• 제목/요약/키워드: Complex Terrain

검색결과 334건 처리시간 0.025초

Field measurements of wind characteristics over hilly terrain within surface layer

  • He, Y.C.;Chan, P.W.;Li, Q.S.
    • Wind and Structures
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    • 제19권5호
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    • pp.541-563
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    • 2014
  • This paper investigates the topographic effects on wind characteristics over hilly terrain, based on wind data recorded at a number of meteorological stations in or near complex terrain. The multiply data sources allow a more detailed investigation of the flow field than is normally possible. Vertical profiles of mean and turbulent wind components from a Sodar profiler were presented and then modeled as functions of height and wind speed. The correlations between longitudinal and vertical wind components were discussed. The phenomena of flow separation and generation of vortices were observed. The distance-dependence of the topographic effects on gust factors was revealed subsequently. Furthermore, the canyon effect was identified and discussed based on the observations of wind at a saddle point between two mountain peaks. This study aims to further understanding of the characteristics of surface wind over rugged terrain. The presented results are expected to be useful for structural design, prevention of pollutant dispersion, and validation of CFD (computational fluid dynamics) models or techniques over complex terrains.

산지복잡지형과 생태적 비균질성: 산지경관의 생산성과 수자원/수질에 관한 생태계 서비스 평가 (Complex Terrain and Ecological Heterogeneity (TERRECO): Evaluating Ecosystem Services in Production Versus water Quantity/quality in Mountainous Landscapes)

  • 강신규
    • 한국농림기상학회지
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    • 제12권4호
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    • pp.307-316
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    • 2010
  • 산지복잡지형은 지구표면의 약 20%를 차지하며, 절반 정도의 인류에게 맑은 물을 제공하는 지역이고, 대부분의 주요하천의 발원지로서 국가 혹은 지역 간 사회-경제적 경쟁과 정치적 논란의 대상지역이기도 하다. 산지경관생태계는 우리에게 폭넓은 생태계 생산물과 서비스(맑은 물, 에너지, 식량 및 산림자원 등)를 제공하며, 관광과 휴식활동의 대상으로 크게 부각되고 있다. 이들 지역은 특히 매우 높은 생물다양성과 육상탄소의 주요 저장원이기도 하다. TERRECO사업은 산지복잡지형의 생태계 과정에 대한 이해를 증진하고, 생태계 서비스와 관련한 생태계 기능들을 공간적으로 평가하는 데에 중점을 둔다. 특히 정교한 평가체계를 개발함으로써 산지복잡지형에서의 기후와 토지이용변화에 따른 생태계 서비스 기능의 변화를 정량화할 것이다. 이러한 구도에서 산지복잡지형의 수문학, 수자원, 생산성, 생물다양성, 토양생지화학, 미량가스방출 및 수질 등을 복합적으로 규명하고 있다. TERRECO사업은 총 34개의 세부연구과제로 구성되었으며, 한국산지복잡지형에서의 공동연구를 통해 연구기법의 개발 및 적용을 수행 중에 있다. 세부연구과제들은 산지복잡지형의 경관비균질성에 따른 (1) 물순환과 수자원, (2) 용존유기탄소(DOC), 미세입자상 유기탄소(fPOC), 질소화합물(TN)과 인 함유 물질(TP)의 수송과 수질에 영향을 미치는 탄소와 질소 저장원, (3) 환경적 관심이 높은 미량가스($CO_2$, $N_2O$, $CH_4$)의 포집과 방출, (4) 경관의 생물다양성과 생물다양성에 기인한 생태계 서비스들, 그리고 마지막으로 (5) 농업과 산림 생산성의 차이를 조사하도록 고안하였다. 따라서 TERRECO사업은 한국 산지복잡지형의 생태계 서비스를 조절하는 원리들을 규명하고, 총 34개 세부연구과제의 결과들이 생태계 서비스의 정량적 평가체계를 수립하는 데에 기여하도록 조직화함으로써 새로운 수준의 학제간 정보교환프로그램을 개발하는 데에 기여할 것으로 기대된다.

