• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.1 s.20
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• pp.83-95
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• 2006

This study aims to analysis of suspended-load concentration in related to those data by measuring vertical sediments distribution with rainfall using the ASM (Argus Surface Meter)- IV at the channel reach of a upstream and a downstream in small river. The watershed, small river basin where had taken for experimental study was selected, which is a drainage area lied at Walha in Yunkee-Gun, Chungnam Province. Measured data of suspended-load concentration consists of two groups with 2,145 data during 1hr 11min 30sec and 1,216 data during 40min 32sec for measuring time of 2 second in the study reaches at river, respectively. In order to analyze of the vertical concentration distribution, using the data sets are selected the measuring time 16 sets one of these data by random in the study reaches. As a results, the Rouse number of a measured and a calculated value show that a rang of $0.00129{\sim}0.02394$, averaged value of 0.01129 md, a rang of $0.00118{\sim}0.00822$, averaged value of 0.00436 in upstream reaches, and also a rang of $0.065115{\sim}0.065295$, averaged value of 0.06521, and a rang of $0.057315{\sim}0.059109$, averaged value of 0.05795 in downstream reaches, respectively. These difference show that measured Rouse number compared with downstream reach errors of less than in upstream reach, but between measured and calculated of the Rouse number compared with downstream reach errors of more than in upstream reach, respectively. It seems to will be included one of the occurrence errors of variable estimations when Rouse number of calculated value to be made computed by the fall velocity with a high temperature of water using equation of empirical kinematic viscosity was derived in this study.

• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.581-592
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• 2000

Turbulence structure and suspended sediment transport capacity in vegetated open-channel flows are investigated numerically in the present paper. The $\textsc{k}-\;\varepsilon$ model is employed for the turbulence closure. Mean velocity and turbulence characteristics including turbulence intensity, Reynolds stress, and production and dissipation of turbulence kinetic energy are evaluated and compared with measurement data available in the literature. The numerical results show that mean velocity is diminished due to the drag provided by vegetation, which results in the reduction of turbulence intensity and Reynolds stress. For submerged vegetation, the shear at the top of vegetation dominates turbulence production, and the turbulence production within vegetation is characterized by wakes. For emergent condition, it is observed that the turbulence generation is dominated by wakes within vegetation. In general, simulated profiles compares favorably to measured data. Computed values of eddy viscosity are used to solve the conservation equation for suspended sediment, yielding sediment concentration more uniform over the depth compared with the one in the plain channel. The simulation reveals that the suspended load decreases as the vegetation density increases and the suspended load increases as the particle diameter decreases for the same vegetation density.