• 제목/요약/키워드: Reservoirs

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팔당호와 청평호 퇴적물에서 영양염류 용출 특성 (Characteristics of Release Rate of Nutrients from Sediment in Lake Paldang and Lake Cheongpyeong)

  • 이규;최명재;박혜경;이장호
    • 한국물환경학회지
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    • 제25권5호
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    • pp.742-749
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    • 2009
  • To examine the characteristics of the nutrient release from the sediments in two reservoirs, Lake Paldang and Lake Cheungpyeung, we analyzed physical and chemical properties of the sediments and calculated the nutrient release rates from the sediments. The particle properties of sediments in Lake Paldang changed from silt to sand after summer rainy season, especially in the water area of the Kyeungan River where the water depth was shallow and the width of river was narrow. The sediments in Lake Cheungpyeung had higher contents of silt and clay than in Lake Paldang, and the particle size was not much different before and after rainfall. The release rates of nutrients in two lakes varied with the kind of nutrients and the season. The release rates of DTN and ${NH_4}^+-N$ in Lake Paldang were faster in spring than autumn. But the Lake Cheungpyeung showed similar values of release rates before and after summer rainy season. ${NO_3}^--N$ and phosphorous were not released from sediments or were absorbed into sediments all the time in two lakes. Compared with other lakes, the sediments of two lakes consisted of bigger particles and had a lower organic matters content than other lake-type reservoirs. Due to the short hydraulic retention time and no stratification throughout the year in Lake Paldang and Lake Cheungpyeung, the release rates of nutrients from sediment in these reservoirs were lower than other lakes and this seems to be a typical characteristic of river-type reservoirs.

전산유체역학(CFD)을 이용한 저수조 내부 유동장 해석 (Analysis of Water Storage Tank Flowfield using Computational Fluid Dynamics (CFD) Simulation)

  • 최연우;한민수;송준혁;왕창근
    • 한국물환경학회지
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    • 제34권2호
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    • pp.173-182
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    • 2018
  • Reservoirs, facilities to store water, are being used in several fields for their ability to hold back a large quantity of water for a long time before the water is actually used. However, at the same time, the reservoirs are considered to have a flaw: the longer they store water, the more the quality of water in these reservoirs deteriorates. Further, when the reservoirs are large, they are more likely to have dead-water regions in out-of-the way spots far from either an in-current or an ex-current canal. This study conducted a Computational Fluid Dynamic (CFD) simulation and tried to figure out the internal flow inside each of the reservoirs with different in-current canals built by the multiple hoe screw nozzle method and the drop in-current method. The drop in-current method is more frequently used. According to the analysis of the internal flow inside each reservoir with the different methods applied, we found that the reservoir with the drop in-current canal would have two rotary currents in the lower region of the reservoir and that the velocity of flow would decrease. For a reservoir with the screw nozzle method, a single rotary current occurred, and inside the reservoir, regardless of height, the current turned out to flow in a regular manner.

Stable carbon isotope signatures of zooplankton in some reservoirs in Korea

  • Lee, Jeayong;Lee, Yunkyoung;Jang, Changwon;Owen, Jeffrey S.;Kim, Jai-Ku;Eum, Jaesung;Jung, Sungmin;Kim, Bomchul
    • Journal of Ecology and Environment
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    • 제36권3호
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    • pp.183-191
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    • 2013
  • Dissolved organic carbon (DOC) concentrations and zooplankton and particulate organic matter (POM) ${\delta}^{13}C$ values were measured in five reservoirs in Korea. Zooplankton ${\delta}^{13}C$ and POM ${\delta}^{13}C$ showed large range from -33‰ to -22‰ and a significant difference among the reservoirs. One eutrophic reservoir, Lake Masan, showed unique characteristics with the highest zooplankton density, the highest ${\delta}^{13}C$, and the highest DOC. Zooplankton ${\delta}^{13}C$ was similar to POM ${\delta}^{13}C$, implying that zooplankton occupies substantial portion of POM or that zooplankton isotopic composition is related to selective grazing and assimilation of food sources from bulk POM. Except Lake Masan zooplankton ${\delta}^{13}C$ values were negatively correlated to DOC concentration in four reservoirs with mostly forest land use. This pattern can be probably attributed to intensive agricultural land use in the watershed of Lake Masan compared to the mostly forest land use in the other watersheds. Understanding the relationship between zooplankton ${\delta}^{13}C$ values and the origin of organic matter associated with watershed characteristics will be valuable to better understand trophic relationships in reservoirs in the summer monsoon region.

