• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1172-1175
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• 2006

설계홍수량의 산정에 있어 일반적으로 유역의 강우와 수위자료, 유출량 자료를 이용하여 강우-유출모형을 이용하여 산정하는 방법을 사용한다. 설계홍수량을 산정하는 데 있어 수문자료의 부족으로 인하여 유역에 대한 대표단위도의 결정이 어려워 유역에 대한 지형특성 자료들을 이용하여 추정된 변수들을 이용하여 모형에 적용시켜 산정하고 있다. 모형을 이용하여 설계홍수량의 산정을 하는 것에 있어 각각의 모형의 입력변수들이 지형인자로 인해 산정되는것이나 기왕에 산정된 설계홍수량 자료들이 근본적인 자료인 유역의 특성인자와 어떠한 관계를 가지며 미계측 유역이나 하천정비기본계획이 수립되지 않은 유역에 있어 설계홍수량을 추정하는 데 있어 상당한 어려움이 있는 것이 현실이다. 본 연구에서는 설계홍수량을 추정하는 데 있어 기왕에 하천정비 기본계획에 의해 산정된 설계홍수량과 지형인자들이 어떤 상관성을 가지고 있는 가에 대하여 분석하여 지형특성자료와 확률강우량 자료를 이용한 설계홍수량 추정방안에 대하여 연구하였다.

• 대기
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• 제20권3호
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• pp.343-353
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• 2010

A regional wind network with complex surface conditions must be designed with sufficient space and time resolution to resolve the local circulations. In this study, the spatial variations of the wind field observed in the Seoul and Jeju regional networks were evaluated in terms of annual, seasons, and months to assess the spatial homogeneity of wind fields within the regional networks. The coherency of the wind field as a function of separation distance between stations indicated that significant coherency was sometimes not captured by the network, as inferred by low correlations between adjacent stations. A meso-velocity scale was defined in terms of the spatial variability of the wind within the network. This problem is predictably most significant with weak winds, dull prevailing wind, clear skies and significant topography. The relatively small correlations between stations imply that the wind at a given point cannot be estimated by interpolating winds from the nearest stations. For the Seoul and Jeju regional network, the meso-velocity scale has typically a same order of magnitude as the speed of the network averaged wind, revealing the large spatial variability of the Jeju network station imply topography and weather. Significant scatter in the relationship between spatial variability of the wind field and the wind speed is thought to be related to thermally-generated flows. The magnitude of the mesovelocity scale was significantly different along separation distance between stations, wind speed, intensity of prevailing wind, clear and cloudy conditions, topography. Resultant wind vectors indicate much different flow patterns along condition of contributing factors. As a result, the careful considerations on contributing factors such as prevailing wind in season, weather, and complex surface conditions with topography and land/sea contrast are required to assess the spatial variations of wind field on a regional network. The results in the spatial variation from the mesovelocity scale are useful to represent the characteristics of regional wind speed including lower surface conditions over the grid scale of large scale atmospheric model.

• 한국측량학회지
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• 제24권2호
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• pp.159-165
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• 2006

본 논문에서는 위성고도계자료를 이용하여 개발된 평균해면모델인 CLS_SHOM과 지구중력장 모델인 EGM96으로부터 평균해면고와 지오이드고를 계산하여 해면지형을 계산하고, 이를 이용하여 지형류의 흐름을 추정하였다 지형류의 추정을 통하여 해양의 물리학적인 특성을 연구할 수 있기 때문에 외국에서는 많은 연구가 수행되어 왔으나 우리나라의 경우에는 연구가 이루어지지 않은 상태이다. 본 연구에서는 지형류에 대한 기초연구로서 동해에서의 지형류 흐름특성을 분석하여 제시하였다. 연구결과 동해지역에 대한 해면지형의 평균은 약 37cm로 계산되었고, 지형류 속도는 평균 -0.028m/sec로 계산되었다. 지형류의 흐름은 태평양 해수가 대한해협을 통과하면서 속도가 증가한 후에 일본열도의 외측단을 따라서 동북동 방향으로 거의 일정한 속도로 흐르다가 좁은 Tsugaru 해협과 Soya 해협을 통하여 유출되며, 한반도의 동해안을 따라서 북쪽으로 흐르다가 Soya해협과 북동북으로 향하여 Okhotsk해로 유출되는 것으로 나타났다.

