• Journal of Korea Water Resources Association
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• v.40 no.4
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• pp.345-357
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• 2007

• Journal of Environmental Science International
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• v.7 no.4
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• pp.415-424
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• 1998

In the rainfalll-runoff relation, consideration of the spatial movement of storms is very unportant in designing a hydraulic structure or evaluating an environmental influence for land usage. Because of thins reason, this study has suggested the finite element model which consider the spatial movement of a storm and it was applied on a small river basin(Wi stream basin). In the application of the model, the basin was treated as a pivot point and the storms are simulated 10 movement in each directions. As a result, It shows that the storms moving from north to south have higher peak discharge and faster peak time than the storms moving in other directions. So these characteristics have to be considered In the designation of a hydraulic structure or evaluation of an environmental influence.

• Journal of the Korean Geographical Society
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• v.43 no.6
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• pp.858-872
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• 2008

This study examined the meteorological disaster of Jeju Island in Chosun Dynasty based on historical documents, and analyzed how its government and Jeju Islanders responded to this. Recording cases of abnormal weather days of Jeju Island in Chosun Dynasty were most in 17th Century, and then in 18th Century, 16th Century, 15th Century, and 19th Century in order. For the type of meteorological disaster, storm damage was most serious, and then flood disaster, drought disaster, and snow damage were in order. For the region, Jejumok was mostly damaged from storm and flood, and Daejeonghyeon was mostly from drought. Once meteorological disaster occurred, it was a common thing that it continued with famine. The Chosun government relieved Jeju Islanders by moving the grains of mainland into Jeju Island, and for this, installed Galdujin warehouse, Naripo warehouse, and Jemin warehouse. Also, it tried to resolve chronic famine by moving Jeju people into mainland such as Pyeong'an-do. Corresponding to severe weather, the farmers of Jeju Island implemented agricultural methods such as Dapjeon, Baryeong, molding, and wind-breaking; and the seamen conducted unique arts of navigation such as Hwanjeon, and gravel shipment.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.2
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• pp.164-173
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• 2009

MIKE21, a commercial hydrodynamic model, was applied at the Masan Bay to evaluate the model's applicability of simulating the inundation phenomena. A storm surge/inundation model which adopts overflow computation scheme was applied together for comparison. The results of both models show correspondence with not only observed inundation area but also inundation water depth to prove their ability as inundation models. Especially, the accuracy of the MIKE21 model, which just adopts wetting/drying scheme, does not seem to be behind the inundation model. Moreover, an inundation simulation of the virtual MAEMI which was generated at preceding study, was conducted. The inundation area of the virtual MAEMI is similar to that of the real MAEMI, but inundation water depth is deeper than the real MAEMI.

• Journal of Korea Water Resources Association
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• v.37 no.5
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• pp.425-435
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• 2004

Mainly, observed maximum rainfall has been evaluated by point rainfall, but actually it should be considered by means of average areal rainfall. Average areal rainfall is an estimated value computed through DAD(rainfall Depth-Area-Duration) analysis. By using this value, an average and maximum areal rainfall according to area-duration relationship could be computed. In this study, we assume that the whole Korea region is hydrologically homogeneous, and then analyze using the storm-centered DAD(moving-area DAD) method for the past century data. From this analysis, we evaluate the yearly variation of observed maximum areal rainfall through area-duration relationship. And we also construct an IDF(rainfall Intensity-Duration-Frequency) curve by using the annual time series data which is composed of maximum areal rainfall. The characteristics of IDF and observed maximum areal rainfall is also evaluated.

• Journal of Korean Society of Rural Planning
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• v.6 no.2 s.12
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• pp.43-49
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• 2000

Buffer zone selection technique for natural purification of livestock wastewater within a small agricultural watershed was developed using Geographic Information Systems. The technique was applied to $4.12\;km^2$ watershed located in Gosan-myun, Ansung-gun which have 20 livestock farmhouses. As a necessary data for selecting process, feedlot site map, digital Elevation Model (DEM), stream network, soil and land use map were prepared. By using these data, wastewater moving-path tracing program from each feedlot to the stream was developed to get the basic topographic factors; average slope through the paths, distance to the nearest stream and watershed outlet. To identify the vulnerable feedlots for storm event, the grid-based storm runoff model (Kim, 1998; Kim et al., 1998) was adopted. The result helps to narrow down the suitable area of buffer zone, and finally by using subjective but persuasive conditions related to elevation, slope and land use, the suitable buffer zones were selected.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.41-51
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• 2005

