• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.2 s.13
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• pp.1-12
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• 2004

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.6
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• pp.375-384
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• 1990

A numerical experiment is made to study the combined effect of differential cooling and bottom topography on the formation of Ulleung Warm Eddy. The Ulleung Warm Eddy appears after the passage around the Ulleung Basin of coastal trapped baroclinic waves generated in the north initial density front to the north, the continental slopes both to the west and south, and the Yamato Rise to the east. It resides therefore always inside the Ulleung Basin, as confirmed by observations.

• Journal of Korea Water Resources Association
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• v.48 no.8
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• pp.673-683
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• 2015

The existing flood protection in rivers has shown the limitation due to the urbanization around rivers and the abnormal climate. Thus, the demand for the constructions of side-weir detention basin are being increased as a part of integrated watershed flood protection plan. It is necessary to estimate the quantitative flood-control effect for including the side-weir detention basin in flood-control measures. For the determination, it is required to reduce the uncertainty of the design factors which can affect the flood-control effect of side-weir detention basin. Among the factors, however, the water level in river always contains uncertainty. Therefore, the design method considering the uncertainty is required. For the reasons, the design method considering uncertainty of the water level in river is suggested in this study with using the length of side-weir which is relatively easy-determinable by designers. Therefore, it is examined how the variation of the length of side-weir can affect the flood-control effect, using HEC-RAS, and then the method to determine the side-weir length considering the uncertainty of the water level in river through results from analyses. Since the uncertainty of the water level in river can be taken into account in the suggested design method, it is evaluated that the design method is more effective to suggest the flood-control effect of the side-weir type detention basin with higher safety side.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.381-388
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• 1999

Several large scale reclamation projects are being underway along the coastal line in Korea. Therefore the large quantity of economical backfill material is necessary to cope with the shortage of dredged soil. In this study, the amount of volume reduction of dredged soil from detention basin was evaluated based on the laboratory tests. The percentage of soil particles in dredged organic soil is about 12.5∼21.9% by weight. The content of heavy metal and environmental effect for dredged soil itself and solidified dredged soil were analysed and the results are far below than those of environmental requirement.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.2
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• pp.221-230
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• 1997

In hydrology analysis, the result of a slope analysis for terrain have an very important effect on water quality and water quantity Recently, a slope analysis tend to use the digital elevation model rater than the traditional map sheet. But a terrain slope analysis by the digital elevation model depends on grid size of the digital elevation model. Hence the effect of a slope analysis by the digital elevation model is a important factor. In this study, therefor, in order to determine a hydrological parameter and a terrain parameter for simulation of the water quality and the hydrological property, we adapted two sample area that are the Nerin stream of the basin of the Soyang lake and a Osip stream of Samchuk, and its individual coverages are $640\;km^2$ and $33\;km^2$. Also to analyze the effect of grid size in the slope of a basin, we apply DEM changing a grid size respectively at intervals of 100 m from 100 m to 1.000m for the Nerin stream basin and at intervals of 10 m from 20 m to 300 m for the Osip stream basin.

• Geophysics and Geophysical Exploration
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• v.15 no.2
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• pp.92-101
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• 2012

Three-dimensional finite-difference simulation in a small-scale half-sphere basin with planar free-surface is performed for an arbitrary shear-dislocation point source. A new scheme to deal with free-surface boundary condition is presented. Then basin parameters are examined to understand main characteristics on ground-motion response in the basin. To analyze the frequency content of ground motion in the basin, spectral amplitudes are compared with each other for four sites inside and outside the basin. Also particle motions for those sites are examined to find which kind of wave plays a dominant role in ground-motion response. The results show that seismic energy is concentrated on a marginal area of the basin far from the source. This focusing effect is mainly due to constructive interference of the direct Swave with basin-edge induced surface waves. Also, ground-motion amplification over the deepest part of the basin is relatively lower than that above shallow basin edge. In the small-scale basin with relatively simple bedrock interface, therefore, the ground-motion amplification may be more related to the source azimuth or direction of the incident waves into the basin rather than depth of it.

• Geomechanics and Engineering
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• v.31 no.2
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• pp.183-195
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• 2022

Under the effects of the near-field earthquakes, the incident angle of the incoming wave could be different. In this study, the influences of some parameters such as incident angle, basin edge, peak ground acceleration level of the bedrock motion as well as different clay types with different consistency on the amplification behavior of the shallow basins are investigated. To attain this goal, the numerical analyses of the basins filled with three different clay types are performed using a fully nonlinear method. The two dimensional models of the basins are subjected to a set of strong ground motions with different peak ground acceleration levels and three different incident angles of 30◦, 45◦ and 90◦ with respect to the horizontal axes. The results show the dominant effect of the obliquely subjected waves at most cases. The higher effect of the 45◦ incident angle on the basin response was concluded. In the other part of this study, the spectral amplification curves of the surface points were compared. It was seen that the maximum spectral amplification of different surface points occurs at different periods. Also, it is affected by the increase in the peak acceleration level of the incoming motions.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.581-587
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• 2014

Sediment basin that is typical facility installed for development business to prevent soil erosion has low removal efficiency and therefore, it causes complaints from the residents and has a bad effect on ecosystem. Thus there is a limit to control soil erosion using the existing design methods of sediment basin, so the purposes of this study is providing suitable design factors for sediment basin with regarding soil characteristic of development areas and analysing sedimentation characteristic by inflow concentration changes. The results, for analyzing the sedimentation characteristic by soil concentrations within approximately 2,000 ~ 20,000 mg/L of initial SS concentration, indicated similar sedimentation trends for same soil in the supernatant regardless of initial concentrations. However, for different soil characteristic (percent finer), there are different results in sedimentation rate and concentrations of the supernatant. Thus it is recommended that sediment basin to prevent soil erosion during construction should be designed based on retention time derived from soil sedimentation experiments regardless of inlet concentration. In addition, installing the soil erosion prevention facility at the back to satisfy effluent water quality should be considered to minimize soil erosion effectively.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.10-20
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• 2005

The change of stream creation has a very sensitive effect on runoff analysis model using the divergence characteristic of stream. Therefore, in this study, the threshold area of stream creation was examined the change characteristic of topographical parameters. The subject basin of the research was the upper basin of the Kumho water gage station which is located in the middle of the Kumho river. The 1:25,000 numerical geography which was constructed $10{\times}10m$ mesh was used. The range of investigation of topographical parameters are number of stream order, length, area, slope, basin relief, sinuosity ratio, drainage density and total stream length etc. It was found from the result of analysis that the threshold value of 1st order stream has a very big effect on topographical parameters of basin. It was found that the threshold area of stream creation was under $0.10km^2$, the parameters showed a big change but showed a very small change over $0.10km^2$.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.911-924
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• 2003

Many researches have been conducting on extracting geometry data and hydrologic parameters by using GIS technique. However, there is no clear standard on those methods yet. This study examines the changing pattern of runoff responses characteristics with applying lumped model on divided watershed. WMS is used in order to divide watershed and calculate hydrologic geometry data and parameters by GIS technique. HEC-1 is adopted as a hydrologic model to establish runoff responses. The basin is divided into small watersheds, which are approximately same size. This research conducted runoff response simulation of Pyoungchang River and Wichon River Basin. Especially, research was focused on what is the most appropriate level as a divined sub-basin, and tested the effect of size of sub-basin for the runoff response simulation. The results showed the size of sub-basin was not an important factor for the simulation results after a certain size. The results of this study can be applied as an appropriate guidance to select optimal simulation size of watershed for the lumped model in a specific watershed.