• Title/Summary/Keyword: Aeolian saltation

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Simultaneous measurement of velocity fields of wind-blown sand and surrounding wind in an atmospheric boundary layer

  • Zhang W.;Wang Y.;Lee S. J.
    • 한국가시화정보학회:학술대회논문집
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    • 2005.12a
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    • pp.11-16
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    • 2005
  • Saltation is the most important mechanism of wind-blown sand transport. Till now the interaction between wind and sand has not been fully understood. In this study the saltation of sand sample taken from Taklimakan desert was tested in a simulated atmospheric boundary layer. The captured particle images containing both the tracers for wind and saltating sand, were separated by a digital phase mask technique. Both PIV and PTV methods were employed to extract the velocity fields of wind and the dispersed sand particles, respectively. The mean streamwise wind velocity field and turbulent statistics with and without sand transportation were compared, revealing the effect of the moving sand on the wind field. This study is helpful to understand the interaction between wind and blown sand (in saltation), and provide reliable experimental data fur evaluating numerical models.

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Grain Size Partitioning Using the Weibull Function and Origin of Fluvial Terrace Deposits (Weibull 함수를 이용한 입도 분리와 하안단구 퇴적층의 기원)

  • Park, Chung-Sun;Cho, Young-Dong;Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.2
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    • pp.15-27
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    • 2019
  • This study tries to reveal transport mechanism and origin of components from fluvial terrace deposits in Danyang and Geum River basins, through grain size partitioning using the Weibull function. Grain size parameters suggest that the samples analyzed in this study can be grouped into the coarse, fine and medium samples. The coarse samples are partitioned into three or four components. More than 65% of the coarse samples consist of components by suspension and saltation by fluvial process, while components by attachment to coarse grains or aggregates and/or by individual grains deposited under non-flow condition are also found in the coarse samples. The fine samples consist of four components and components found in loess deposits in Korea occupy >70%, suggestive of the same transport mechanisms (westerlies and winter monsoon) and common source areas with loess deposits in Korea. However, components by aeolian process from local sources as well as by fluvial process are also found in the fine samples. The medium samples are partitioned into components with similar sizes to the coarse and fine samples, respectively.