• Journal of Wetlands Research
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• v.18 no.1
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• pp.10-15
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• 2016

In this research, the environmental effects of rain garden when applied to a stormwater runoff originated from a rooftop were evaluated. The rain garden that was utilized as LID represents less than 1% of the catchment area that it drains. Storm event monitoring was conducted from March 2012 to August 2014 on a total of 19 storm events. In the 19 storm events that was monitored only 32% produced an outflow which has a mean rainfall characteristic of approximately 25 mm. With the application of rain garden, hydrologic improvement was observed as the facility exhibit a delay and reduction in the production of runoff and peak flows as the rainfall progresses. Furthermore, in terms of pollutant reduction, it was observe that the rain garden showed a generally satisfactory performance in reducing pollutants. In addition to this, the rain garden also has additional attributes that adds to the aesthetic appeal of the surrounding environment as well as in the lives of the people. The findings of this research will help in the further improvement and reinforcement of LID designs.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.38-44
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• 2015

In Korea, most rainfall events occur during summer which then leads to an increasing concern regarding high influx of non-point source pollutants since the pollutant loadings from these non-point sources are very significant. In particular, the first flush of roof-harvested rainfall is said to contain the most highest concentration of nutrients and heavy metals. Accordingly, it is important to develope the possible water quality management options in treating the contaminants and considering reclaimed water reuse. The rain garden could be one of suitable alternatives in addressing this issue. In this study, the development of an effective adsorption media and its application to a lab-scale rain garden was tested to evaluate the removal rate of various nutrient and organic matter (TN, TP, CODcr), and heavy metals (Cu, Cd, Pb). Results showed that carbonized peatmoss produced at higher temperature have better adsorption capacity as compared to the one produced at a lower temperature. When the carbonized peatmoss was applied as rain garden media, the highest removal of TN, TP, and CODcr was observed compared to no carbonized peatmoss applied rain garden. Therefore, this study showed that the carbonized peatmoss would be effectively applied to the rain garden for removing nutrients and heavy metals from roof-harvested rainwater.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.481-487
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• 2016

In this research, a pilot scale hybrid rain garden system was developed in order to investigate the efficiency in the different components of the hybrid rain garden system and at the same time evaluate the initial efficiency of the system in treating urban stormwater runoff prior to its actual use in the field. Experimental runs were conducted using synthetic runoff having target concentrations similar to that of the typical runoff characteristics found in different countries and in Korea. With the employment of the hybrid rain garden system, hydrologic improvement was observed as the system demonstrates an approximately 95% reduction in the influent runoff volume with 80% retained in the system, and 15% recharged to groundwater. The reduction was contributed by the retention capabilities of ST and infiltration capabilities in PB and IT. With the combined mechanisms such as filtration-infiltration, biological uptake from plants and soil and phytoremediation that are incorporated in PB and IT, the system effectively reduces the amount of pollutant concentration wherein the initial mean removal efficiency for TSS is 87%, while an approximate mean removal efficiency of 76%, 46% and 56% was observed in terms of organics, nutrients and heavy metal, respectively. With these findings, the research helps in the further improvement, innovation and optimization of rain garden systems and other facilities as well.

• Journal of Wetlands Research
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• v.18 no.1
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• pp.24-31
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• 2016

The increase of impervious area in cities caused the unbalanced water cycle system and the accumulated various contaminants, which make troubles as introducing into watershed. In Korea, most of rainfall in a year precipitate in a summer season. This indicate that non-point source pollution control should be more important in summer and careful rainfall reuse strategy is necessary. Accordingly, the aim of this study is to monitor the characteristics of rainfall contaminants harvested in roofs and to develop the rainfall treatment system which are designed to fit well in a typical domestic household including rain garden. The rain garden consists of peatmoss, gravel and san to specially treat the initial rainfall contaminants. For this purpose, lab scale experiments with synthetic rainfall had been conducted to optimize the removal efficiency of TN, TP and CODcr. After lab scale experiments, field scale rainfall treatment system installed as a pilot scale in a field. This system has been monitored during June to July in 2015 in four time rainfall events as investigating the function of time, rainfall, and pollutant concentrations. As results, high loading of pollutants were introduced to the rainfall treatment system and its removal efficiency is increased as increase of pollutant concentrations. Since it is common that the mega-size of rainfall treatment system is not attractive in urban area, small scale rainfall treatment system is promising to treat the non-point source contaminants from cities. In addition, this small scale rainfall treatment system could have a potential to water resue system in islands, which usually suffer the shortage of water.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.100-109
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• 2016

