• Journal of Korea Water Resources Association
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• v.39 no.7 s.168
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• pp.553-562
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• 2006

The relative contributions of overland-flow and stream-flow to the response process at the basin scale are evaluated in the present study. The moments of GIUH models were applied to the data of the Bocheong watershed in the Geum river basin in Korea in order to discuss the feasibility. The GIUH model derived in this study consists of the stream path and overland region. The characteristic velocities for the flows between two cases mentioned above make a clear distinction as expected and would have more physical meaning than the ones of the model by Rodriguez-Iturbe and Valdes(1979). The path lengths of overland for each stream order are nearly constant, whereas the case of stream is shown to grow larger according to the basin sizes. As a result, the overall basin response process was founded out to be greatly under the influence of the hydrodynamic behavior of overland, and its behavior is suggested to be further researched for catching the broader meanings.

• Journal of Korea Water Resources Association
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• v.42 no.11
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• pp.897-909
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• 2009

The relative contribution of between hillslope-flow and stream-flow by heterogeneity of drainage path are quantitatively assessed in the present study with GIUH model based on grid of GIS. Application watersheds are selected Pyeongchang, Bocheong and Wi river basin of IHP in Korea. The mean and variance of hillslope and stream length are estimated and analyzed in each watershed. And coupling with observation storm events, estimate hillslope and stream characteristic velocity which dynamic parameters of GIUH model. The mean and variance of distribution of travel time (i.e. IUH) calculate using estimated pass lengths and characteristic velocities. And the relative contributions are assessed by heterogeneity of drainage path. As a result, the effect of the variance that determine shape of IUH dominate with hillslope's effect in the small watershed area (within 500 $km^2$). Thus, GIUH in the small watershed area must consider hillslope-flow.

• Journal of the KSME
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• v.22 no.6
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• pp.452-455
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• 1982

본 강연에서는 기계공학의 한 중요한 필수과목인 유체역학 분야에 있어서 실험유체역학 강좌의 개설 필요성을 이야기하고 현재 국내 대학여건을 고려하여 적당한 예산 및 시간배정으로 가능한 예를 들어 이를 설명코자 한다. 유체의 유동현상에 관한 학문인 유체역학은 우리가 살고 있는 대기의 유동, 지표면을 흐르는 강물유동, 해류유동으로 부터 인체의 혈관내의 혈액유동등등 우 리의 일상생활과 밀접한 관련을 맺고 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.307-311
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• 2006

일반적으로 도달시간은 지표면 유출의 흐름상태에 의존하며, 대개 중력흐름으로 가정하여 도달시간을 산정하고 있다. 본 연구에서는 흐름상태를 중력흐름과 표면장력흐름으로 구분하고 각 흐름을 판단할 수 있는 임계치를 추정하였다. 도달시간 산정을 위해 유역경사와 지표면조고의 영향을 고려할 수 있는 무차원수를 도입하였으며, 이 임계치의 범위에 따라 중력흐름과 표면장력흐름을 구분하고 두 조건의 흐름상태에 따른 도달시간 산정식을 각각 개발하였다. 중력흐름에 의한 도달시간 산정식과 표면장력흐름에 의한 도달시간 산정식을 개발하고 검증하기 위하여 기존 외국에서 실험한 자료를 비교 분석하였다. 분석결과를 통하여 이러한 흐름특성을 고려한 도달시간 산정식을 모형에 적용할 경우 유출모형을 통한 유출량산정의 정확도 향상에 기여할 것으로 판단된다.

