• 한국수자원학회논문집
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• 제46권11호
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• pp.1069-1078
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• 2013

울산시의 주요 생활용수공급댐인 사연댐 상류 수몰지역 내에 국보 285호인 반구대 암각화가 위치하고 있다. 표고 53~57 m에 위치한 암각화 보존을 위한 여러 가지 방안 중, 사연댐 수위를 60 m에서 52 m로 낮추어 물 밖으로 끄집어내는 안이 주로 검토되어 왔다. 댐의 수위를 인위적으로 조절하는 경우 저수량 및 용수공급량 감소와 더불어 부영양화로 인해 수질이 나빠지게 된다. 본 연구에서는 사연댐 수위조절에 따른 수질악화로 댐의 기능상실과 수질변화로 인해 예상되는 여러 가지 문제점을 검토하였다. Vollenweider 모델과 CSTR (Continuous Stirred Tank Reactor) 모델을 이용하여 수위조절시 변화가 예측되는 대표적인 수질지표인 BOD 및 COD 그리고 조류성장의 주 원인이 되는 총인과 총질소의 농도변화를 분석하였다. 그 결과 사연댐의 수위를 60 m에서 52 m로 조절하는 경우, COD의 농도는 약간 낮아지지만 총질소와 총인은 약 130% 이상 농도가 증가되는 것으로 나타났다. 이러한 변화는 심각한 조류문제를 일으킬 수 있으며, 사연댐의 수질관리를 영양염류의 농도를 대상으로 하는 경우 수질이 악화되는 것으로 나타났다.

• 지질공학
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• 제24권1호
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• pp.53-67
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• 2014

댐붕괴로 인하여 빚어지는 홍수위험지도 작성에서 물리적 현상을 재현해내기 위하여 수치모형이 사용되는 것이 일반적이다. 이때 모형의 정확도는 저수지의 수량과 댐붕괴 형성 및 진행을 포함한 모형의 물리적 구조, 입력인자 및 매개변수의 신뢰도에 의하여 결정되기 마련이다. 특히 입력인자 및 매개변수는 모형을 이용하기 이전에 미리 결정하여 입력하게 되며 사용자의 판단과 주관에 의지하므로 주의가 요구된다. 이 연구에서는 댐붕괴 모형을 FLO-2D와 연동하여 홍수 침수모의를 실시할 때에 댐붕괴 모형에서 세 개의 매개변수(붕괴각도 ${\theta}$, 저수지 형상계수 P, 붕괴율 k가 FLO-2D의 침수모의(침수범위, 침수깊이 등)에 어떻게 영향을 미치는 가를 살펴보았다. 붕괴각도 ${\theta}$는 FLO-2D의 침수모의에 있어 낮은 영향을 미치나 저수지 형상계수 P와 붕괴율 k는 중대한 영향을 미치는 것으로 나타났다. 이 연구는 향후 댐붕괴에 의한 홍수 위험의 피해를 저감하는데 기여할 것이다.

• 한국수자원학회논문집
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• 제38권9호
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• pp.747-760
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• 2005

본 연구에서는 한강수계를 대상으로 1차원 동역학적 홍수추적모형인 DAMBRK 모형을 이용하여 상류댐 및 중간댐의 영향을 고려한 홍수추적을 실시하였다. 또한 중간댐에서의 홍수추적기법의 타당성을 검토하기 위해서 다양한 형태의 가상의 저수지에 대한 dynamic routing과 storage routing에서의 유출량을 검토하였다. 모형의 적용성을 검증하기 위해서 1990년 9월 및 1995년 8월 홍수사상에 대한 홍수추적을 실시하여 실측값과 비교${\cdot}$검토하였다. 한강수계에 극한홍수사상과 각 하천의 설계홍수량을 적용하여 중간댐들의 영향을 고려한 홍수추적을 수행하여 그 결과를 도시하였다. 본 연구를 통해서 향후 한강유역에서의 홍수예경보와 효율적인 홍수조절을 통한 홍수정보시스템 확립에 크게 기여할 것으로 판단된다.

