• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.262-262
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• 2017

새만금 유역의 농업비점오염원은 총수질오염원의 68%로 많은 비중을 차지하고 있다. 이는 새만금 유역의 농업비점오염원을 제어하지 못하면 새만금 담수호의 수질에 악영향을 미친다는 의미이다. 또한, 국내 논 용수 이용량은 국가수자원 총 이용량의 40.5%으로 많은 비중을 차지하고 있다. 이에 따라서 논 배출수의 수량 및 수질관리가 농촌 비점오염 물질 관리에 매우 중요하다. 현재 많은 연구자들이 농촌 비점오염 물질을 저감하기 위하여 다양한 최적관리기법에 대한 실험을 실시하였다. 그러나 대부분 시험포를 조성하고 제한된 실험조건에서 효과를 검증한 연구 결과로 실제 농민에게 최적관리기법을 보급하여 그 효과를 검증한 연구는 미흡한 실정이다. 따라서 본 연구에서는 새만금유역 내 논에서 실제 영농활동을 실시하고 있는 농민들에게 최적관리기법 중 하나인 물꼬장치를 보급하고 물꼬 높이를 조절하게 함으로써 농민 스스로 비점오염물질을 저감 할 수 있도록 장려하였다. 연구 대상지점은 전라북도 부안군 백산면 용계리 일대 논이며, 연구 기간은 5월부터 9월까지로 영농 활동기를 대상으로 모니터링을 실시하였다. 물꼬 높이 조절은 중간낙수기 이전은 7 cm, 중간낙수 이후와 비영농기에는 물꼬 높이를 12 cm로 높여서 유지하도록 하였다. 농민 스스로 물꼬 높이를 조절하여 비점오염물질을 저감할 수 있도록 물꼬 보급 이후 정기적으로 교육을 실시하였다. 이후 영농 활동기별 유출량을 비교한 결과 관행 대비 평시 14%, 써레질 및 이앙기 3%, 강우시 15%, 중간낙수 기간에는 11%, 완전 물떼기 기간에는 10%의 저감효과가 있는 것으로 나타났다. 그러나 각 필지별 농도 및 오염부하 비교 결과 배수물꼬 적용에 따라 통계적으로 유의한 결과를 나타내지는 않았다. 배수물꼬 장치를 설치할 경우 유출량을 저감에는 큰 효과가 있었으나 농도를 줄이는데 에는 한계가 있는 것으로 나타났다. 하지만 본 연구 결과는 2016년 1년간의 짧은 연구기간동안의 자료이므로 추가적인 장기모니터링 연구를 통해 더 많은 자료구축이 필요하다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.628-628
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• 2015

유역의 형상은 강우, 산사태 등과 같은 지배적인 침식작용과 더불어 지형 지질학적 요인들에 의해 결정되어 진다. 그러므로 유역형상에 대한 공간특성 분석을 위해서는 지형학적 요인과 다양한 침식작용에 대한 분석이 필요하다. 국내 외 많은 연구결과에 의하면 지형학적 인자에 의한 침식 형태는 국부경사와 집수면적의 크기에 의해 다양한 구간으로 나뉘며, 그 특성에 따라 지표침식, 세굴, 산사태 등으로 구분되는 것으로 연구된 바 있다. 일례로 유역 내 세굴과 관련된 지배인자는 집수면적보다는 국부경사에 반대로 지표침식, 산사태는 국부경사보다는 집수면적의 크기에 따라 영향을 받는다. 따라서 지형학적 인자(국부경사, 집수면적)의 임계치(threshold) 산출을 통해 침식특성(불안정지역)을 검토할 수 있으며, 이에 대한 물리적 검증은 여러 연구를 통해 물질플럭스(유량, 에너지)에 대한 Power Law로써 검증된바 있다. 본 연구에서는 이러한 지형학적 침식특성 분석을 위하여 2006년 집중호우에 의해 광역적 산사태가 발생한 강원도 평창군 진부면 일대의 $10m{\times}10m$ DEM로부터 국부경사, 집수면적을 산출하고 경사-면적한계곡선(Slope-Area Threshold Curve, SATC), 배수면적 확률분포곡선(Probability distribution of Drain Areas Curve, PDAC), 에너지지수 확률분포곡선(Probability distribution of Energy Index Curve, PEIC)를 실제 산사태지점과 중첩하여 도시하였다. 그 결과, 특정 임계구간(Threshold Area, Unstable area, 2~3권역)내에서 산사태 발생지점이 분포하는 것으로 분석되었다. 이를 통해 지형학적 인자만을 고려하여 미계측 유역에 대한 잠재적 불안정지역의 판별이 가능할 것으로 판단되며, 추후 광역적 사면안정해석에 적용 가능할 것으로 판단된다.

• Journal of the Korean GEO-environmental Society
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• v.24 no.10
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• pp.33-39
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• 2023

As interest in the use of underground spaces increases, safety against water pressure acting on underground structures is required. In Korea, various buoyancy prevention methods are used to control such underground water pressure, and among them, the vertical drainage method with excellent economic efficiency, constructionability and stability has recently been introduced and applied. However, in the case of the vertical drainage method designed and constructed in the field, it is often designed and constructed depending on numerical analysis, making it difficult to expect practical stability judgment. Accordingly, in this study, an experiment was conducted to measure both pressure by installing a vertical drainage system using a model soil. Based on the measured value by the experiment and the numerical analysis value, we intend to compare and analyze the action positive pressure and use it as basic data for field application.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.412-412
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• 2023

