• Advances in environmental research
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• 제2권4호
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• pp.279-290
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• 2013

In this study, a comprehensive model developed to estimate greenhouse gas (GHG) emissions from urban area with low impact development (LID) and its integrated management practices (IMPs). The model was applied to the actual urban area in Asan Tangjeong district (ATD) as a case study. A rainwater tank (1200 ton) among various LID IMPs generated the highest amount of GHG emissions ($3.77{\times}10^5kgCO_2eq$) and led to the utmost reducing effect ($1.49{\times}10^3kgCO_2eq/year$). In the urban area with LID IMPs, annually $1.95{\times}104kgCO_2eq$ of avoided GHG emissions were generated by a reducing effect (e.g., tap water substitution and vegetation $CO_2$ absorption) for a payback period of 162 years. A sensitivity analysis was carried out to quantitatively evaluate the significance of the factors on the overall GHG emissions in ATD, and suggested to plant alternative vegetation on LID IMPs.

• 한국환경복원기술학회지
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• 제24권6호
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• pp.109-119
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• 2021

Thermal environment of city is getting worse due to severe urban heat island caused by climate change and urbanization. Green roof improves the urban thermal environment and save the cooling energy in buildings. This study presented a green roof combined with a storage system that stores rain-water and supplies water through a wick and evaluated the temperature reduction effect as surface temperature and amount of evapotranspiration. For about a week, the surface temperature using a infrared thermal imager and the evapotranspiration by recording change of module weight were measured at intervals of 30 minutes from sunrise to sunset. The results show that the mean surface temperature of the green roof was 15.4 degrees lower than that of the non-green roof from 12:00 P.M. to 14:00 P.M. There was no significant difference between mean surface temperature of green roof with and without storage system immediately after rain, but more than a week after rain, there was a difference with average of 2.49 degrees and maximum of 4.72 degrees. The difference in daily amount of evapotranspiration was measured to be 1.66 times on average. As drought stress increased over time, the difference in daily amount of evapotranspiration and surface temperature between with/without storage system increased simultaneously. The results of the study show a more excellent cooling effect of green roof combined with the rainwater storage system.

• 상하수도학회지
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• 제23권6호
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• pp.719-726
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• 2009

One of the alternative runoff management measures is on-site runoff mitigation, such as rainwater retention tank and infiltration facilities especially the latter that is possible to manage simultaneously runoff quality and quantity as a perspective of water-cycle. This study was conducted to develop a particle separator, inclined-pipe settling system, that could improve particle removal efficiency of road runoff as a pre-treatment device of stormwater infiltration. Solid particles larger than $100{\mu}m$ are separated by simple sedimentation; however, the significant amount of pollutants with a diameter less than $100{\mu}m$ remain in suspension. Without any treatment in that case of the runoff into infiltrate, groundwater would be deteriorated and also infiltration rate would be decreased by clogging. Therefore, we suggest optimal design parameters (inclined angle, pipe length, and surface loading rate) of inclined-pipe settling system which can be designed to effectively remove particles diameter smaller then $70{\mu}m$. Thus, the results showed TSS removal efficiency more than 80% with a particle diameter between $20{\mu}m$ and $70{\mu}m$, 100% above particle diameter $70{\mu}m$ for the inflow rate $0.018 m^3/m^2{\cdot}hr$ with pipe inclined at angle $15^{\circ}$.

• 조명전기설비학회논문지
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• 제23권1호
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• pp.92-99
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• 2009