• 물과 미래
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• 제27권4호
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• pp.69-84
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• 1994

본 연구의 목적은 갈수기와 풍수기간동안 유입량의 변화에 맞추어 저수지를 최적으로 운영하도록 방류와 저류량을 조절하는 실시간 저수지 운영율을 결정하는 것이다. 최적방류와 저유의 결정은 많은 저수지 운영목적을 충족시켜 목표들을 달성해야 하는 복잡한 의사결정 문제이다. 저수지에서 저류와 방류의 목표는 저수지로 유입되는 유입량의 정도에 따라 달성이라는 충족과 초과 및 미달이라는 편차가 발생한다. 이 편차를 손실로 보아 이 손실에 상응하는 벌과점을 부여하여 벌과손실이 최소가 되도록 저수지의 최적운영을 시도하는 것이다. 본 논문은 대청댐 운영목표로부터 편차손실 곡선을 작성하였으며 곡선의 경사를 손실계수로 운영모형의 목적함수에 반영하여 선형계획기법으로 대청댐 운영에 적용하여 보았다. 그 결과 저수지 운영에서 편차곡선을 이용해서 저류와 방류의 상반성을 반영할 수 있었으며, 유입량의 조건에 따른 목표달성의 정도와 운영의 간편성을 분석함으로 실시간 저수지 운영에서 의사결정을 위한 최적 기준의 설정방향을 제시하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.40-48
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• 2008

The Waimea Basin is located on the northern tip of the South Island of New Zealand. It is a highly productive area with intense water use with multi-stakeholder interest in water. Irrigation from the underground aquifers here makes up the largest portion of used water; however the same aquifers are also the key urban and industrial sources of water. The Waimea/Wairoa Rivers are the main sources of recharge to the underlying aquifers and also feed the costal springs that highly valued by the community and iwi. Due to the location of the main rivers and springs close to the urban centre the water resource system here has high community and aesthetic values. Recent enhanced hydrological modelling work has shown the water resources in this area to be over allocated by 22% for a 1:10 year drought security for maintaining a minimalistic flow of 250 l/s in the lower Waimea River. The current irrigated land area is about 3700 hectares with an additional potential for irrigation of 1500 hectares. Further pressures are also coming on-line with significant population growth in the region. Recent droughts have resulted in significant water use cutbacks and the threat of seawater intrusion in the coastal margins. The Waimea Water Augmentation Committee (WWAC) initiated a three year stage 1 feasibility study in 2004/2005 into the viability of water storage in the upper parts of the catchment for enhancing water availability and its security of supply for consumptive, environmental, community and aesthetic benefits downstream. The project also sought to future proof water supply needs for the Waimea Plains and the surrounding areas for a 50 - 100 year planning horizon. The broad range stage 1 investigation programme has identified the Upper Lee Catchment as being suitable for a storage structure to provide the needs identified and also a possibility for some small scale hydro electricity generation as well. The stage 2 detailed feasibility investigations that are underway now (2007/2008), and to be completed in two years is to provide all details for progressing with the next stage of obtaining necessary permits for construction and commissioning a suitable dam.

• 한국동물위생학회지
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• 제35권3호
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• pp.183-189
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• 2012

Tsutsugamushi disease or scrub typhus cause by Orientia tsutsugamushi is an endemic disease in Korea. Chigger mites and field rodents play roles in transmission of the disease by the vector and host of the agent. The purpose of this study is to investigate the density of the chigger mites and field rodents due to environmental factors such as temperature, relative humidity, soil thickness and the various vegetations to the 9 field rodent collection sites. The total 62 field rodents was captured by the Sherman collapsible traps from April to October 2009 at the Jangseong of Jeonnam Province, Korea. The trapping rate of the field rodents by the different collecting sites was dominant at subside storage water (24%), bush near by dam (22%), bank around field (20%), followed by 18% of grassy field and surround cattle shed. The distribution of chigger mites by the different collecting sites was the highest at Bush near by dam (28.7%). And the sites of subside storage water, bank around field and surround cattle shed were 20.4%, 18.8%, 16.4%, respectively. On the other hand the collecting sites of stream bank and ridges between rice paddies were not collected. The temperature to the collecting sites was showed $24.1^{\circ}C$ in June and $24.2^{\circ}C$ in October which was higher than April ($10.6^{\circ}C$), whereas lower than May ($25.3^{\circ}C$) and September ($26.8^{\circ}C$). The highest number of mites was collected at $24.2^{\circ}C$ and 46.6% relative humidity in October. The chigger mites and field rodents were highly collected between 18 and 24% at the sites where are loosely in the superficial layers of the soil from 8.0 cm to 10.2 cm. Total 25 species of vegetation were distributed at the collecting sites. In the present study, strong evidence was found that bank around field and grassy field were provided for the prevalence sites of tsutsugamushi disease.