• Ecology and Resilient Infrastructure
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• 제1권2호
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• pp.68-81
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• 2014

본 연구에서는 2차원 흐름/유사이동 모형에 식생생장모형을 추가하여 하도의 식생 활착 및 성장에 의한 지형변화 과정과 특성을 수치모의 하였다. 교호사주가 발달하는 조건에서 식생 이입 및 활착은 사주의 이동을 감소시켰다. 식생면적 및 하폭의 변화는 저유량 지속시간보다 상류유량 변화에 더 크게 영향을 받았다. 상류유량이 감소하면 식생면적은 증가하고 하도폭은 감소하였다. 망상하도가 발달하는 조건에서 하도내 식생 이입 및 활착은 지형변화 특성에 크게 영향을 미쳤다. 망도하도에서 식생은 망상의 수를 감소시키고 결국 상류유량이 크게 감소하면 하도지형을 망상하도에서 단일수로로 변화시켰다. 식생면적은 상류유량이 증가함에 따라 감소하였다. 하도폭은 식생 도입 후 급격히 줄어들었고 상류유량 감소와 함께 감소하였다. 수치모의를 이용하여 홍수량 감소가 하도 내의 식생 이입 및 활착을 가속시키고 이로 인해 하도변화 특성에 미치는 영향을 정성적으로 확인할 수 있음을 보였다.

• 한국지구과학회지
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• 제36권6호
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• pp.533-542
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• 2015

고창 해빈은 황해의 동편, 한국 서남해 연안에 위치하며, 북쪽에서 남쪽 방향으로 동호리, 광승리, 명사십리 해빈으로 구성된다. 고창 해빈은 대조차, 개방형, 직선형 해안, 모래 저질의 특징을 보인다. 본 연구는 고창 해빈에서 표층 지형 변화와 퇴적물 집적률의 연평균과 계절 특성을 연구하였다. 2014년 겨울(2월), 봄(5월), 여름(8월), 가을(11월)과 2015년 겨울(2월)의 5계절 동안, 3개 측선을 따라 총 315개 지점에서 지형 고도를 측정하였다. 해안선에 수직인 각 측선은 30 m 간격의 21 지점으로 구성된다. 고창 해빈의 2014년 연평균 집적률은 -0.081 m/yr로 침식이 우세하였다. 지역별 연평균 집적률은 동호리 해빈 -0.091 m/yr, 광승리 해빈 -0.051 m/yr, 명사십리 해빈 -0.10 m/yr로 나타났다.

• Ocean and Polar Research
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• 제28권3호
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• pp.293-303
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• 2006

The topography of the sea floor and textural characteristics of surface sediments are documented in areas off sectors 1,2, and 4 of the Saemangeum dyke and inside the dyke. These were investigated during the years 2002 to 2005, when the dyke construction almost came to an end, and were compared with natural topographic analogs before the dyke construction from the maritime maps of 1982 and 1994. Along and across the dyke are a number of erosional troughs formed by intensified currents during the dyke construction. The sea floor off sector 4 has undergone gradual accumulation of sands moving from the north by currents varying in direction from normal to parallel to the dyke. This is in a strong contrast with a slight erosional environment prevailing over the sea floor before dyke construction. off sectors 1 and 2, a topography with an alterative pattern of erosional troughs and sand shoals develops normal to the dyke. Eroded materials from the troughs seem to have added to the sand shoals. As a result, the troughs, former natural tidal channels, have become increasingly deeper, whereas the sand shoals have become somewhat shallower. The sea floor inside the dyke has also been remarkably shallower with expanding tidal flats due to trapping by the dyke of continuous sediment input from the Dongjin and Mangyeong rivers. Sands, all of which are considered to have originated originally from the two rivers, dominate the entire Saemangeum area.