Low impact development (LID) facilities are established for the purpose of restoring the natural hydrologic cycle as well as the removal of pollutants from stormwater runoff. Improved efficiency of LID facilities can be obtained through the optimized interaction of their major components (i.e., plant, soil, filter media, microorganisms, etc.). Therefore, this study was performed to evaluate the performances of LID facilities in terms of runoff and pollutant reduction and also to provide an optimal maintenance method. The monitoring was conducted on four LID technologies (e.g., bioretention, small wetlands, rain garden and tree box filter). The optimal SA/CA (facility surface area / catchment area) ratio for runoff reduction greater than 40% is determined to be 1 - 5%. Since runoff reduction affects the pollutant removal efficiency in LID facilities, SA/CA ratio is derived as an important factor in designing LID facilities. The LID facilities that are found to be effective in reducing stormwater runoff are in the following order: rain garden > tree box filter > bioretention> small wetland. Meanwhile, in terms of removal of particulate matter (TSS), the effectiveness of the facilities are in the following order: rain garden > tree box filter > small wetland > bioretention; rain gardens > tree box filter > bioretention > small wetland were determined for the removal of organic matter (COD, TOC), nutrients (TN, TP) and heavy metals (Cu, Pb, Cd, Zn). These results can be used as an important material for the design of LID facilities in runoff volume and pollutant reduction.

• Land and Housing Review
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• v.2 no.4
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• pp.503-507
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• 2011

There was a plan to develop a low-carbon green village(approximately $400,000m^2$) in A city, a new town. Restoration of water cycle is essential for creation of the low-carbon green village. Therefore, installation plan of LID-decentralized rainwater management facilities for natural water cycle was established for creation of the low-carbon green village. Analyses on effect of the water cycle were performed in conditions of before, after developing the low-carbon green village and after installing the LID facilities(rain garden, constructed wetland, rainwater harvesting facility, etc.) using SWMM-LID model developed by EPA. Due to the characteristic of permeable area before development and significant green spaces after development, installation plan of LID facilities to restore the water cycle did not show an obvious effect. However, potential of the hydrological cycle could be seen by the installation of the LID facilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.3
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• pp.333-342
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• 2022

Due to climate change, increased heavy rainfalls result in flood damage every year. To investigate the storm-runoff reduction effects of Low Impact Development (LID), this study performed runoff analyses using the U.S. Environmental Protection Agency (EPA) Storm Water Management Model (SWMM) for past and future representative storm events of the Yongdu Rainwater Pumping Station basin. As a result, the infiltration loss for representative future rainfalls increased by 3.17 %, and the surface runoff and peak runoff rate increased significantly by 32.50 %, and 128.77 %, respectively. To reduce the increased surface runoff and peak runoff rates, this study investigated the applicability of LID approaches, including a permeable pavement, green roof, and rain garden, by adjusting the LID parameters and the ratio of installation area. We identified the ranges of LID parameters that decreased peak runoff rate and surface runoff, and increased infiltration. In addition, when the application ratio of permeable pavement, green roof, and rain garden was 2:1:3, best performance was attained, leading to a reduction of peak runoff of 26.85 %, infiltration loss 12.01 %, surface runoff 15.11 %, and storage 509.47 %. Based on analyzing the effect of storm runoff reductions for various return periods, it was found that as the return period increased, the proportion of peak runoff and surface runoff increased and the proportion of infiltration loss and storage decreased.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.444-444
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• 2015