Using three-dimensional non-hydrostatical numerical model with one way double nesting technique, atmo­spheric circulation in the mountainous coastal region in summer was investigated from August 13 through 15, 1995. During the day, synoptic westerly wind blows over Mt. Mishrung in the west of a coastal city, Sokcho toward the East Sea, while simultaneously, easterly upslope wind combined with both valley wind from plain (coast) toward mountain and sea-breeze from sea toward inland coast blows toward the top of the mountain. Two different directional wind systems confront each other in the mid of eastern slope of the mountain and the upslope wind goes up to the height over 2 km, becoming an easterly return flow in the upper level over the sea and making sea-breeze front with two kinds of sea-breeze circulations of a small one in the coast and a large one in the open sea. Convective boundary layer is developed with a thickness of about 1km over the ground in the upwind side of the mountain in the west and a thickness of thermal internal boundary layer from the coast along the eastern slope of the mountain is only confined to less than 200 m. On the other hand, after sunset, no prohibition of upslope wind generated during the day and downward wind combined with mountain wind from mountain towardplain and land-breeze from land toward under nocturnal radiative cooling of the ground surfaces should intensify westerly downslope wind, resulting in the formation of wind storm. As the wind storm moving down along the eastern slop causes the development of internal gravity waves with hydraulic jump motion in the coast, bounding up toward the upper level of the coastal sea, atmospheric circulation with both onshore and offshore winds like sea-breeze circulation forms in the coastal sea within 70 km until midnight and after that, westerly wind prevails in the coast and open seas.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.3
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• pp.209-229
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• 2001

Simultaneous field measurements of short-period and long-period waves were made at five stations inside or outside Okkye Harbor, which is located in the east coast of Korea. Based on the measured data, spacial and temporal variations of the long-period wave energy were examined. Three smoothing methods were examined for the spectral estimates: fixed interval averaging method, incremental interval averaging method, and moving averaging method. It was shown that a proper smoothing method should be chosen depending on the period of first resonant mode and the length of data being used. By comparing the results obtained using the long-term data with those obtained using two-day data, we showed that it is necessary to analyze the data of calm seas and storm seas separately. The Helmholtz resonant period in Okkye Harbor was found to be about 9.6 minutes with its relative amplification ratio of 9 to 10, and local amplifications were apparent at the periods of 1.2 to 1.3 minutes and 0.7 minute. During calm seas, both at the harbor entrance and inside the harbor the energy of the waves of 9 minutes or longer period was larger than the infra-gravity wave energy by more than 100 times. However, during storm seas the energy level was very high all over the period band, and local amplification was larger than that during calm seas by more than 100 times, especially inside the harbor, Finally it was shown that the energies of the Helmholtz resonant mode and the infra-gravity waves of 1 to 2 minutes are proportional to the storm wave height.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1179-1183
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• 2010

본 연구에서는 하천유역에 대한 호우의 대표 이동방향을 결정하였다. 대상유역으로는 내성천 유역을 고려하였으며, 101개의 호우사상을 선정하여 각각의 호우사상별로 방향적 특성을 분석하였다. von Mises 분포의 주방향을 이용하여 모든 호우사상의 대표 이동방향을 결정하고, 이를 이용하여 내성천 유역에 대한 호우 대표 이동방향을 결정하였다. 아울러 호우 발생특성별(장마, 태풍, 대류성 강우)로 호우의 방향적 특성을 분류하여 각각의 특성이 구분될 수 있도록 하였다. 적용 결과, 태풍에 의한 호우의 이동방향은 기존 연구결과와 유사하게 주로 북동 방향으로 진행되었으며, 장마와 대류성 강우에 의한 호우가 대표방향 결정에 가장 큰 영향력을 갖는 것으로 나타났다. 아울러 대상유역에 대한 호우의 대표 이동방향은 mode의 특성이 뚜렷하게 한 방향으로 나타나며, 내성천 유역의 경우 대표 호우 이동방향은 59.45도로 결정되었다. 이러한 결과는 한반도에 발생하는 강우의 특성과도 잘 부합하는 것으로 판단된다.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.1-8
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• 2005

In this study, a numerical model combined by a river model and an inland model developed to simulated a flood event. The river model describing an inundation in a river solves the two-dimensional Saint Venant equations with a finite difference method. The inland model based on the ILLUDAS describes the conveyance capacity of a storm sewer system. The combined model is applied to a real situation. The model simulates reasonably the real flood event occurred in a river and inland simultaneously.