• 제목/요약/키워드: river capture

검색결과 35건 처리시간 0.02초

비등방성을 고려한 사행하천의 유속 공간보간기법 개발 (Development of an anisotropic spatial interpolation method for velocity in meandering river channel)

  • 유호준;김동수
    • 한국수자원학회논문집
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    • 제50권7호
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    • pp.455-465
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    • 2017
  • 2차원 유속장(flow field)은 하천흐름의 특성을 이해하기 위한 중요한 수리학적 자료 중 하나로서, 수공구조물 위치선정 및 설계, 하천에서의 이송-확산 예측, 하천의 수리학적 거동을 예측하기 위한 중요한 기본 자료로 사용된다. 지금까지 이러한 하천흐름 특성을 예측하기 위해 제한적인 현장조건과 적절한 계측방법, 계측기기의 기술적 한계로 인해 현장실험 보다는 다양한 수치모형을 이용하여 왔다. 하지만 최근에는 계측기기의 발달로 과거보다 정확하고 정밀한 현장계측이 가능하여 졌으며, 현장 계측자료의 질적이고 양적인 수요를 만족시키고 있다. 대표적으로 초음파도플러유속계(ADCPs; Acoustic Doppler Current Profilers)는 유량을 정확하게 측정하는 것으로 유명하며, 2차원 뿐만 아니라 3차원 유속장 등 자세한 유속자료를 제공한다. 하지만 이러한 측정 능력에도 불구하고, ADCP를 활용한 유속 측정은 주로 횡단면 측정을 기본으로 수행하기 때문에, 수치모형의 결과와 같이 높은 밀도의 유속장을 얻기 위해서 공간보간기법이 활용되고 있다. 하지만 만곡이 존재하는 자연하천은 하도형상에 따라 유속이 지속적으로 변화하기 때문에 일반적인 공간보간기법을 적용하기 어렵다. 즉, 자연하천의 만곡에 따른 비등방성을 고려하지 않는다면, 역거리가중법(IDW)과 크리깅(Kriging)과 같은 일반적인 공간보간기법으로는 잘못된 결과를 초래할 수 있다. 본 연구에서는 이러한 문제점을 해결하고자 만곡이 존재하는 사행하천을 대상으로 방향성을 고려하기 위한 곡선좌표계와 비등방성을 고려하기 위한 비등방적 참조범위를 적용한 공간보간기법을 개발하였다. 본 연구에서 제시한 기법을 한국건설기술연구원 하천실험센터에 존재하는 3개의 사행수로가 포함된 실규모의 실험수로를 대상으로 적용한 결과, 평균제곱근오차와 상관계수는 기존의 공간보간기법과 비교하여 각각 41.5% 감소, 40.0%가 증가하여 정확성과 상관성이 개선되었다.

한국의 지역개발과 댐건설 (Regional Development And Dam Construction in Korea)