• Journal of Korea Water Resources Association
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• v.41 no.8
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• pp.797-806
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• 2008

The geometric properties of the drainage structures are analyzed through depicting the drainage network which is composed of the whole drainage paths in the natural basin defined at the specific scale. The theoretical consideration is performed on the general structures of networks organized by ramification process based on Fractal tree and Horton's law. The drainage network is generated via ArcGIS, ordered by Strahler's ordering scheme and investigated with Strahler's order. As a results of the Richardson's method it is shown that there may exist the distinct behavioral characteristics between overland-flow and channel flow and the natural stream networks would be space-filling Fractals. As a result, it is shown that the values estimated by considering the overland-flow on being applied to the field data give the different results from the empirical method applied until now. As expected, therefore the results obtained from this study are sure to be devoted further researches on the channel networks.

• Journal of Korea Water Resources Association
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• v.33 no.S1
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• pp.65-70
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• 2000

• Proceedings of the Korea Water Resources Association Conference
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• 2000.05a
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• pp.65-70
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• 2000

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1057-1062
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• 2009

대부분의 홍수 예측모형은 도달시간 산정에 있어 지표면 흐름을 중력흐름으로 가정한다. 그러나 Woo & Brater(1961)의 실험결과 지표면 흐름의 마찰계수는 바닥정사의 함수인 것으로 나타나며 수심이 매우 얕은 흐름의 경우 조고뿐만 아니라 바닥경사에 의한 영향이 매우 큰 것으로 나타났다. 새로운 무차원수 Y는 바닥경사, 수심, 조고 및 표면장력 등을 고려하는 인자로서 중력흐름과 표면장력흐름의 각 흐름특성을 반영하기 위한 새로운 도달시간 산정식을 개발하였다. 새로운 무차원수 Y는 표면장력과 관계된 후르드수 및 웨버수의 조합으로 조고뿐만 아니라 바닥경사, 수심의 함수로 나타난다. 지표면 흐름의 마찰계수 산정시 비례상수 ${\alpha}$를 새로운 무차원수 Y의 함수로 취하여 Butler(1977)의 실험자료를 분석하였다. 중력흐름의 경우 조고만의 함수로 나타나지만 표면장력흐름은 조고뿐만 아니라 바닥경사의 영향이 매우 중요한 것으로 나타났다. 중력흐름만을 고려하여 도달시간 산정시 관측치보다 작게 산정되는 반면 표면장력흐름으로 고려하여 도달시간 산정시 관측치와 근접하게 산정되었다. 따라서 지표면 유출 흐름은 중력과 함계 표면장력의 영향이 크게 작용하는 것으로 판단된다. 분석결과와 같이 표면장력흐름 특성을 고려한 도달시간 산정식을 모형에 적용할 경우 유출모형을 통한 유출량산정의 정확도 향상에 기여할 것으로 판단된다.

• Journal of the Korean GEO-environmental Society
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• v.5 no.2
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• pp.63-69
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• 2004

During and after the construction of embankment on soft ground, consolidation settlements and lateral displacements develop. But generally it's very difficult to predict the magnitude of lateral deformations and the correct distribution of lateral displacements with depth under the toe of embankment because the consolidation and the shear deformations of soft ground occur simultaneously. This study shows that later displacements of ground surface arise by embankment loading act on soft clay hight water contents in laboratory model testing. The results of model test are observed settlement of embankment, amount of maximum rising and displacement of ground surface with loading velocity. The formula were proposed to predict lateral movement by test series.

• Journal of Korea Water Resources Association
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• v.34 no.1
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• pp.91-103
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• 2001

In this studs, hydraulic routing model has been developed to predict the water level and discharge in each river section with considering the full interaction between surface runoff and river flow. It improved the computation of flood runoff by reflecting the shape of hydrograph that was determined by the geological and flood characteristics, and the excessive computation of the peak discharge was eliminated by considering the effect of infiltration. The Inflow from surface runoff to river flow was applied to the equation of continuity by implementing effectively the flow in a number of river section, and resulted in a numerical stability at the rapid variation of rainfall. Measurements were conducted during heavy rain in the watershed area of Yang-Yang Namdae-Chun. The present model was tested to the field, and the computed results were compared to the observed data. Its applicability was confirmed with its verification.