심매설 접지봉의 경우 장마철에 빗물이나 지하수와 접촉하는 경우가 발생한다. 수중에 잠겨있는 접지극에 서지 전압이 인가되면 접지극 주변에서 이온화 현상이 발생하게 된다. 지중이나 수중에서의 이온화 현상은 접지 시스템의 에너지적인 특성에 의해 영향을 받는다. 이 논문의 목적은 축소된 전해 수조를 이용하여 임펄스 전압에 의한 접지시스템의 과도특성을 파악하는데 있다. 매틀랩 프로그램을 활용하여 이온화에 의한 전위저감과 방출된 에너지를 측정하여 정량적인 분석을 수행하였다. 접지극 끝단의 최대 전압은 물의 저항률과 Marx형 전압발생장치의 충전전압에 따라 다양하게 나타났다. 접지극 끝단의 전위는 절연파괴전압에 이르기 전 인가전압에서 대략 절반까지 감소하였다. 또한 절연파괴가 발생하기 전 인가된 에너지의 절반 이상의 에너지가 이온화에 의해 접지극을 통하여 방출되었다.

• 한국환경과학회지
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• 제22권5호
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• pp.639-649
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• 2013

Over 96.2% of the agricultural water in Jeju Island is obtained from groundwater and there are quite distinct characteristics of agricultural water demand/supply spatially because of regional and seasonal differences in cropping system and rainfall amount. Land use for cultivating crops is expected to decrease 7.4% (4,215 ha) in 2020 compared to 2010, while market garden including various vegetable crop types having high water demand is increasing over the Island, especially western area having lower rainfall amount compared to southern area. On the other hand, land use for fruit including citrus and mandarin having low water demand is widely distributed over southern and northern part having higher rainfall amount. The agricultural water demand of $1,214{\times}10^3\;m^3/day$ in 2020 is estimated about 1.39 times compared to groundwater supply capacity of $874{\times}10^3\;m^3/day$ in 2010 with 42.4% of eastern, 103.1% of western, 61.9% of southern, and 77.0% of northern region. Moreover, net secured amount of agricultural groundwater would be expected to be much smaller due to regional disparity of water demand/supply, the lack of linkage system between the agricultural water supply facilities, and high percentage of private wells. Therefore, it is necessary to ensure the total net secured amount of agricultural groundwater to overcome the expected regional discrepancy of water demand and supply by establishing policy alternative of regional water supply plan over the Island, including linkage system between wells, water tank enlargement, private wells maintenance and public wells development, and continuous enlargement of rainwater utilization facilities.

• 한국지역지리학회지
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• 제19권4호
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• pp.615-626
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• 2013

연구는 최근 5년간(2006~2010) 서울시 행정동 단위별로 도시 홍수를 유발하는 기후요인, 홍수에 노출된 정도를 나타내는 민감도, 홍수피해를 저감하는 능력을 나타내는 적응도 요소들을 종합한 서울 도심지역의 홍수 취약도 지수의 공간적 분포 특징을 밝히고자 하였다. IPCC(Intergovernmental Panel on Climate Change) 취약성 모델에 기반을 둔 상관성 분석 결과 서울 도심의 홍수피해 건수는 여러 홍수취약성 관련 변수 중 빗물저류조 용량, 1일 최대강우량, 빗물펌프장 토출량 등과 높은 상관관계를 갖는 것으로 나타났다. 서울 도심지역의 홍수 취약도 공간분포도를 분석한 결과 안양천과 중랑천 등 도심하천 주변의 광범위한 행정동 지역에서는 공통적으로 높은 민감도가 홍수 취약도를 높이는 주요 요인임을 알 수 있었다. 특히, 중랑천 주변지역은 높은 민감도 이외에도 높은 기후요인에 의해 홍수 취약도가 높게 나타남을 알 수 있다. 국지적으로 홍수 취약성이 높게 나타난 강동구와 송파구 일부 행정동 지역에서는 적응도가 낮아 홍수 취약도가 높게 나타났고, 강남구 일부 행정동 지역에서는 극한강수현상과 같은 기후요인과 민감도가 높아 홍수 취약도가 상대적으로 높게 나타나고 있다. 이러한 고해상도 행정구역인 행정동 단위에서 도출된 홍수 취약성 분포도는 도심 내부의 지역별 적합한 홍수 대응, 관리 및 예방 정책을 수립하는 데 유용한 기초자료로 활용될 수 있을 것으로 예상된다.