  • 안경모
    • 물과 미래
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    • 제9권1호
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    • pp.38-42
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    • 1976
  • Because of differences in thoughts and ideology, our country, Korea has been deprived of national unity for some thirty years of time and tide. To achieve peaceful unification, the cultivation of national strength is of paramount importance. This national strength is also essential if Korea is to take rightful place in the international societies and to have the confidence of these societies. However, national strength can never be achieved in a short time. The fundamental elements in economic development that are directly conducive to the cultivation of national strength can be said to lie in -a stable political system, -exertion of powerful leadership, -cultivation of a spirit of diligence, self-help and cooperation, -modernization of human brain power, and -establishment of a scientific and well planned economic policy and strong enforcement of this policy. Our country, Korea, has attained brilliant economic development in the past 15 years under the strong leadership of president Park Chung Hee. However, there are still many problems to be solved. A few of them are: -housing and home problems, -increasing demand for employment, -increasing demand for staple food and -the need to improve international balance of payment. Solution of the above mentioned problems requires step by step scientific development of each sector and region of our contry. As a spearhead project in regional development, the Saemaul Campaign or new village movement can be cited. The campaign is now spreading throughout the country like a grass fire. However, such campaigns need considerable encouragement and support and the means for the desired development must be provided if the regional and sectoral development program is to sucdceed. The construction of large multipurpose dams in major river basin plays significant role in all aspects of national, regional and sectoral development. It ensures that the water resource, for which there is no substitute, is retained and utilized for irrigation of agricultural areas, production of power for industry, provision of water for domestic and industrial uses and control of river water. Water is the very essence of life and we must conserve and utilize what we have for the betterment of our peoples and their heir. The regional and social impact of construction of a large dam is enormous. It is intended to, and does, dras tically improve the "without-project" socio-economic conditions. A good example of this is the Soyanggang multipurpose dam. This project will significantly contribute to our national strength by utilizing the stored water for the benefit of human life and relief of flood and drought damages. Annual average precipitation in Korea is 1160mm, a comparatively abundant amount. The catchment areas of the Han River, Keum River, and Youngsan River are $62,755\textrm{km}^2$, accounting for 64% of the national total. Approximately 62% of the national population inhabits in this area, and 67% of the national gross product comes from the area. The annual population growth rate of the country is currently estimated at 1.7%, and every year the population growth in urban area increases at a rising rate. The population of Seoul, Pusan, and Taegu, the three major cities in Korea, is equal to one third of our national total. According to the census conducted on October 1, 1975, the population in the urban areas has increased by 384,000, whereas that in rural areas has decreased by 59,000,000 in the past five years. The composition of population between urban and rural areas varied from 41%~59% in 1959 to 48%~52% in 1975. To mitigate this treand towards concentration of population in urban areas, employment opportunities must be provided in regional and rural areas. However, heavy and chemical industries, which mitigate production and employment problems at the same time, must have abundant water and energy. Also increase in staple food production cannot be attained without water. At this point in time, when water demand is rapidly growing, it is essential for the country to provide as much a reservoir capacity as possible to capture the monsoon rainfall, which concentarated in the rainy seaon from June to Septesmber, and conserve the water for year round use. The floods, which at one time we called "the devil" have now become a source of immense benefit to Korea. Let me explain the topographic condition in Korea. In northern and eastern areas we have high mountains and rugged country. Our rivers originate in these mountains and flow in a general southerly or westerly direction throught ancient plains. These plains were formed by progressive deposition of sediments from the mountains and provide our country with large areas of fertile land, emminently suited to settlement and irrigated agricultural development. It is, therefore, quite natural that these areas should become the polar point for our regional development program. Hower, we are fortunate in that we have an additional area or areas, which can be used for agricultural production and settlement of our peoples, particularly those peoples who may be displaced by the formation of our reservoirs. I am speaking of the tidelands along the western and southern coasts. The other day the Ministry of Agriculture and Fishery informed the public of a tideland reclamation of which 400,000 hectares will be used for growing rice as part of our national food self-sufficiency programme. Now, again, we arrive at the need for water, as without it we cannot realize this ambitious programme. And again we need those dams to provide it. As I mentioned before, dams not only provide us with essential water for agriculture, domestic and industrial use, but provide us with electrical energy, as it is generally extremely economical to use the water being release for the former purposes to drive turbines and generators. At the present time we have 13 hydro-electric power plants with an installed capacity of 711,000 kilowatts equal to 16% of our national total. There are about 110 potential dams ites in the country, which could yield about 2,300,000 kilowatts of hydro-electric power. There are about 54 sites suitable for pumped storage which could produce a further 38,600,000 kilowatts of power. All available if we carefully develop our water resources. To summarize, water resource development is essential to the regional development program and the welfare of our people, it must proceed hand-in-hand with other aspects of regional development such as land impovement, high way extension, development of our forests, erosion control, and develop ment of heavy and chemical industries. Through the successful implementation of such an integrated regional development program, we can look forward to a period of national strength, and due recognition of our country by the worlds societies.

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Headspace - GC/ECD를 이용한 수중의 미량 요오드계 트리할로메탄류 분석 (Analysis of Trace Levels of Lodinated Trihalomethanes in Water Using Headspace - GC/ECD)

  • 손희종;송미정;김경아;염훈식;최진택
    • 대한환경공학회지
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    • 제36권1호
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    • pp.35-41
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    • 2014
  • 소독부산물의 일종인 트리할로메탄류(THMs)는 정수처리 공정에서 소독제로 사용되는 염소와 수중에 잔존하는 유기물질이 반응하여 생성된다. 일반적으로 염소계 및 브롬계 THMs는 일반적인 수돗물에서 검출되기 때문에 잘 알려져 있으나, 요오드계 THMs (I-THMs)의 경우는 수중에 요오드 이온이 존재할 때 생성된다. I-THMs는 약품취를 유발하며, 또한 염소계나 브롬계 THMs에 비해 인체독성이 더 강한 것으로 알려져 있다. 현재 I-THMs 분석을 위한 공인된 분석법은 없는 실정이다. 10종의 THMs 분석을 위해 headspace 전처리장치와 GC/ECD를 이용하여 최적화된 분석법을 개발하였으며, 개발된 분석법에 의한 검출한계(LOD)와 정량한계(LOQ)는 각각 12 ng/L~56 ng/L 및 38 ng/L~178 ng/L로 나타났다. 강물, 해수 및 하수처리장 최종방류수의 matrix 영향을 평가하였으며, 본 연구에서 개발된 분석법은 별도의 전처리 과정이 필요치 않아 간편하고 빠르며 자동화된 방법으로 수중에 미량으로 함유된 I-THMs 분석에 적합한 것으로 나타났다.