현제 도시유역의 산업화와 도시화로 인해 유역 내 불투수면적의 증가는 직접 유출량 증가, 지하수자원 고갈, 침투량 감소, 증발산량의 감소 등의 물 순환 체계의 변화를 가져왔다. 이러한 도시 유역 내 물 순환 체계 변화를 개선하기 위해 여러 국가에서 저영향개발(Low Impact Development, LID)의 개발 및 도입이 진행되고 있다. LID는 분산형 빗물관리 시설로써 유역 내 소규모의 LID 요소기술을 대상유역에 적용하여 강우유출수를 저류, 체류, 방지 및 처리하는 시설을 의미한다. LID는 궁극적 목표로 계획단계에서 개발이전의 수문기능을 유지하기 위해 보전, 영향최소화, 유출이동시간 유지, 추가유출량 감소, 오염발지에 초점을 맞추어 계획된다. 현제 LID의 성능 및 적용성에 대한 다양한 연구가 진해되어지고 있으나, LID 요소기술별 시공 비용, 유지관리 비용, 강우유출수 저감효율, 비점오염원 저감효율, 적용위치 등의 다양한 인자를 복합적으로 고려하여 LID요소기술별 적용성 평가를 수행한 연구는 미미한 실정이다. 따라서 본 연구에서는 LID 요소기술 중 나무화분 여과장치, 옥상녹화, 빗무정원, 투수성포장, 침투트렌치, 빗물통, 식생수로 등의 총 7가지 LID 요소기술을 대상으로 연구를 수행하였다. LID 요소기술의 적용성평가를 수행하기 위해 시공비용, 유지관리비용, 강우유출수 저감효율, 비점오염원 저감효율, 적용위치 등의 촐 5가지 평가인자를 Entropy 방법을 이용하여 평가인자별 가중치를 산정하였다. 이후 다기준의사결정 방법 중 PROMETHEE 방법을 이용하여 LID 요소기술의 우선순위를 산정하였다. 현제 PROMETHEE 방법을 이용하여 LID 요소기술별 우선순위를 산정한 결과 옥상녹화가 첫번째 우선순위로 분석되었으며, 침투트렌치, 나무화분여과장치, 투수성포장, 식생수로, 빗물통, 빗물정원 순으로 분석되었다. 따라서 국내에 LID를 적용할 경우 옥상녹화, 침투트렌치, 나무화분 여과 장치 등의 LID 요소기술의 적용성 및 기대효과가 클 것으로 판단된다. 그러나 국내의 모든 지역을 대상으로 적용하기에는 문제가 있으며, 국내 LID 요소기술 적용 시 기초자료로 사용될 수 있을 것으로 판단된다. 대상지역별 신뢰도 높은 LID 요소기술 적용성 평가를 위해서는 대상유역 내 시공된 LID 요소기술을 계측하여 비점오염원 및 우수유출수 저감효율, 시공 비용, 연간 유지관리 비용을 분석하여 평가를 수행되어 한다고 판단된다.

• Journal of Environmental Impact Assessment
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• v.31 no.2
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• pp.117-127
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• 2022

The survey of bird community characteristics was carried out four times on 2016 and 2017, respectively May and October to figure out effects of the manmade small ecosystem, Anseong. Twenty five species and 94 individuals were observed in the study area. The dominant species were Passer montanus 19.1%, Pica pica 12.8%, Cyanopica cyana 8.51%, Sinosuthora webbiana and Carduelis sinica ussuriensis respectively 7.45%, the diversity of the species was 2.787. With migration, the highest number and percentage to the lowest was residents 72.0%, summer visitors 20.0% and winter visitors 8.00%. Among 22 species which bred (check or possibility) in the manmade small ecology, Anseong, canopy (C) was 54.5%, hole (H) was 31.8%, bush (B) was 9.09% and ground (G) was 4.55% in their nesting guilds. In foraging guilds in breeding season was canopy (C) was 69.6%, bush (C) was 21.7%, water (W) and ground (G) was respectively 4.35%, and in non-breeding season, canopy was 64.0%, bush 24.0%, ground was 8.00% and water 4.00%. In the study site, the manmade habitats for birds were nest box and wetland (rain garden). In 7 nest box, Parus major was uesd 1 nest box as their breeding on 2016 and 2017, and Passer montanus was used 1 nest box on 2017. We assumed that sustainable rainwater supply may be important to attract many birds in rain garden, the manmade habitat for birds.Unfortunately, however, no birds used rain garden (wetland) as their habitats due to water shortage.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.468-468
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• 2022

기후변화 및 도시열섬화 등의 영향으로 여름철 폭염 및 봄·겨울철 미세먼지 영향은 증가하고 있다. 최근 40년(1980년~2019년) 동안 서울의 최고기온은 2.2℃ 증가하였으며, 이는 전국에서 두 번째로 높은 증가추세이다. 서울시는 도시열섬과 미세먼지 저감을 일환으로 '스마트 물순환도시 조성사업'을 추진하고 있다. 본 연구에서는 서울형 물순환도시 소개와 더불어 쿨링포그, 쿨루프, 클린로드시스템, 투수블록, 식생수로 빗물정원 등 수자원을 활용한 기술을 조사하고 문헌조사를 통해 저감효과를 비교분석하였다. 이는 수자원을 활용한 도시 형태 개선으로 쾌적한 도시환경 조성 뿐만 아니라 시민의 행복과 만족감 증대에 기여할 것으로 판단되며, 향후 서울형 스마트 물순환도시 보다 많은 지역에 확대운영 할 수 되도록 기여하고자 한다.