산악지형에서의 원자력발전소 사고시의 피폭해석 (Analysis of Radiation Exposure from Nuclear Reactor Accident in Complex Terrain)

  • Moon Hee Han;Sung Ki Chae;Moon Hyun Chun
    • Nuclear Engineering and Technology
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    • 제17권3호
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    • pp.216-223
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    • 1985
  • 원자력 발전소로부터 방출되는 기체상 방사성 물질에 의한 환경 영향을 평가함에 있어서 방사성 물질의 대기중에서의 수송과 확산을 기술하는 모델로써 Gaussian plume mode띠 널리 사용되고 있다. Gaussian plume model은 평탄한 지형에 적용하도록 만들어진 모델이므로 대부분의 국토가 복잡한 산악으로 구성된 한극의 경우에 적용하기 위해서는 모델의 수정이 필요하다. 본 논문에서는 2차원적 x-z 평면에서 확산방정식을 해석한 numerical diffusion model과 Gaussian plume model을 비교하여, Gaussian plume mode에서 가장 중요한 변수인 dispersion coefficient를 지형의 높이에 대하여 보정하였다. 보정된 dispersion coefficient 값을 Gaussian plume mode에 적용시켜 계산을 수행한 결과를 보면, 산악지역에서의 방사성 물질의 농도는 평지에서보다 낮게 나타나고 있다.

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복잡 지형에서의 주민선량 계산 (Population Dose Assessment for Radiation Emergency in Complex Terrain)

  • 윤여창;하정우
    • Journal of Radiation Protection and Research
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    • 제12권2호
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    • pp.28-36
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    • 1987
  • 원자력 시설에서 대기중으로 방출되는 방사성 구름에 의한 환경선량계산에는 Gaussian plume model 주로 사용되고 있으나, 바람의 분포나 대기의 흐트러짐이 공간적으로 일정하지 않은 복잡 지형에의 적용에는 문제가 있다. 복잡 지형을 고려한 기류계산에는 MATTEW, WIND04 코드가 그 타당성을 인정받고 있다. 이러한 코드의 원리를 기초로 하여, 질량보존법칙을 만족하는 이류 확산 방정식을 유한차분법으로 계산하고 풍속장을 구하였다. 입자 농도와 피폭선량은 방사성 구름을 입자군으로 근사시키는 PIC model을 이용하여 계산하였으며, 입자의 대기 확산은 Random Walk법을 이용하였다. 계산 결과, 지형에 의한 풍속, 풍향의 변화를 알 수 있었으며, 피폭선량분포를 구할 수 있었다.

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시화지구의 대기오염물질 확산에 관한 전산모사 (Simulation of the Dispersion of Air Pollutants in the Shihwa Area)

  • 송은석;류진복;김병수;이성철;홍민선;장영기
    • 환경영향평가
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    • 제7권1호
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    • pp.35-48
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    • 1998
  • Gaussian type models have limitations on predicting a detailed description of the near flow and pollution leads over complex terrains under neutral atmospheric conditions. Also, most models used recently have lack of ability to include atmospheric reactions. The model based on the numerical solution of the time-averaged Navier-Stokes equations and conservation equations needs to be developed to improve the limitations mentioned above. When the model was applied to the Shihwa area where the tracer experiment had been carried out, the simulation results have a great difference from the experimental results. There are two reasons that make the difference between the results by the model and the experiment. First, the Shihwa area is not a complex terrain. Second, meteorological data is insufficient. Therefore, the model should be applied to predict the dispersion of air pollutants over complex terrain rather than flat terrain in order that the model could be verified because the model was developed for the prediction of the dispersion over a complex terrain.

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복잡지형에서의 Wind Shear Exponent 예측 (Prediction of Wind Shear Exponent in Complex Terrain)

  • 김현기;김병민;김진한;백인수;유능수
    • 한국태양에너지학회 논문집
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    • 제32권2호
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    • pp.87-94
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    • 2012
  • In this study, we found a relationship between wind shear exponent, ${\alpha}$, and a few factors such as the wind speed, $V$, ruggedness index($RIX$), and the Weibull shape parameter, $k$ of sites in complex terrain in Korea. Wind shear exponents in main wind directions were calculated using wind speed data measured for one year from various heights of eleven meteorological masts in Gangwon province. It was found from the analysis that the reciprocal of the wind shear exponent can be expressed by an exponentially decaying function with respect to a multiple of $V$, $RIX$ and $k$. This result is considered useful to be used to characterize wind characteristics of specific sites in complex terrain in Korea with limited information.

