• Korean Journal of Environmental Agriculture
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• v.26 no.2
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• pp.116-123
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• 2007

This experiment was conducted to investigate the distribution and burden characteristics of heavy metals in the rainwater sampled at Suwon area, in the middle part of Korea, from April 2002 to October 2003. The relationship between concentration of heavy metal and other chemical properties in the rainwater was also evaluated. Chemical properties in the rainwater were various differences with raining periods and years. It appeared that a weighted average pH of rainwater was ranged from 4.7 to 5.5. Heavy metal concentrations in the rainwater were ranked as Zn>Pb>Cu>Ni>Cr>As>Cd. As compared with heavy metal concentrations of rainwater in 2002, Cd, Cu and As were higher than other element in 2003. There were positive correlation between major ionic components, such as Ca, Mg, and K, and heavy metal concentrations of rainwater, and As, CU, Cu, Zn and Ni were relatively higher relationship than Pb and Cr in respective to correlation coefficient. For heavy metal distribution of rainwater, the order of average enrichment factors was Cd>Pb>AS>Cu>Zn>Ni>Cr, and these were relatively higher than the natural component such as Fe, Mg and Ca. The monthly enrichment factors were relatively high in the spring (from April to May) at Suwon. The monthly amount of heavy metal precipitation was high in the rainy season from June to August because of great influence of rainfall.

• 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 Soil and Groundwater Environment
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• v.6 no.3
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• pp.73-91
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• 2001

compounds (VOCs) were selected for assessment of VOCs contamination in some urban runoff and groundwater samples in Seoul. They included 3 aromatic hydrocarbons, 13 alkyl benzenes, 1 ether, 26 halogenated alkanes, 10 halogenated alkenes, and 9 halogenated aromatics. The levels of VOCs in urban runoff and groundwater were measured for samples collected in March 2000, June 2000 and November 2000 in Seoul City. A total of 78 samples (44 run-off water, 27 groundwater, and 7 samples from 4 urban wastewater treatment plants in Seoul) were collected and analysed by GC-MS with purge and trap. After examination of the runoff, it was concluded that alkyl benzenes and aromatic hydrocarbons were organic compounds which were significantly impacted by traffic flows in Seoul. Of 62 VOCs, only 11 VOCs were not detected in runoff samples, while 14 VOCs were detected in 27 groundwater samples. The toluene content in the runoff was extremely variable from 0.1ppb to 29,310ppb, depending on the different sampling sites. The concentrations of xylene ranged between 0.07ppb and 2970ppb in the runoff. The concentrations ranged from 0.05ppb to 33.0ppb for benzene, 0.05ppb to 960ppb for ethylbenzene, 0.08ppb to 20ppb for trichloromethane (chloroform) , 0.03ppb to 4.30ppb for trichloroethylene(TCE) and 0.1ppb to 50ppb for 1,1,2-trichloroethane. From the preliminary study of groundwater from some wells in Seoul, the most frequently detected VOCs are djchlorornethane(methylene chloride), trichloromethane(chloroform) and toluene. Most of aromatic hydrocarbons, alkyl benzenes and other solvents generally lower than detection limits.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.151-155
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• 2007

The issue of acid precipitation and related environmental problems in East Asia have been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during crop cultivation season from April to October were investigated at Suwon, Korea. Also, to estimate the contribution of ions on its acidity, ion composition characteristics and neutralization effects by cation ions were determined. Ion balance and electrical conductivity balance between the measured and estimated values showed high correlation. Rainwater had distributed highly in the range of pH 4.5~5.6. The pH of rainwater was relatively high at June as compared with other monitoring periods. $Na^+$ was the main cation followed by $NH_4{^+}$, $Ca^{2+}$, $H^+$ > $K^+$ > $Mg^{2+}$. Among these, $Na^+$, $NH_4{^+}$, $Ca^{2+}$ and $H^+$ covered over 93% of total cations. About 86% of anion in rainwater was composed of $SO{_4}^{2-}$ and $NO_3{^-}$. In rainwater samples, $NH_4{^+}$ and $Ca^{2+}$ contributed greatly to neutralization of the rain acidity. Also, 88% of soluble sulfate in rainwater was nss-$SO{_4}^{2-}$(non-sea salt sulfate).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.387-397
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• 2021

Most of Korea's agricultural water is supplied by reservoirs, so dependence on them is very high. Accordingly, it is important to reduce this dependence and provide a stable agricultural water supply by utilizing an applicable alternative water source. Therefore, in this work, scenarios for different land uses were constructed, and an optimal water supply plan using rainwater and reused sewage water - which are alternative water sources - was created. A study was also conducted to determine the optimal capacity of a rainwater facility. From the analysis, a stable water supply was achieved in the scenario of maximum utilization of rainwater by changing an existing paddy area to a greenhouse area, and about 0.82 ton of flow capacity was required for 1 mm of rainfall on farms utilizing rainwater. As a result of analyzing the optimal scenario to derive the ratio of the storage capacity per unit water collection area, the rainwater storage capacity determined through MODSIM and the storage capacity determined through actual monitoring showed similar results, about 31 and 32 %, respectively, and the optimal capacity of rainwater facilities was calculated to be about 5,796,000-6,182,400 ton.