• 한국농공학회논문집
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• 제61권3호
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• pp.101-112
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• 2019

This study developed selection criteria of small-scales reservoirs, having under $300,000m^3$ storage capacity, for the Emergency Action Plan(EAP) establishment in order to reduce the disaster risks of the reservoir's failures. Those reservoirs are out of ranges of Korean EAP establishment standard, but have potential risk of disasters as they have often failed by the recent extreme rainfall events and earthquakes, causing economical and life losses. The problem of reservoir aging is also one of the reasons of them. In this study, the developed selection criteria of small reservoirs for EAP establishment are storage capacity, embankment height, reservoir age, heavy rain factor and earthquake factor. These criteria were selected based on the review of the existing EAP establishment guidelines, analysis of the past dam failure cases, and the previous related studies. The quantification of these criteria were conducted for the practical applications in the fields, and applied to 67 previous failures in order to investigate the relation of each criteria with these failures. The earthquake factor found to be the highest relations followed by heavy rain factors, combination of earthquake and heavy rain factors, and reservoir age. The classification was made as observation and review groups for EAP establishments based on overlapping numbers of each criteria. This classifications applied to 354 reservoirs designated as having the potential disaster risk by MOIS, and showed 38.4% of observation and 11.9% of review groups. Anticipatory monitoring and regular inspection should be made by professional facility managers for the observation group, and necessity of EAP establishment should be assessed for the review group based on the downstream status and financial budget.

• Elastomers and Composites
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• 제37권3호
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• pp.183-191
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• 2002

우수한 신장성과 탄성복원 능력으로 여러 산업분야에 방진, 제진, 충격흡수 및 완충재료로 널리 사용되고 있는 고무재료에 대하여 주파수, 변형률 진폭 및 온도변화가 동특성에 미치는 영향을 실험을 통하여 검토하였다. 동특성 시험은 5종류의 경도에 대하여 인장.압축시험과 전단시험용의 천연고무 시험 편으로 비 공진법으로 수행하였다. 시험결과, 경도가 높을수록 동적 특성 값들이 크게 나타났으며 저장탄성계수와 손실계수는 주파수가 증가할수록 서서히 증가하였으며 변형률 진폭이 커질수록 감소하였다. 또한, 온도 특성을 $-50^{\circ}C$ 영역에서 저장탄성계수가 급격히 상승하며 손실계수가 최대로 나타나는 전이역임을 알 수 있었다.

• 한국물환경학회지
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• 제22권6호
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• pp.1094-1100
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• 2006

In this study, the reservoir sediment reduction methods for long-term operation are proposed by the analysis of both sediment deposit characteristics and sediment reduction effect by each method. To that end, a flowchart for sediment analysis in reservoir is established and sediment deposit is simulated by SMS-SED2D model. The sediment reduction methods which are sediment passing (sluicing), flushing, trapping, bypassing and mechanical removal are used. From the simulation results, the effective method for sediment reduction is operation which is coupled by both sediment passing with sand gate and sediment trapping with debris dam. And If sediment flushing will be used once a year after 50 years, conservation storage can be secured until 100 years after dam construction.

• 한국지진공학회논문집
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• 제20권4호
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• pp.201-209
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• 2016

Damages of large embankment dams by recent strong earthquakes in the world highlight the importance of seismic security of dams. Some of recent dam construction projects for water storage and hydropower are located in highly seismic zone, hence the seismic performance evaluation is an important issue. While state-of-the-art numerical analysis technology is generally utilized in practice for seismic performance evaluation of large dams, physical modeling is also carried out where new construction technology is involved or numerical analysis technology cannot simulate the behavior appropriately. Geotechnical centrifuge modeling is widely adopted in earthquake engineering to simulate the seismic behavior of large earth structures, but sometimes it can't be applied for large embankment dams due to various limitations. This study proposes a dynamic centrifuge testing method for large embankment dams and evaluated its applicability. Scaling relations for a case which model scale and g-level are different could be derived considering the stress conditions and predominant period of the structure, which is equivalent to previously suggested scaling relations. The scaling principles and testing method could be verified by modified modeling of models using a model at different acceleration levels. Finally, its applicability was examined by centrifuge tests for an embankment dam in Korea.