• Journal of Korean Society of Water and Wastewater
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• v.24 no.6
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• pp.691-701
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• 2010

As the water-cycle is transformed by increasing of the impermeable area in process of urbanization, decentralized rainwater management facilities(infiltration, harvesting and retention facilities) as source control are considered to be a method of restoring water-cycle of urban and reducing runoff. SWMM model was used to analyse the change of water-cycle structure before and after development in A new town watershed. Modified SWMM code was developed to apply infiltration facilities. The modified SWMM was used to analyse the change of water-cycle before and after infiltration trench setup in AJ subcatchment. Changes of the impervious area by development and consequent increase in runoff were analyzed. These analyses were performed by a day rainfall during ten years from 1998 to 2007. According to the results, surface runoff increased from 51.85% to 65.25 %, and total infiltration volume decreased from 34.15 % to 21.08 % in A newtown watershed. If more than 80 infiltration trenches are constructed in AJ subcatchment, the low flow and the drought flow increases by around 47%, 44%, separately. The results of this study, infiltration trench is interpreted to be an effective infiltration facility to restore water-cycle in new town.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.455-460
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• 2009

A number of factors combine to make ultraviolet radiation a superior means of water purification for ground water, rainwater harvesting systems and so on. Ultraviolet radiation is capable of destroying all types of bacteria. Additionally, ultraviolet radiation disinfects rapidly without the use of heat or chemical additives which may undesirably alter the composition of water. In a typical operation, water enters the inlet of a UV lamp and flows through the annular space between the quartz sleeve and the outside chamber wall. The irradiated water leaves through the outlet nozzle. Several design features are combined to determine the dosage delivered. The first is Wavelength output of the lamp, the Second is Length of the lamp - when the lamp is mounted parallel to the direction of water flow, the exposure time is proportional to the length of the lamp, the third is Design water flow rate - exposure time is inversely related to the linear flow rate, the forth is Diameter of the purification chamber - since the water itself absorbs UV energy, the delivered dosage diminishes logarithmically with the distance from the lamp. In this paper, It describe the how to design optimal UV disinfection device for ground water and rainwater. To search the optimal design method, it was performed computer simulation with 3D-CFD discrete ordinates model and manufactured prototype. Using proposed design method manufactured prototype applied to disinfection test and proved satisfied performance.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.457-457
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• 2015

최근, 우리나라에서는 효과적인 수자원 관리와 추가적인 수원 확보 차원에서 빗물 재이용에 관한 관심이 크게 증대되고 있다. 하지만 국내의 관련된 제도와 기술 지침은 단지 규제 측면에서 빗물이용시설을 설치하도록 제시하고 있어 빗물이용시설의 실제 사용을 고려한 계획이 배제되어 있다. 본 연구의 목적은 실용적인 빗물이용시설의 계획을 위해 SWMM을 이용하여 빗물 재이용의 수요(빗물 재이용 목표량)와 공급(연간 강우량과 패턴)을 반영한 설계 방법을 제시하는 것이다. 이를 위해 SWMM 내에 구현되어 있는 빗물통 모의에 관한 수식을 이용하되, 수식을 목적에 맞도록 일부 변형하여 활용하였다. 그리고 빗물이용시설의 규모는 설정한 목표량을 만족할 수 있는 최소의 크기로 결정하는 것이 적절하고, 장기간의 강우자료를 이용한 물수지 석이 요구되므로 이를 고려하였다. 본 연구에서 제시한 빗물이용시설의 설계 방법은 송산 그린시티 동측지구에 계획된 빗물이용시설의 규모 결정에 활용되었다. 빗물 재이용의 목표량이 일정한 경우, 빗물이용시설의 크기가 커질수록 빗물 재이용 가능량은 로그함수의 형태로 증가하여, 빗물이용시설이 특정 규모 이상으로 커지더라도 빗물 재이용 가능량은 더 이상 증가하지 않는 임계점이 나타난다(그림 1). 따라서 빗물이용시설은 이러한 임계점이 나타나는 규모 정도로 설계하는 것이 합리적이다. 본 연구에서 제시한 빗물 재이용을 고려한 빗물이용시설의 계획은 빗물이용시설을 보다 합리적으로 계획하는데 도움을 줄 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.418-418
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• 2022