3차원 수리·수질 모델을 이용한 대청호 유기탄소 순환 및 물질수지 해석 (Analysis of Organic Carbon Cycle and Mass Balance in Daecheong Reservoir using Three-dimensional Hydrodynamic and Water Quality Model)

  • 안인경;박형석;정세웅;류인구;최정규;김지원
    • 한국물환경학회지
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    • 제36권4호
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    • pp.284-299
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    • 2020
  • Dam reservoirs play a particularly crucial role in processing the allochthonous and the autochthonous dissolved (DOC) and the particulate (POC) organic carbon and in the budget of global carbon cycle. However, the complex physical and biogeochemical processes make it difficult to capture the temporal and spatial dynamics of the DOC and the POC in reservoirs. The purpose of this study was to simulate the dynamics of the DOC and the POC in Daecheong Reservoir using the 3-D hydrodynamics and water quality model (AEM3D), and to quantify the mass balance through the source and sink fluxes analysis. The AEM3D model was calibrated using field data collected in 2017 and showed reasonable performance in the water temperature and the water quality simulations. The results showed that the allochthonous and autochthonous proportions of the annual total organic carbon (TOC) loads in the reservoir were 55.5% and 44.5%, respectively. In season, the allochthonous loading was the highest (72.7%) in summer, while in autumn, the autochthonous loading was the majority (77.1%) because of the basal metabolism of the phytoplankton. The amount of the DOC discharged to downstream of the dam was similar to the allochthonous load into the reservoir. However, the POC was removed by approximately 96.6% in the reservoir mainly by the sedimentation. The POC sedimentation flux was 36.21 g-C/㎡/yr. In terms of space, the contribution rate of the autochthonous organic carbon loading was high in order of the riverine zone, the transitional zone, and the lacustrine zone. The results of the study provide important information on the TOC management in the watersheds with extensive stagnant water, such as dam reservoirs and weir pools.

담수산 어류 꺽지 (Coreoperca herzi)의 자원 평가 및 관리 방안 연구: 섬진강 중.상류 수계에서 꺽지의 자원량 및 잠재생산량 추정 (2) (Stock Assessment and Management Implications of the Korean aucha perch (Coreoperca herzi) in Freshwater: (2) Estimation of Potential Yield Assessment and Stock of Coreoperca herzi in the Mid-Upper System of the Seomjin River)

  • 장성현;류희성;이정호
    • 생태와환경
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    • 제44권2호
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    • pp.172-177
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    • 2011
  • 본 연구는 최적화된 자원량을 기반으로 최대 생산성을 얻을 수 있는 잠재생산량 추정을 통한 어족자원(꺽지)의 효율적 관리방안을 모색하고자 하였다. 이를 위해 섬진강 중 상류 수계에서 2008년 8월부터 2009년 4월까지 계절별로 총 4회 조사를 실시하였다. 자원량 추정은 소해면 적법(Swept Area method)을 이용하였으며, 잠재생산량은 생물학적 허용어획량(Allowable Biological Catch, ABC)에 기초한 어족자원 잠재력 추정시스템을 수정 보완하여 사용하였다. 또한, 꺽지 자원의 효율적인 관리 방안을 검토하기 위해 가입당생산량모델(Beverton and Holt)을 사용하였다. 연구결과, 어획개시연령($t_c$)은 1.464 age로 나타났으며, 이를 체장으로 환산한 결과 7.8 cm(BL)로 확인되었다. 현재 어획강도를 나타내는 순간어획사망계수(F)는 0.061 $year^{-1}$이었으며, 이를 기준으로 한가입당 생산량(Y/R)은 4.124 g로 추정되었다. 어획개시연령($t_c$)과 순간어획사망계수(F)를 기준으로 한 적정어획사망계수($F_{ABC}$)는 0.401 $year^{-1}$로 추정되었는데 이는 현재 꺽지 자원에 대한 어획강도가 매우 낮은 상태임을 시사한다. 꺽지의 연간 자원량은 3,048 kg으로 나타났으며, 현재 어획개시연령과 적정어획사망계수를($F_{ABC}$)를 바탕으로 한 잠재생산량은 861 kg으로 추정되었다. 가입당 생산량 모델을 사용하여 어획개시연령을 3 age로 어획사망계수는 0.643 $year^{-1}$로 가정할 경우, 가입당 생산량은 현재의 4.12 g에서 13.84 g로 약 3.4배 증가될 것으로 예상되었다.