• Korean Journal of Remote Sensing
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• v.36 no.6_3
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• pp.1733-1741
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• 2020

This study analyzed the effect of meteorological factors on the concentration of PM10 (particulate matter 10) in the atmosphere and the variation of rainwater quality using multivariate statistical analysis. The concentration of PM10 in the atmosphere was continuously measured during eleven precipitation events with a custom-built PM sensor node. A total of 183 rainwater samples were analyzed for pH, EC (electrical conductivity), and water-soluble cations (Na+, Mg2+, K+, Ca2+, NH4+) and anions (Cl-, NO3-, SO42-). The data has been analyzed using two multivariate statistical techniques (principal component analysis, PCA, and Pearson correlation analysis) to identify relationships among PM10 concentrations in the atmosphere, meteorological factors, and rainwater quality factors. When the rainfall intensity was relatively strong (> 5 mm/h, rainfall type 1), the PM10 concentration in the atmosphere showed a negative correlation (r = -0.55, p < 0.05) with cumulative rainfall. The PM10 concentration increased the concentration of water-soluble ions (r = 0.25) and EC (r = 0.4), and decreased the pH (r = -0.7) of rainwater samples. However, for rainfall type 2 (< 5 mm/h), there was no negative correlation between the PM10 concentration in the atmosphere and cumulative rainfall and no statistically significant correlation between the PM10 concentration in the atmosphere and rainwater quality.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.519-523
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• 2006

간선도로의 유입부 설계에는 도로 표면에 떨어진 강우만을 고려하여 빗물받이 간격, 형태 등을 결정하고 있으나, 현실적으로는 간선도로와 연결된 소규모 도로에서 횡유입부로 유입되지 않는 유량이 간선도로의 침수를 가중시키고 있는 실정이다. 이러한 점들을 고려할 때, 침수피해에 의한 시민들의 재산을 보호하고 불편을 덜어주기 위해 소규모 도로의 합리적인 배수시설이 필요하며, 이런 배수시설로 부각되는 횡유입부의 차집효율을 분석할 필요가 있다. 본 연구에서는 횡유입부의 설계 실태를 조사하고, 현장조사를 실시하여 수리인자들을 실측하여, 실험장치의 제작과 효율적인 실험조건을 선정하였다. 도로에서 횡방향으로 설치되어 있는 빗물받이 유입구의 규모에 따른 가능 최대 차집유량과 그에 따른 효율을 분석하기 위하여 도로 종경사$(2{\sim}11.5%)$, 유량$(1.5{\sim}24{\ell}/sec)$, 빗물받이 유입구의 규모 및 형태(TYPEⅠ, TYPEⅡ)를 변화시키면서 실험을 실시하였다. 실측 자료를 분석한 결과, 도로의 종경사가 6%이상이 되면, 횡유입부의 차집효율이 급히 감소되는 것을 알 수 있었으며, 빗물받이 유입구 TYPEⅠ의 형태가 TYPEⅡ의 경우보다 차집효율이 현저하게 감소하고 있음을 알 수 있었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.422-422
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• 2011

지난 2010년 9월 21일 서울을 비롯한 우리나라 중부지역에 급습한 집중호우로 인하여 저지대 및 지하 공간 등에 상당한 홍수피해가 발생하였다. 이는 도심지역의 기존 수방대책의 한계점을 절실히 드러낸 호우사상으로 향후 극한 강우에 대비한 대응책 마련이 시급할 것으로 판단되며, 이러한 도심지역의 집중호우에 의한 홍수피해를 미연에 방지하기 위한 구조적 대책으로 저류조 설치를 고려해 볼 수 있다. 본 연구에서는 도심지역에 시공이 간편하며 유지관리가 편하고 공사비가 저렴한 PN(Plastic Nodular) 빗물저류조를 설치하였을 경우 타 공법에 비하여 장점으로 부각될 수 있는 효과와 집중호우시 우수저감 효과를 분석하였다. 분석결과 PN 빗물저류조 설치시 상부 토지이용계획이 가능하며 사업비의 절감과 악취, 해충발생에 따른 민원 및 안전사고 등의 문제점이 해소 되는 것으로 분석되었다. 또한 호우시에는 방재 기능과 갈수기에는 부족수량을 대체 이용할 수 있으며 평상시 저류조 상부는 근린공원과 체육시설 및 별도의 부족한 차량의 주차장 공간 등으로 이용 가능효과가 있는 것으로 분석되었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.3
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• pp.107-118
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• 1993

Continuous increasing of impervious area due to urbanization and rainfall quantity due to environmental changes aggravate flooding risk in low land area. Therefore. Seoul municipal authorities go on securing an ample budget for reinforcement and establishment of inner water and inland drainage pumping facilities. But. there is no investment for developing optimal operation rules for appropriate application of existing facilities. In this study. fuzzy control techniques are developed. and applied to 57 stations of inner water and inland drainage pump for model assessment. In these results. fuzzy models have more efficiency in the inland flooding protection than the existing pump operation rule by water level in the same conditions.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.130-133
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• 2016

The increase in impervious surfaces due to urban development has caused a groundwater drawdown through the reduction of underground infiltration, flood disaster due to increased rainfall runoff and environmental pollution in higher pollutant concentrations of first flush rainwater. As an alternative to these problems, the needs of low impact development (LID) techniques is increasing in urban areas. In this study, the restoration efficiency of water cycle was assessed at a residential site development applied with the LID rainwater management system. The results of monitoring the water cycling showed that the efficiency of water cycle of LID rainwater management system was improved 41% more than that of conventional methods.