전작.원예단지 조성을 위한 새만금 인근 주요 저수지의 수질조사 및 용수이용 가능성 연구 (Investigation of Water Quality and Irrigation Water Use Possibility of Reservoirs Near Saemangeum for Upland and Horticultural Fields)

  • 송재도;손재권;최진규;김영주
    • 한국관개배수논문집
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    • 제14권2호
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    • pp.214-224
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    • 2007
  • This study was carried out to investigate of water quality and irrigation water use possibility of reservoirs near Saemangeum for upland and horticultural fields. Water samples were taken at 6 reservoirs for 5 months from June, 2006 to November, 2006. The water temperature, pH, EC, EC, chlorophyll - a of 6 reservoirs were ranged 8.7-$31.2^circC$, 6.9-9.2, 73.0-637.0$\mu$S/cm, 0.9-443.2mg/$m^3$, respectively. The concentration of DO, BOD, COD, T-N, T-P and SS were ranged 5.7-11.7mg/L, 0.5-8.9mg/L, 2.9-18.0mg/L, 0.07-6.52mg/L, 0.002-0.406mg/L, 0.5-54.0mg/L Also, storage ratio and storage capacity of Mije reservoir, Okgu reservoir, Oknyeo reservoir, Neungje reservoir were decreased between June and April, but those of Oksan reservoir was kept high during irrigation period. Water supply of reservoirs was 4,474,100$m^3$(Oksan), 6,165,900$m^3$(Mije), 13,209,900$m^3$(Okgu), 4,675,600$m^3$(Oknyeo), 7,682,000$m^3$(Neungje), 19,231,000$m^3$(Cheongho) in 2006, respectively. It is resevoirs for upland and horticultural fields that use main irrigation water resources before Saemanguem fresh-water lake development, and use assistance irrigation water resources in emergency after Saemanguem fresh-water lake development. In the meantime, for continuous use of reservoir as irrigation water resource for upland and horticultural fields, we must examine about surplus water capacity, and need investigation about supply possibility of irrigation water, condition of irrigation water, water quality.

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북한강 수계 대규모 탁수사상 발생에 의한 댐 저수지의 탁수 영향 분석 (Analyzing the Effect of an Extreme Turbidity Flow Event on the Dam Reservoirs in North Han River Basin)

  • 박형석;정세웅;정선아
    • 한국물환경학회지
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    • 제33권3호
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    • pp.282-290
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    • 2017
  • A long-term resuspension of small particles, called persistent turbidity, is one of the most important water quality concerns in the dam reservoirs system located in North Han River. Persistent turbidity may incur aesthetic nuisance and harmful effect on the ecosystem health, in addition to elevated water treatment costs for the drinking water supply to the Seoul metropolitan area. These sufferings have been more intensified as the strength and frequency of rainfall events increase by climate change in the basin. This study was to analyze the effect of an extreme turbidity flow event that occurred in 2006 on the serial reservoirs system (Soyang-Uiam-Cheongpyung-Paldang) in North Han River. The CE-QUAL-W2 model was set up and calibrated for the river and reservoirs system using the field data obtained in 2006 and 2007. The results showed that Soyang Reservoir released turbid water, which was classified as the TSS concentration is greater than 25 mg/L, for 334 days with peak TSS of 264.1 mg/L after the extreme flood event (592.7 mm) occurred between July 10 and 18 of 2006. The turbid water departed from Soyang Reservoir reached at the most downstream Paldang Reservoir after about 20 days and sustained for 41 days, which was validated with water treatment plant data. Since the released water from Soyang Reservoir had low water temperature and high TSS, an underflow formed in the downstream reservoirs and vertically mixed at Paldang Reservoir due to dilution by the sufficient inflow from South Han River.

