• 상하수도학회지
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• 제21권1호
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• pp.131-138
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• 2007

A rainwater utilization facility consists of its catchment area, treatment facility, storage tank, supply facility and pipes in general. The rainwater storage tank which occupies the largest area of the facility has been usually considered quantitatively for determining the storage capacity. Hence, there is little information on water quality improvement by sedimentation in a rainwater storage tank in operation. In this study, we measured the rainwater quality in a rainwater storage tank in operation during late spring and summer, and showed water quality improvement of turbidity removal of 25~46% by sedimentation in a rainwater storage tank under a fixed water level without inflow and outflow after runoff ceased. It is necessary to have a considerable distance between the inlet and outlet of the tank and, if possible, it is recommended that the design should allow for an effective water depth of over 3 m and supply rainwater near the water surface. The operation method which increases the retention time by stopping rainwater supply for insuring low turbidity is recommended when the turbidity of rainwater runoff is high. And also more efficient operation and maintenance of the rainwater utilization facility is expected through the tailored design and operation of the facility considering particle removal and behavior.

• 한국환경과학회지
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• 제12권3호
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• pp.359-366
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• 2003

Ecological society and energy conservative systems has become a subject of world wide attention. To examine the technologies of such systems as resource recycling society, this study is proposed for using rainwater as energy source and water resources in urban area. Useful informations for planning of utilizing rainfall as energy source, water resources, emergency water and controlling flood are discussed with model systems in urban area. It is calculated that the rate of utilizing rainwater, amounts of utilizing rainwater, substitution rate of supply water, amounts of overflow rainwater according to rain storage tank volume. By applying the past weather data, The optimum volume of rain water storage was calculated as 200m$^3$ which mean no benefits according to the increase of storage tank volumes. For optimum planing and control method at the model system, several running method of rainwater storage tank was calculated. The optimum operating method was the using weather data as 3hours weather forecast.

• 상하수도학회지
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• 제22권2호
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• pp.233-238
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• 2008

Recently, rainwater harvesting facilities have increasingly constructed mainly in elementary schools and government buildings. Nevertheless, few methods are available for efficient planning and design of rainwater harvesting facilities by considering the weather conditions and purpose of rainwater management in each site, which may lead to a construction of uneconomic facilities. The current method estimates the size of rainwater storage tank by multiplying the size of building or plottage with a certain ratio and has many limitations. In this study, we first developed a method for planning and design of rainwater storage facilities using $Rainstock^{TM}$ model, which is based on mass balance, and economic analysis. Then, the model was applied for the design of a rainwater harvesting facility in a building with the catchment area of $1,000m^2$. The model calculation indicated that the economic feasibility of rainwater harvesting depends on not only the size of storage tank but also the water usage rate. When the water usage rate is $1m^3/day$, the rainwater harvesting facility is not cost-effective regardless of the size of the storage tank. With increasing the water usage rate, the economical efficiency of the facility was improved for a specific size of the storage tank. Based on the model calculation, the optimum tank sizes for $5m^3/day$ and $10m^3/day$ of water usage rates were $24m^3$ and $57m^3$, respectively. It is expected that the model is useful for optimization of rainwater storage facilities in planning and designing steps.

• 한국건축시공학회지
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• 제5권4호
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• pp.165-171
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• 2005

Nowadays, a source of all water, which has been spent by a lot of people, is the rainwater The rainwater is directly relating human being' life. According to how to use rainwater. human being' life is abundant or poor. Due to the lack of underground filtration quantity, the water circulation of the city is discontinued and the underground ecosystem is destroyed. This study suggest that the unused underground space of building and temporary structure can be used into rainwater storage tank in the facility to use rainwater. Moreover, in this study, while the building is constructed, It is showed that the water used in construction can be replaced in the rainwater.

• 한국방재안전학회논문집
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• 제12권4호
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• pp.1-13
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• 2019

최근 기후변화로 인해 강우강도 및 빈도의 증가에 따른 국지성 집중호우의 피해가 증가함에 따라 초기 우수에 대응할 수 있는 시설물 설치가 필요한 실정이다. 이를 위해, 빗물을 직접 유출하지 않고 저류 시키는 저영향 개발(Low Impact Development)기법을 적용한 시설물 설계 및 수치모형을 이용한 유출저감효과 검토에 관한 연구가 많이 진행되어 왔다. 그러나 대부분의 연구는 유출저감효과에 대한 검토만 수행된 반면, 시설물에 유입되는 유량에 의한 흐름특성 변화 검토 및 안정성 검토에 관한 연구는 미비한 실정이다. 이에 본 연구에서는 LID 기법이 많이 적용되고 있는 회전교차로를 대상으로 하여, 회전교차로 내의 우수저류조의 관망시스템의 안정성 검토를 3차원 수치모형인 FLOW-3D를 사용하여 검토하였다. 또한 우수저류조의 최적의 설계방안 도출을 위하여 우수저류조의 수를 증가하여 용량증가에 따른 유속과 동압의 변화를 검토하고 설계기준과 비교하였다. 우수저류조의 제원 및 유입유량은 선행연구에서 제시된 값을 적용하여 수치모의를 수행한 결과, 유속은 저류조 설치개소 수가 증가할수록 빨라지는 것을 확인하였고, 대부분 설계기준 범위 안에 유속이 형성되는 것을 확인하였다. 다만 추가 저류조가 3개 이상일 경우는 추가저류조관에서 유속이 3.44 m/s가 발생하여 설계유속의 허용범위를 초과하였고, 유속의 증가율도 일정해지는 것으로 나타났다. 난류강도 및 바닥전단력 비교의 경우, 저류조 설치 개소수가 증가함에 따라 바닥전단력이 한계소류력보다 크게 나타나 유입토사의 침전은 발생하지 않을 것으로 예상되나 난류강도의 크기가 작아져 플록(Floc)형성으로 인한 토사 침전이 발생할 수 있음을 고려해야한다. 최종적으로 유속을 이용한 동압 산정 결과를 우수관 설계에 일반적으로 사용되는 압력관의 허용내압과 비교하였을 경우, 동압이 허용내압보다 작게 나타났다. 이를 통하여 본 연구에서 제안한 우수저류조 제원으로 설계할 경우 추가 저류조를 2개까지 설치하는 것이 가장 적합한 것으로 나타났다. 이는 저류조를 계속하여 설치하게 되면 배수가 원활해져 관내 유속이 빨라지고, 유속증가로 인하여 관의 마모손상 등의 문제가 일어날 수 있기 때문이다. 그러나 본 연구는 저류조의 제원 및 우수의 유입량을 가정하였고, 단순히 저류조를 추가하여 저류조 설계방안을 도출한 한계점이 있어 향후에는 다양한 저류조 형태 및 우수유입 시나리오를 적용하여 검토한다면 보다 효율적인 설계방안 도출이 가능할 것으로 기대된다.