본 연구에서는 수문학적 물수지 분석을 통한 물수요-공급 시계열 분석을 수행하여 빗물이용률을 산정하였다. 물수지 분석 도구를 개발하였으며, 이를 통해 빗물이용시설 공급충족률(필요수량 대비 빗물이용량), 빗물보장률(전체일수 대비 빗물이용일수), 빗물이용률(빗물이용시서용량 대비 빗물이용가능량)에 대해 분석을 수행하였다. 업무시설, 학교, 체육시설(공원), 공동주택에 대해 수요처별 수요 시나리오를 작성하였으며, 고수요 75%, 중수요 50%, 저수요 25%를 적용하였다. 시나리오별 실제 용량과 기준용량에 따른 빗물이용률을 비교함으로써 현재 설치된 빗물이용시설이 잘 계획되었는지, 과소 계획되었는지 파악할 수 있다. 빗물이용률 분석을 위해 빗물이용시설 유형별 2개소씩 선정하였으며, 빗물이용시설 실제용량 및 기준용량(집수면적(m²)×0.05 적용)에 따른 수요 시나리오별 빗물이용률을 비교하였다. 이와 같이 물수지 분석 도구를 이용하면 다양한 시나리오 적용에 따른 운영 결과를 향후 설치될 빗물이용시설의 설치 이전에 확인하여 최적 운영방안 도출 및 저류조 용량 계획에 참고할 수 있을 것으로 판단된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.40-47
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• 2018

Porous walkway blocks are constructed for the purpose already, but reserved water is easily consumed due to the bigger permeability than necessary. Furthermore, porous structure reduces the strength of blocks, which resulting cracking and settlements in walkways. In this study, we suggested a solution for given problems by determination for the location of minimum principal stress in walkway blocks against moving foot loads in order to design and verifying the determined location of minimum principal stress. An optimum design with a verification example for determined location of minimum principal stress have been presented in a two dimensional Block member on elastic foundation for pedestrian walkway for reserving water inside. The minimum value for sum of shear forces is found when ${\times}1$ is 58.58 mm(30% of total span, 200mm), while the minimum deformation is located at ${\times}2=80mm$(70% of total span, 200 mm). In a modified model, When moving boundary condition(walkway foot loads) is located at ${\times}1$(=0 mm), the location of minimum principal stresses is found at 168 mm( 84% of span, 200 mm), in which the stress concentration due to the foot load is modeled as two layers of distributed loads(reactions of foundation modeled as springs). Consequently, zero deformed reservoirs for rainwater on the neutral axis (${\times}2=167mm$) has been determined in the modified model with three dimensional FEM analysis verifications.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.9
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• pp.623-629
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• 2012

The objective was to evaluate the quality of harvested rainwater of the roofing materials used and the presence of lichens/mosses on the roofing surface. This experiment was studied in the field where five pilot structures with different roofing materials (i.e., wooden shingle tiles, wooden shingle tiles (including mosses), concrete tiles, clay tiles [Gi-Wa] and slate tiles) were installed. As a result, the clay tiles [Gi-Wa] was found to be the most suitable for rainwater harvesting applications. It was due to the disinfection from ultraviolet light and high temperature according to characteristic of roofing materials. Comparison with quality of rainwater on that wooden shingle tiles with and without including mosses, which may affect the concentration of and wooden shingle tiles including mosses, mosses may affect concentration of TOC, nitrate, and sulfate. Additionally, the average concentration of asbestos was determined to be measured at $0.002/cm^3$ for the slate tiles. The value satisfied with it met the Ministry of Environment's Multi-use facility standard and Ministry of Labor's Office standard ($0.01/cm^3$).