연안부근 복잡지형의 대기유동장 수치실험 II -부산광역지역에 대한 국지순환모형의 적용- (A Numerical Experiments on the Atmospheric Circulation over a Complex Terrain around Coastal Area. Part II :)

  • 김유근
    • 한국대기환경학회지
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    • 제16권2호
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    • pp.151-158
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    • 2000
  • Since Pusan metropolitanarea where is composed complex terrain is connected to sea the sea-land breeze circulation and the mountain-valley circulation are apt to form A regional scale circulation system is formed at a region which has complex terrain because of curves of its and affect to the dispersion and advection of air pollutants. LCM Local Circulation Model which a propriety was verified described that sea breeze and valley wind at the daytime and land breeze and mountain wind at the nighttime were well devellped over the Pusan metropolital area. Next for the investigation of accuracy of simulated results an observed value at Kae-Kum and Su-Young on the pusan metropolitan area were compared with it at those points. From the comparison of the temperature and horizontal velocity between the results of LCM and an observed values they have a similar trend of a diurnal variation. For the prediction of dispersion and transportation of air pollutants the wind field should be calculated with high accuracy. A numerical simulation using LCM can provide more accuracy results around Pusan metropolitan area.

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산악 계곡지형에서의 오염확산에 관한 연구(II) :수치해석 (A Study on the Pollutant Dispersion over a Mountain Valley Region (II) : Numerical Simulation)

  • 심우섭;김석철;유성연
    • 설비공학논문집
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    • 제17권11호
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    • pp.1060-1071
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    • 2005
  • Passive gas dispersions over a 1/1000 scale terrain model at Eiffel type wind tunnel were reproduced by numerical simulation. Large eddy simulation was used to treat the sub-grid scale turbulences. The terrain features were represented by millions of point forces densely distributed over the solid surface using the virtual boundary method. The model simulations agreed very well with the experiments in a consistent fashion for all wind directions. The measured profiles of the wind speeds as well as the tracer gas concentrations were nicely simulated by the CFD model at most locations scattered over the model terrain. With scale factor adjusted and the thermal stratification effects incorporated, the CFD model was expected to provide reliable information on pollutant dispersions over the real complex terrains.

선형이론에 의한 복잡지형 내 난류 특성의 예측 (A Prediction of Turbulent Characteristics in a Complex Terrain by Linear Theory)

  • 윤정은;경남호;김성완
    • 한국태양에너지학회 논문집
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    • 제25권1호
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    • pp.79-86
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    • 2005
  • The external conditions for estimating dynamic wind loads of wind turbines, such as the turbulence, the extreme wind, the mean velocity gradients and the flow angles, are simulated over GangWon Wind Energy Test Field placed in one of the most complex terrain in Korea. Reference meteorological data has been gathered at a height of 30m from 2003 to 2004 with a ultrasonic anemometer. The absolute value of the spectral energy are simulated and the verification of this prediction has been carried out with comparing to the experimental data. The most desirable place for constructing new wind turbine are resulted as Point 2 and Point 3 due to the lower value of Turbulence Intensity and the higher value of wind resource relatively.

연안도시지역에서 대기오염의 3차원 수치예측모델링 -(I) 침적현상이 대기질에 미치는 영향예측 (3-D Numerical Prediction Modeling of Air Pollution in Coastal Urban Region -(I) An Effect Prediction for Deposition Phenomenon affecting on Air Quality)

  • 원경미;이화운
    • 한국대기환경학회지
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    • 제15권5호
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    • pp.625-638
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    • 1999
  • Air quality modeling for coastal urban region has been composed of a complex system including meteorological, chemical and physical processes and emission characteristics in complex terrain. In this study, we studied about an effect prediction for deposition phenomenon affecting on air quality in Pusan metopolitan metropolitan city. In air quality modeling including ship sources, a situation considered deposition process habe better result than not considered when compared with observed value. Air pollutants emitted into urban air during the daytime nearly removed through urban atmosphere polluted. Also these phenomena correlated concentration variation connent with sea/land breezes and terrain effect. Therefore we conclude that the concentration was low at daytime when deposition flux is high, and deposition effect on industrial complex and Dongrae region is considerable in particular.

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