• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.494-494
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• 2017

국내의 호소는 대부분이 농업용수 공급을 목적으로 설치된 인공 호소이다. 최근 이상기후 및 유역 오염원 증가로 호소의 수질오염도가 증가 추이에 있으며, 특히 하절기 외기온도 상승과 함께 녹조 대량발생, 어류 집단폐사 등 수질오염사고가 야기되고 있다. 이러한 수질오염사고는 호소의 지역적 특성으로 인한 여러 가지 원인이 있겠지만 직접적인 원인으로는 호소의 산소 고갈에 기인된다. 본 연구에서는 농업용 호소의 수온, DO, EC 등에 대한 일주기 및 계절적 동적변화를 규명하여 호소의 수질개선대책수립에 활용하고자 하였다. 연구대상 지구는 경기도 시흥시에 소재하고 있는 M 농업용 저수지이며, 2015년 6월 4일부터 9월 22일까지 수온, DO, EC을 측정할 수 있는 연속 자동측정장치를 설치하였고, 측정지점은 저수지 수심을 상(바닥층에서 1.5m 상부), 중(바닥층에서 1.0m 상부), 하(바닥층에서 0.5m 상부)로 구분하여 각각 측정하였다. 호소의 수온은 일주기로 수온성층 형성과 대류혼합이 반복되었으며, 상 하층간의 수온 차이가 평균 $1.4^{\circ}C$, 최대 $5.0^{\circ}C$의 차이를 보였다. 또한 강우가 발생한 이후에는 일시적으로 저수지 상 하 층간 수온 차이가 거의 없는 것으로 나타났는데, 이는 강우에 의한 수체의 수직혼합으로 저수지 전체의 물질순환에 영향을 미친 것으로 판단된다. 호내 DO 농도는 일(day) 주기 동안 농도변화가 크게 나타났으며, 여름철 무강우 기간에는 저수지 바닥층의 평균 DO 농도가 약 0.5mg/L로 거의 무산소 상태가 지속되는 것으로 관측되었다. DO는 기온이 낮아지거나 강수가 발생할 때 대류에 의한 수직혼합에 의해 간헐적으로 회복되다가 다시 고갈되는 현상이 반복되는 것으로 나타났다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.376-378
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• 2021

According to the 2020 Global Climate Report released by the World Meteorological Organization, the average temperature of the Earth in 2019 was measured 1.1℃ higher on average than the temperature measured between 1850 and 1900 before industrialization. The change in average temperature affects the distribution of plants, and according to the vulnerability analysis paper, it can be seen that there is a change in the distribution area of plants when the average temperature rises. In this paper, to cope with these environmental changes, we propose a method of fabricating intermittent flow hydroponic smart farms using Arduino and sensors and controlling them through PCs and applications. The manufactured hydroponic smart farm identifies the farm's temperature and humidity, positive pH concentration, illumination, and water quality to check the amount of pumping, supplement LED control, sensor condition, overall management and cultivation of the farm, and grows in an appropriate environment.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.45-53
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• 1999

The soil samples were measured at 90 sites of Soil's Network In 1997~1998 which was established for the investigation of soil contamination in Seoul. This study was more focused to measure and analyze for BTEX(Benzene, Toluene, Ethylbenzene and Xylene) concentration in the Soil Network. Also, the samples were analyzed by Purge & Trap method. As a result, the BTEX were detected at all sampling sites in Seoul. The Min. Max and Mean BTEX concentration were respectively 0.047mg/kg, 2.618mg/kg and 0.437mg/kg in 1998. The concentration of the BTEX detected at all sampling sites was lower than that of the intervention standards(at industrial areas) of Soil Preservation Act.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.49-55
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• 2016