• 한국토양비료학회지
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• 제48권3호
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• pp.189-193
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• 2015

Bad drainage problems from paddy fields adjacent to roads are caused by higher constructed roads which change topography of paddy fields to concave topography and artificial pan to prevent road erosion when road constructions are occurred. This study investigated effects of topography changes on soils by road constructions. Soil samples were investigated by physico-chemical analyses and micromorphology analyses from representative soil profile of Sachon series and soil samples. The characteristics of Sachon series that were adjacent to roads were fewer redoximorphic features (RMF) and increase in grey layers than the original Sachon series. The characteristics of Yecheon Series were shown from Jeollanamdo - Suncheon > Chungchungnamdo - Cheonan > Gangwondo - Wonju. Mosaic speckles were shown from micromorphological analyses because of repeat of shrink and expansion by wetting and drying. The location of graying in soil clods were found from coarse stone blocks to fine stone blocks and color changes of composed particles were also found.

• Wind and Structures
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• 제30권6호
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• pp.547-558
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• 2020

With the development of economy and construction technology, more and more bridges are built in complex mountainous areas. Accurate assessment of wind parameters is important in bridge construction at complex terrain. In order to investigate the wind characteristics in the high-altitude difference area, a complex mountain terrain model with the scale of 1:2000 was built. By using the method of wind tunnel tests, the study of wind characteristics including mean wind characteristics and turbulence characteristics was carried out. The results show: The wind direction is affected significant by the topography, the dominant wind direction is usually parallel to the river. Due to the sheltering effect of the mountain near the bridge, the wind speed and wind attack angle along the bridge are both uneven which is different from that at flat terrain. In addition, different from flat terrain, the wind attack angle is mostly negative. The wind profiles obey exponential law and logarithmic law. And the fitting coefficient is consistent with the code which means that it is feasible to use the method of wind tunnel test to simulate complex terrain. As for turbulence characteristics, the turbulence intensity is also related to the topography. Increases sheltering effect of mountain increases the degree of breaking up the large-scale vortices, thereby increasing the turbulence intensity. Also, the value of turbulence intensity ratio is different from the recommended values in the code. The conclusions of this study can provide basis for further wind resistance design of the bridge.

• 한국의류학회지
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• 제15권1호
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• pp.38-47
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• 1991

The purpose of this study was to investigate the effect of physical properties and grain line of fabrics on the drape properties of the flare skirt. Horizontal section overlap map was obtained by three dimensional Moire Topography, It was concluded drapability of the skirt obtained by the map can be used to determine the ease of the skirt. Grain line such as bias and lengthwise direction showed the difference of quality of the drape at the hem line; skirt made by bias direction showed evenly distributed flare and effective for the aesthetic point view. No difference was observed between cotton and polyester fabrics probably due to the similar characteristics of the fabrics.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2006년도 춘계학술발표회 논문집
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• pp.305-309
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• 2006

SAR (Synthetic Aperture Radar) technology, which is not influenced by cloud cover because of using electromagnetic wave of long wavelength, has an advantage in mapping the earth. NASA, recognizing these strong points of SAR, launched SRTM (Shuttle Radar Topography klission), and acquired the topographic information of the earth. SRTM and NED (National Elevation Data) of USGS were used for the research and vegetation height map was produced through differentiating the two data. Correlation between SRTM-NED and planting year was analyzed to see the relationship. Strong correlation was detected and it shows the feasibility of estimating timber age and eventually creating timber age map from SRTM-NED. Additional analyses were conducted to check if the linearity is influenced by regional characteristics and forest uniformity. As results, the correlation between SRTM-NED and timber age is influenced by roughness of the terrain. Overall, this paper shows that timber age estimation using SRTM and NED can be sufficiently practical.