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.111-118
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• 2020

This study developed a rainwater harvesting system for the irrigation of upland on sloping area. The assessment of water supply capacity was evaluated in farm field experience. This system consists of a water catchment device and a collapsible storage tank. The water catchment device was designed to collect runoff water in natural channel of 500 mm width into a pipe of 50 mm inner diameter. The device has funnel-shaped plan and cross-section of square. The storage capacity of the collapsible water tank was caculated to meet the water demand for irrigation in 30 a cultivated land for 10-year frequancy drought. The tank has a cuboid shape with a capacity of 30 ㎥, 5 m in width and length, 1.2 m in height. This system can supply 92% of the water required for drop irrigation of red pepper and 88% of the water required for drop irrigation of onions in 30 a cultivation land during the month of May and June. In the case of 16-dry days of 10-years frequency, this system is capable to irrigate 100% of required water for red pepper and onion, 76.7% of required water for Omija (Schisandra chinensis), and 51.5% of required water for autumn kimchi cabbage.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.935-947
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• 2011

In the era of climate change, the feasibility of a 'multi-functional storage facility' was evaluated in terms of various key performance indices such as flooding prevention effects, urban pollution reduction effects, and rainwater harvesting effects. As a result, the Korea Ministry of Environment introduced a new concept of 'multi-functional storage facility' for sewer flooding prevention and urban non-point pollution reduction. Prior to introducing these infrastructure (a large underground storage facility), the more details were needed to be examined carefully in all of technical aspects of construction and management. It was also well known that the validity of installation of 'multi-functional storage facility' was sometimes weakened because of a low B/C ratio.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.501-501
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• 2022

2014년 개정된 물의 재이용 촉진 및 지원에 관한법률(이하, 물재이용법)에 따라서 빗물이용시설의 수는 꾸준히 증가하고 있는 추세이나 실제 연간사용량의 경우 연별 증가량은 미미하다. 또한 2016년도 환경부 하수도 통계에 따른 2,043개의 빗물이용시설 중 집수면적 미파악시설의 749개, 여과시설 유무 미파악시설 564개, 연간 운영비 산출 불가능 시설 1,843개, 연강 사용량 미집계 시설 905개로 관리실태가 부실함을 확인할 수 있다. 이에 빗물이용시설의 설치·운영 실태조사 및 문제점을 분석하고 빗물이용이 비교적 활성화 된 시설을 대상은 현장조사를 수행을 통해 빗물이용시설의 현황을 분석하고 현실적인 여건을 반영하여 빗물이용을 활성화할 수 있는 방안을 마련하고자 하였다. 물재이용법에 따른 빗물이용시설 법정의무대상시설의 빗물활용처는 전체의 약 92%가 조경요수로 활용하고 있으며, 다음으로 청소화장실용수(약 3%)로 활용하고 있다. 건축물 용도에 따라서 골프장, 공공기관청사/공공업무시설, 대규모점포, 실내체육관/종합운동장, 학교의 경우 건축물 용도별로 각 30% 정도가, 공동주택의 경우 약 60%가 빗물이용시설을 활용하고 있음에도 빗물을 사용하지 았는 것으로 파악되었다. 이는 빗물을 사용해야하는 시기에 저류조에 저류된 빗물의 양이 부족한 것과 운영비 부담 순으로 조사되었다. 따라서 빗물이용시설의 빗물이용활성화를 위해서는 물수요-공급에 대한 개념을 도입한 물수지 분석이 필요하며, 운영비 부담을 줄일 수 있는 다양한 방안을 탐색하는 것이 적절할 것이다. 현장조사 결과에서도 기술 등의 발달로 빗물이용시설은 잘 구축되고 있으나 활용처에서 필요한 필요수량에 따라 활용률이 상이한 것으로 조사되었다. 이러한 실태조사 및 현장조사를 바탕으로 빗물이용시설의 빗물이용 활성화를 위한 방안에 대하여 기술적 및 제도적 방안에 대해서 제안하였다.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.111-124
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• 2014

Decentralized water supply systems, treating the water in users'vicinity, cutting down the distribution system, utilizing the alternative water resources(rainwater harvesting, water reclamation and reuse and so on.) and saving energy and other resources, could be categorized into POU(Point-Of-Use), POE(Point-Of-Entry) and community small scale system. From the literature review, we could thought that decentralized water supply system and hybrid system(integrating centralized and decentralized water supply system within urban water management) might have strengthening comparative advantages to centralized system with respect to: (1) water security, (2) sustainability, (3) economical affordability. Even though it is difficult to derive and quantify direct benefit advantages from decentralized and hybrid system in comparison with centralized system, (1) operational cost reduction, (2) assurance for safe and stability water supply and (3) greenhouse gas reduction can be expected from successful establishment of the former.