Background: For the purpose of baseline data collection and enhancement of environmental monitoring the distribution studies of $^{137}Cs$ and $^{90}Sr$ in the soil of Uljin province was performed and the relation between surface soil activities and soil properties (pH, TOC and median of the surface soil) was analyzed. Materials and Methods: For 14 spots within 10 km from the NPP surface soil samples were collected and soils for depth profile were sampled for 3 spots in April 2011. Using ${\gamma}$-ray spectrometry with HPGe detector, the concentrations of $^{137}Cs$ were determined and the concentrations of $^{90}Sr$ were measured by counting ${\beta}$-activity of $^{90}Y$ (in equilibrium with $^{90}Sr$) in a gas flow proportional counter. Results and Discussion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ were $<0.479-39.6Bq{\cdot}(kg-dry)^{-1}$ (avg. $7.51Bq{\cdot}(kg-dry)^{-1}$) and $0.209-1.85Bq{\cdot}(kg-dry)^{-1}$ (avg. $0.74Bq{\cdot}(kg-dry)^{-1}$) which were similar to the reported values from other regions in Korea. The activity ratio of $^{137}Cs$ to $^{90}Sr$ in surface soils was around 9.67, which is much bigger than the initial value of 1.75 for worldwide fallouts because of faster downward movement of $^{90}Sr$ after fallout than that of $^{137}Cs$. For depth profile studies soils were collected down to 40 cm depth for the locations of Deokgu, Hujeong and Maehwa. The $^{137}Cs$ concentration distribution of the first two showed maximum values at top soils and decreased rapidly in exponential manner, while $^{90}Sr$ showed two local maximum values for soils near top and about 30 cm depth. Through linear fittings between the $^{137}Cs$ and $^{90}Sr$ concentrations of surface soil and pH, TOC and median of the surface soil, the only probable relationship obtained was between $^{137}Cs$ and TOC (determination coefficient $R^2=0.6$). Conclusion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ in Uljin were similar to the reported values from other regions in Korea. The only probable relationship obtained between activities and soil properties was between $^{137}Cs$ and TOC.

• Journal of Soil and Groundwater Environment
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• v.14 no.3
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• pp.32-39
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• 2009

This study was conducted in order to get the scientific background for soil pollution criteria. The 92 soil samples derived from various geological units were taken and analyzed to survey natural heavy metal background levels using aqua regia digestion method and 0.1N HCl extraction method. From these results, the average natural contents of metals were 0.287 mg/kg for Cd, 15.26 mg/kg for Cu, 18.43 mg/kg for Pb, 25.36 mg/kg for Cr, 54.27 mg/kg for Zn, 17.68 mg/kg for Ni, 6.83 mg/kg for As by the aqua regia method, and 0.040 mg/kg for Cd, 0.48 mg/kg for Cu, 3.06 mg/kg for Pb, 0.09 mg/kg for Cr, 1.54 mg/kg for Zn, 0.27 mg/kg for Ni, 0.089 mg/kg for As by the 0.1N HCl extraction method. Ratios of soluble contents and total contents were Cd 0.14, Cu 0.03, Pb 0.17, Cr 0.004, Zn 0.03, Ni 0.02, As 0.013 and the correlation coefficients of soluble contents and total contents were 0.24(As), 0.88(Cd), 0.43(Cr), 0.65(Cu), 0.70(Pb), 0.61(Ni), 0.24(Zn). The correlation factor decreased in the order of Cd > Pb > Cu > Ni > Cr > Zn $\approx$ As.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4335-4347
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• 2015

The objective of this study was to investigate $PM_{10}$ and $CO_2$ concentrations in the classrooms of 286 elementary schools in Suwon, Ansan, and Hwaseong in the province of Gyeonggi between August 2008 and December 2012. By gaining an understanding of the environmental factors that influence these concentrations, this study also aimed to establish a management plan for indoor air quality in schools, which substantially affects the health of elementary students. When the schools were classified by region, no statistically significant difference in $PM_{10}$ concentration was observed. However, $PM_{10}$ concentration was relatively high in industrial areas and low in rural areas. No difference in $CO_2$ concentration was observed among the surveyed cities. Analysis of annual $PM_{10}$ concentration showed that the highest values for Suwon and Hwaseong occurred in 2008 and 2009, respectively (p<0.01). In the case of Ansan, the highest concentration occurred during 2009, but the difference was not significant compared to the other years. Analysis of the annual $CO_2$ concentration of each city shows no significant difference among the cities (p-value=0.366,0.730,0.210). According to a time series analysis of $PM_{10}$ and $CO_2$ by season, from autumn 2008 to winter 2012, $PM_{10}$ concentration was high during 2009, then it gradually decreased until 2012, and started to increase again. While no difference in annual $CO_2$ concentration was observed, the concentration had a tendency to be higher in spring and winter than in summer. By analyzing the relationship between $PM_{10}$ and $CO_2$ and the environmental factors (years of construction, average students of classroom, temperature, and humidity), it showed a significant negative correlation was found between $CO_2$ and the environmental temperature and humidity, at -0.329 and -0.188, respectively (p<0.01).

