• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.6
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• pp.79-85
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• 2006

A simulation was done to analyze the seepage problems due to seawater intrusion through the embedded rock layers on heterogeneous layers of sea-dike. Numerical analysis with SAMTLE(developed by author) was done by taking various relative permeability $ratio(R_r/R_e)$. These results showed, when the sed-dike is newly designed, operated, and maintained considering the safety of sea-dike in seepage problems, these embankment materials are prudently chosen. The permeability of the soil materials, within the range of salinity management in freshwater, is comparatively high, however, the permeability of rock materials for bottom rock layer is low. Therefore, when the relative permeability $ratio(R_r/R_e)$ is bellow 10 it is safety in seepage problems of sea-dike.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.488-496
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• 2000

This study was carried out to investigate the characteristics of longitudinal permeability and hydraulic resistance, and to compare the longitudinal permeability ($K_E$) calculated by the Hagen-Poiseuille's law (Siau, 1971) and the longitudinal permeability (K) measured in sapwood of Acer mono stem. The volume flow rate (Q) in a vessel was $0.80{\times}10^{-4}cm^3/sec$ and the hydraulic resistance ($R_S$) to viscous flow through a vessel was, on average, $1.37{\times}10^{10}dyn{\cdot}sec{\cdot}cm^{-3}{\cdot}cm^{-2}$. The average value of volume flow rate ($Q_N$) through the cross section of sapwood was $0.32cm^3{\cdot}sec^{-1}{\cdot}cm^{-2}$, and the average resistance ($R_{SN}$) was $3.59{\times}10^6dyn{\cdot}sec{\cdot}cm^{-3}{\cdot}cm^{-2}$. The values of K decreased as the diameter of stem increases, which was attributable to variations in the number of vessel per unit area rather than in vessel diameter, and to different resistances in the conducting tissues of each part of the stem. The average value of K measured at breast height was 31% of average value of $K_E$. The $K/K_E$ ratios were 100% in 4 to 6 year-old stems and more than 90% in 7 to 27 year-old stems. The $K/K_E$ ratio decreased as the age of stems increases, and was not more than 20% in near-ground parts of stem.