국내 호수에서 Microcystins의 생합성에 관여하는 mcyA 유전자의 염기서열 다양성 분석 (Analysis of Sequence Diversity of mcyA Gene Involved in Microcystin Synthesis in Korean Reservoirs)

  • 오경희;한아원;조영철
    • 미생물학회지
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    • 제46권2호
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    • pp.162-168
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    • 2010
  • 국내에서 분리된 독소생산 Microcystis 속과 조류 대발생 시기에 대청호, 충주호, 용담호, 소양호, 및 의암호에서 채취한 시료에서 조류 독소인 microcystins의 생합성에 관여하는 mcyA 유전자의 염기서열 다양성을 분석하였다. GenBank에 등록된 mcyA 염기서열과 비교한 결과, 국내 호소에서 분리된 Microcystis 속의 mcyA 유전자 염기서열은 매우 낮은 다양성을 나타내었다. 환경 시료 분석 결과, 2-3종류의 clone이 전체의 87-100%를 차지하였으며, Anabaena 속이나 Planktothrix 속의 mcyA 유전자와 유사한 염기서열은 발견되지 않았다. 이러한 결과로 볼 때, 대상 호소에서 microcystins는 주로 Microcystis 속에 의해 생산되며, 독소 생산에 관여하는 mcyA 유전자의 염기서열은 보존되어 있는 것으로 판단된다.

관개취약성 평가모형 및 군집분석을 활용한 용수공급 위험도 평가 (Water Supply Risk Assessment of Agricultural Reservoirs using Irrigation Vulnerability Model and Cluster Analysis)

  • 남원호;김태곤;홍은미
    • 한국농공학회논문집
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    • 제57권1호
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    • pp.59-67
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    • 2015
  • Because reservoirs that supply irrigation water play an important role in water resource management, it is necessary to evaluate the vulnerability of this particular water supply resource. The purpose of this study is to provide water supply risk maps of agricultural reservoirs in South Korea using irrigation vulnerability model and cluster analysis. To quantify water supply risk, irrigation vulnerability indices are estimated to evaluate the performance of the water supply on the agricultural reservoir system using a probability theory and reliability analysis. First, the irrigation vulnerability probabilities of 1,346 reservoirs managed by Korea Rural Community Corporation (KRC) were analyzed using meteorological data on 54 meteorological stations over the past 30 years (1981-2010). Second, using the K-mean method of non-hierarchical cluster analysis and pre-simulation approach, cluster analysis was applied to classify into three groups for characterizing irrigation vulnerability in reservoirs. The morphology index, watershed area, irrigated area, and ratio between watershed and irrigated area are selected as the clustering analysis parameters. It is suggested that the water supply risk map be utilized as a basis for the establishment of risk management measures, and could provide effective information for a reasonable decision making on drought risk mitigation.

농업용 저수지 둑 높이기에 따른 홍수조절효과 분석 (Effects of Agricultural Reservoir Rehabilitation on their Flood Control Capacities)