• The Journal of Engineering Geology
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• v.3 no.3
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• pp.241-252
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• 1993

Lead bas been found in the groundwater in Door County, Wiscorsin, with temporally and spatially irregular distribution in concentration. Correlation coeffidents were calculated among lead indicators in groundwater(frequency of lead detections, mean and maximum concentration of lead detections) and seven independent variables(stucture and geographic factors of wells, hydrogeological factors at lead-arsenate mixing sites and the level of soil contamination) which are possibly related to the lead level in groundwater. The significance of relationships was determined statistically by a t-test at the 90% confidence level, and indicated that the spatially located lead-arsenate mixing sites provided the lead in groundwater in the study area. A total of 112 groundwater samples were collected from 5 house wells with previous lead detects. Lead was detected in partides on ifiter papers with $0.45{\;}\mu\textrm{m}$ pore size, but not in filtrates. The result of chemical analysis for lead indicates that lead is associated with partides in groundwater in Door County. Subsequently, the irregular distribution of lead in the county results from the transport of particulate lead along the advective groundwater movement through the preferential pathways sucn as vertical and bedding-plane joints.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.613-623
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• 2013

This study is purposed to evaluate the airborne asbestos concentrations in life environment surroundings in Seoul. In study, we investigated airborne asbestos concentrations in thirteen subway stations, four monitoring networks and each vicinity roadside, six stream surroundings, four tunnels quarterly and we also investigated relationship between the airborne asbestos concentrations and ambient temperature in monitoring networks and time-based airborne asbestos concentration variability for two typical monitoring networks, two subway stations transferred and used by lots of people through Phase Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM). The airborne asbestos concentrations by PCM for 4 objects of study were less than the detection limit (7 fiber/$mm^2$) in 111 (50%) out of 223 samples. The highest concentration was 0.0130 f/cc. But additional TEM analysis result for samples exceeding the guideline value for indoor air quality (0.01 f/cc) proposed by the Ministry of Environment (Korea), no asbestos was detected. Similarly TEM analysis result for 124 samples, no asbestos was detected. The average airborne asbestos concentrations by PCM in subway stations, monitoring networks, streams and tunnels were $0.0041{\pm}0.0027$ f/cc, $0.0015{\pm}0.0011$ f/cc, $0.0024{\pm}0.0012$ f/cc and $0.0016{\pm}0.0020$ f/cc. All objects of study were satisfied with the guideline value for indoor air quality. The relationship between the airborne asbestos concentrations and ambient temperature in monitoring networks was generally positive correlation (r = 0.660). The higher ambient temperature was and the more transient population was, the airborne asbestos concentrations by time for two subway stations were increased. While the airborne asbestos concentrations for two monitoring networks showed no variation pattern according to time.

• Korean Journal of Environmental Agriculture
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• v.5 no.1
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• pp.43-47
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• 1986

In order to evaluate the pollution potential of agricultural crops after the construction of Onsan Industrial Complex (non-ferrous metal refineries), concentrations of hazardous heavy metals were analyzed for crop samples (rice, barley, soybean, vegetables and fruits) grown near the Complex in 1978. Although a slight difference was found among the kinds, parts and growing regions of the crops, no definite tendency was observed. The mean/maximum concentrations of crop samples were 0.23/4.0ppm As, 0.4/1.2 ppm Cd, 4.88/12.7ppm Cu, 0.09/0.4 ppm Hg, 3.86/5.0 ppm Pb and 41.3/105 ppm Zn, which may serve as the natural background data for this region.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3740-3747
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• 2009

To protect the citizens' health of Gyeongju and to secure basic data for the assessment of health and environmental risk, distribution characteristics of meteorological elements were investigated and numerical simulation of wind field using RAMS model was carried out. In addition, measurement and analysis of air pollutants, forecasting the behavior air pollutants using ISC-AEROMOD view, and health and environmental risk-influenced zones were defined through managing air polluting materials to prevent health damage and property damage. According to the survey results of air pollution in Gyeongju and surroundings, average annual concentration of air pollutants in Gyeongju was slightly lower than that in Pohang and Ulsan areas, but concentration of particulate matters and nitrogen dioxide at Gyeongju Station Square and Yonggang Crossing were sometimes higher than that in Pohang and Ulsan areas. Results of the modeling of moving and diffusion of air pollutants that affect citizens' health showed that parts of the 1st through 4th industrial complexes together with POSCO were included in particulate matters and sulfur dioxide influenced areas in Pohang Steel Complex area, and that Haedo-dong, Sangdae-dong, Jecheol-dong and Jangheung-dong in Pohangnam-gu represented locally worsened air quality due to a quantity of air pollutant emission from dense steel industries and large scale industrial facilities.