• 한국물환경학회지
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• 제24권2호
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• pp.230-238
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• 2008

This study evaluated the economic aspect of the rainwater harvesting facilities by hydrologically analyzing the inflow, rainwater consumption, rainfall loss, tank storage, and overflow time series to derive the net rainwater consumption and the number of days of rainwater available. This study considers several rainwater harvesting facilities in Seoul National University, Korea Institute of Construction Technology and Daejon World Cup Stadium and the results derived are as follows. (1) Increasing the water consumption decreases the number of days of rainwater available. (2) Due to the climate in Korea, a larger tank storage does not increase the amount and the number of days of water consumption during wet season (June to September), but a little in October. (3) Economic evaluation of the rainwater harvesting facilities considered in this study shows no net benefit (private benefit). (5) Flood reduction effect of rainwater harvesting facilities was estimated very small to be about 1% even in the case that 10% of all the basin is used as the rainwater collecting area.

• 환경영향평가
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• 제15권2호
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• pp.111-119
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• 2006

In Korea, an environment-friendly concept of "rain re-cycling" was initially introduced in apartment complex planning and designs in the late 1990s. Although its application cases are extremely few, with the growing importance of rainwater utilization, introduction of rainwater management facilities in urban areas began to drawn keen attention. In urban areas also, plans to introduce rainwater management facilities in apartment complexes as infrastructure improving living environment, such as sewage treatment facilities are very urgently required. In order to introduce rainwater management facilities as infrastructure in an apartment complex, apartment complex cases that had introduced the facilities were reviewed first. In this study, a few applied rainwater management facilities in an apartment complex were surveyed(Infiltration barrel, Rubble porosity storage tank, Underground storage tank). As a result, problems in introducing rainwater management facilities in apartment complexes in Korea were identified.

• 한국안전학회지
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• 제28권4호
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• pp.107-113
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• 2013

The design of rainwater storage system unit to manufacture its reservoir tank was tried, the simulation to predict of their structural strength was carried out. Rainwater storage system unit should be easy to their machinability, transport and assemble. Especially, their structure was able to secure the water storage space, withstand loads and easily response to pollution. Considering these various requirements, they have to Doria-pillar structure of the Roman architectural style because these designs could disperse the loads which are applied to them. Therefore, the six kinds of models possible were proposed. Several boundary conditions were given to each model. Their structural strength was predicted through the simulation on their stress and the displacement distribution to constant load. From the evaluated data, the structure which has a large pillar in the central of unit and four small pillars each corner was the best.

• 상하수도학회지
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• 제19권2호
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• pp.173-180
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• 2005

In this study, quantity and quality of collected rainwater by the ground collection system were investigated and the Rainwater Collection Prediction Model was developed to predict the amount of collected rainwater. The quantity of collected rainwater in the collection system was 9516 L(38.2%) and the quantity of infiltrated rainwater in the collection system was 9946 L(40.2%) through $25m^2$ area for the study period, respectively. Average turbidity of collected rainwater in collection system was 2.2 NTU, and average turbidity of infiltrated rainwater in collection system was 2.3 NTU for study period, respectively. The predicted amount by the model and the actual collected amount were 9842.4 L and 9516 L, which were very close showing that prediction was excellent. The optimal rainwater storage tank volume was simulated with a certain consumption condition for various cities with different rainfall patterns.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.386-389
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• 2013

Under climate change and urbanization, rainwater harvesting (RWH) systems are emerging as an alternative source of water supply because of growing concern about water sustainability. RWH systems can satisfy the various watering needs and provide the environmental benefits of lessening the damages from flood, drought, and runoff. The economic success of a RWH system is vitally concerned with the determination of the design capacity of storage tank to be built in the system. The design capacity is determined by the factors of average annual rainfall, period of water scarcity, and water price during the whole life-cycles. Despite the high uncertainties inherent in these factors, the current engineering design of RWH system construction often assumes that storage tanks should be built all at once. This assumption implicitly ignores the managerial flexibility in responds to the future as new information comes out-the right to build storage tanks stage by stage depending on the evolution of demand. This study evaluates the value of a multistage storage tank construction using a real option approach. A case study involving a typical RWH system construction in Jeonju, the Republic of Korea is conducted. The managerial flexibility obtained from the real option perspective allows engineers to develop investment strategies to better cope with the issue of water sustainability.