  • 전상민;강문성;송인홍;황순호;김계웅;박지훈
    • 한국농공학회논문집
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    • 제55권6호
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    • pp.57-68
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    • 2013
  • About 74 % of reservoirs in Korea are older than 40 years and their storage capacities have been decreased substantially. As part of reservoir reinforcement, the dam heightening project has been ongoing for about 110 reservoirs. The main purpose of the dam heightening project is to secure additional environmental water, while improving flood control capacity by gaining additional storage volume. The objective of this study was to evaluate reservoir flood control capacity changes of dam heightening reservoirs for effective management of additional storage volume. In this study, 13 reservoirs were selected for reservoir simulation of 200 year return period floods. Rainfall data of 1981-2100 were collected and divided into 4 periods (1981-2010; 1995s, 2011-2040; 2025s, 2041-2070; 2055s, 2071-2100; 2085s). Probability rainfalls and 200yr design floods of each period were calculated using FARD2006 and HEC-HMS. Design floods were used as inputs of each reservoir simulation using HEC-5. Overall, future probability rainfalls and design floods tend to increase above the past 1995s. Control ratios were calculated to evaluate flood control capacities of reservoirs. As a result, average flood control ratios were increased from 32.6 % to 44.2 % after dam heightening. Control ratios were increased by 12.7 % (1995s), 12.4 % (2025s), 10.3 % (2055s) and 10.9 % (2085s). The result of this study can be used as a basis for establishing the reservoir management structure in the future.

농업용 저수지의 소수력 개발을 위한 경제성 분석 (Economic Feasibility Analysis for Development of Small Hydropower Using Agricultural Reservoirs)

  • 우재열;김진수;장훈;김영현
    • 한국농공학회논문집
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    • 제53권2호
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    • pp.53-60
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    • 2011
  • This study was conducted to investigate the effect of hydropower factors (watershed, gross head), operation ratio and unit electricity cost on the benefit-cost ratio (B/C ratio) of small hydropower using agricultural reservoirs. The equation of B/C ratio was expressed as a function of watershed area, gross head, operation ratio and unit electricity cost. The benefit increased with watershed area, gross head and unit electricity cost, while the cost increased with watershed area and gross head but decreased with operation ratio. The B/C ratio increased with watershed area, gross head, operation ratio and unit electricity cost. While the effect of gross head on the B/C ratio decreased with watershed area, the effect of operation ratio and unit electricity cost on the B/C ratio increased with watershed area. The operation ratio is an important factor to affect the B/C ratio and therefore we need to develop hydropower for the heightened dams to expect high operation ratio due to continuous water release. The unit electricity cost is also an important factor to affect the B/C ratio and the B/C ratio was always below 1 unless unit electricity cost is over 60 Won/kWh under given conditions. The reservoirs with economic feasibility for small hydropower development were three in 21 when the equation of B/C ratio was appled to the study reservoirs. The results can be used to choose the appropriate reservoir with economic feasibility for development of small hydropower.

수정 Penman 및 Penman-Monteith 논벼 증발산량 방법 적용에 따른 농업용 저수지 용수공급능 분석 (Analysis of Water Supply Reliability of Agricultural Reservoirs Based on Application of Modified Penman and Penman-Monteith Methods)

  • 조건호;한경화;최경숙
    • 한국농공학회논문집
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    • 제61권6호
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    • pp.93-101
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    • 2019
  • This study aims to analyze the influences of applications of two different evapotranspiration (ET) estimation methods on the irrigation water requirements (IWR) for paddy rice and water supply reliability of agricultural reservoirs. The modified Penman (MP), traditional method, and the Penman-Monteith (PM), the new adopted method, were applied on 149 reservoirs located in Honam province for this study. The weather date was used from 1987 to 2016, and analysed the trends of temperature and rainfall during rice growing season between past and current 10 years respectively. The increased average temperature and rainfall were observed from the current 10 years compared to the past years. This phenomena impacts on the results of ET and IWR estimations with decreased IWR obtained from high rainfall regions and increased ET obtained high temperature regions. For the comparisons of application results of two ET approaches, the PM method showed lower ET and IWR, and hence more reliable storage capacity of the reservoirs respect to water supply to paddy fields. The results also showed that the influences of different ET methods applications on the water supply reliability of reservoirs are negligible for the cases of over 3.7 watershed ratio and 670 mm unit reservoir storage, while significant variations of the results obtain from the applications between two ET approaches for the opposite cases. Further studies are necessary to consider various field conditions for practical applications of the PM method estimating ET in the fields of paddy farming.