment in the steep slope channels discharges with highly fluctuation. However, it discharges with relatively periodic cycles in the mild slope channels. The characteristics and amplitudes of the dominant bars are examined by double fourier analysis. The dimensionless sediment particle size decreases as the longitudinal bed elevation increases. However, the size increases as the longitudinal bed elevation decreases. As the dimensionless critical tractive force in the surface layer ratio to the force in the subsurface layer increases, the surface geometric mean size of sediments and the dimensionless sediment particle size decrease. This means that coarse matrix is formed with the dimensionless tractive force by the sediment selective sorting.

키워드

참고문헌

  1. Blom, A., and Ribberink, J.S. (2003). "Vertical sorting in bed forms: Flume experiments with a natural and a trimodal sediment mixture." Water Resources Research, Vol. 39, No. 2, 1025, doi:10.1029/2001WR001088, 2003
  2. Gran, K., and Paola, C. (2001). "Riparian vegetation controls on braided stream dynamics." Water Resour. Res., Vol. 37, No. 12, pp. 3275-3283. https://doi.org/10.1029/2000WR000203
  3. Jang, C.-L. (2013). "Experimental analysis of the morphological changes of the vegetated channels." J. Korea Water Resources Association, Vol. 46, No. 9, pp. 911-921. (in Korean) https://doi.org/10.3741/JKWRA.2013.46.9.909
  4. Kleinhans, M.G. (2002). Sorting out sand and gravel sediment transport and deposition in sand-gravel bed rivers, Ph. D. dissertation, Utrecht University, The Netherlands.
  5. Lanzoni, S. (2000). "Experiments on bar formation in a straight flume 2. Graded sediment." Water Resour. Res., Vol. 36, No. 11, pp. 3351-3363. https://doi.org/10.1029/2000WR900161
  6. Lisle, T.E., Ikeda, H., and Iseya, F. (1991). "Formation of stationary alternate bars in a steep channel with mixe-size sediment: a flume experiment." Earth Surf. Processes Landforms, Vol. 16, pp. 463-469. https://doi.org/10.1002/esp.3290160507
  7. Lisle, T.E., Iseya, F., and Ikeda, H. (1993). "Response of a channel with alternate bars to a decrease in supply of mixed-.size bed load: A flume experiment." Water Resour. Res., Vol. 29, No. 11, pp. 3623-3629, doi:10.1029/93WR01673.
  8. Nelson, P.A., Dietrich, W.E., and Venditti, J.G. (2010). "Bed topography and the development of forced bed surface patches." J. Geophys. Res., Vol. 115, F04024, doi:10.1029/2010JF001747.
  9. Paola, C., and Seal, R. (1995). "Grain size patchiness as a cause of selective deposition and downstream fining." Water Resour. Res., Vol. 31, No. 5, pp. 1395-1408, doi:10.1029/94WR02975.
  10. Parker, G. (1990). "Surface-based bedload transport relation for gravel rivers." Journal of Hydraulic Reseach, IAHR, Vol. 28, No. 4, pp. 417-436. https://doi.org/10.1080/00221689009499058
  11. Parker, G., and Klingeman, P.C. (1982). "On why gravel bed streams are paved." Water Resour. Res., Vol. 18, No. 5, pp. 1409-1423, doi:10.1029/WR018i005p01409.
  12. Parker, G., Klingeman, P.C., and McLean, D.L. (1982). "Bedload and size distribution in paved gravel-bed streams." J. Hydraul. Eng., ASCE, Vol. 108, No. HY4, pp. 544-571.
  13. Parker, G. (1990). "Surface-based bedload transport relation for gravel rivers." J. Hydraul. Res., Vol. 28, No. 4, pp. 417-436, doi:10.1080/00221689009499058.
  14. Wilcock, P.R. (1993). "Critical shear stress of natural sediments." J. Hydraul. Eng., ASCE, Vol. 119, pp. 491-505. https://doi.org/10.1061/(ASCE)0733-9429(1993)119:4(491)
  15. Wilcock, P.R., and McArdell, B.W. (1993). "Surface based fractional transport rates: Mobilization thresholds and partial transport of a sand-.gravel sediment." Water Resour. Res., Vol. 29, No. 4, pp. 1297-1312, doi:10.1029/92WR02748.
  16. Wathen, S.J., Ferguson, R.I., Hoey, T.B., and Werritty, A. (1995). "Unequal mobility of gravel and sand in weakly bimodal river sediments." Water Resour. Res., Vol. 31, No. 8, pp. 2087-2096. https://doi.org/10.1029/95WR01229

피인용 문헌

  1. Experimental study on the sediment sorting processes of the bed surface by geomorphic changes in the vegetated channels vol.49, pp.1, 2016, https://doi.org/10.3741/JKWRA.2016.49.1.73