정부는 2027년까지 식량자급률 55.4%를 달성하고, 채소·과실류 국내 공급 여력의 85% 수준을 유지하기 위한 적정 농지면적 150.0만ha가 필요하다고 추정하였다. 그리고 정부는 적정 면적 확보를 위해서 농지보전 목표가 포함된 중장기 기본계획을 수립할 예정이다. 이러한 식량자급률 달성과 채소 및 과실류 재배 면적 확보를 위해서는 논의 다각적인 활용 방안을 모색할 필요가 있다. 왜냐하면 최근 쌀 공급과잉 문제를 해결하기 위해 최근 '양곡관리법'이 정치적 이슈로 등장할 만큼 쌀 공급과잉 해소와 논 농지의 효율적인 활용에 대해 사회적 관심이 많다. 이러한 맥락에서 본 연구에서는 우리나라 최초로 논 배수 개선을 위해 지하암거가 설치된 경북상주시 공검면 일대를 대상으로 암거배수의 성과를 살펴보고 개선방안을 모색하였다. 이를 위해 본 연구에서는 지하암거 설치로 배수여건이 개선된 수혜농가 42명을 대상으로 심층면담을 실시하였다. 사례지역은 오태저수지를 기점으로 시작하는 공검소하천 양안에 넓게 위치하고 분지지형으로 하천보다 낮은 저지대로, 평상시·강수시 지하수위가 높아 습답이 형성되어 영농기계 사용이 어렵고, 일부지역의 경우 작물 파종, 수확을 하지 못하는 등 피해 발생하여 영농여건이 매우 불리한 지역이다. 이러한 배수불량을 개선하기 위해 수혜면적 55.6ha에 (지하)배수가 정비되었다. 이러한 배수 개선이 지역 영농에 미치는 효과는 다음과 같이 분석되었다. 첫째, 수혜구역 내 농가들은 배수불량으로 농기계 작업이 불편하고, 논의 습답을 제거하기 위해 해당 시설에 대한 필요성을 느끼고 있다. 또한 암거배수 시설로 인해 약 72% 농가들은 습답 개선의 효과가 있는 것으로 나타났다. 둘째, 전체 수혜농가의 약 72%는 암거시설로 인해 논의 습답이 개선된 것으로 나타났다. 특히, 암거시설로 인해 물빠짐이 개선되었고, 농기계 작업이 용이하게 되었다. 다만 사업 첫해에는 논을 파헤쳐 농기계가 빠지는 피해가 있었지만, 2차년도부터는 논이 정비되어 농기계 빠지는 피해는 없는 것으로 분석되었다. 셋째, 수혜 농가들이 느끼는 "습답 피해가 매우 있음"은 사업 시행 전 51.61%에서 사업 완료 후에는 4.17%로 급격히 감소하였다. 또한 "습답 피해가 전혀 없음"을 느끼는 농가는 사업 시행 전 3.23%에 불과했지만, 사업 완료 후에는 20.83%로 급증하였다.

• Journal of Korean Society of Rural Planning
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• v.28 no.4
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• pp.127-138
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• 2022

In responding to climate change in the agricultural sector, Climate Smart Agriculture (CSA) is an approach to establish a sustainable agricultural system through comprehensive management of technology, policy, and investment. The international community is continually expanding CSA implementation, and it became more important to understand the status of the domestic agriculture system and practices that are relevant to CSA. This study explored the available CSA in domestic agricultural systems and presented the order of relative importance of CSA technology. AHP analysis is employed for the evaluation with the following criteria: productivity, marketability, adaptability, and mitigation. The relative importance is evaluated with six agricultural technologies (soil, crop management, water, energy efficiency, alternative energy, and precision agriculture) in 28 agricultural technology sectors. The results of the AHP analysis showed that 'alternative energy' was found to be a top priority among the agricultural technology sectors, and 'shallow depth drain in rice paddy' was a top priority for agricultural technology. Also, the 'marketability' in soil and water sectors, 'mitigation' in crop management, and 'adaptability' in energy efficiency and alternative energy were given higher priority. The results of this study can be used as a good source for strategic CSA preparation and application.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.59-77
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• 2000

This study was carried out to investigate on several factors, which contaminative the water quality through the water pipe during feeding water, in 42 largescaled apart-ments(total 84 cases) and assayed the Volatile Organic Compounds(VOCs) and concen-tration of heavy metals that inflow and outflow in reservior water in Jeonnam area(Mokpo, Suncheon, Yeosu) from January 1999 to December 1999. The results obtained were summarized as follows ; 1. The quality of the water pipe composition in the order of frequency in the quality of water pipes were Copper(45.2%)> Zinc(38.9%)> Stainless steel(9.5%)> PVC(4.8%)> PM(2.4%) in observing 42 sites. All of the drain pipes were used the cast iron quality. 2. The result of certification curve from 12 items(17kind) of VOCs was $1.0-4.0{\mu{g}}/{\ell}$ range, a coefficient of correlation was shown 0.99 over. A MDL of each substance range was within $0.1-1.0{\mu{g}}/{\ell}$. 3. The result of the assay, 5 kinds(Viny chloride, Dichloromethane, Ethylbenzene, M,P-xylene, Styrene) of the VOCs of 14 kinds was not detected and the other items were detected slightly. The detection rate of one item and over in total VOCs samples, were 25.9% in inflow and 27.9% in outflow. And frequency of detect in inflow/outflow of THM(Chloroform, Bromodichloro-methane, Dibromochloromethane, Bromoform) were shown higher than 94.1%, 97.0% each stages. It comes to the conclusion that all of the samples were reason able for drinking water standards. 4. The coefficient of correlation were reasonable, it shown 0.999 over in $0.1-1.0{\mu{g}}/{\ell}$ of a measuring range conditions of 4kinds in organic substance(Zn, Cu, Fe, Mn). 5. The results were showed suitability in 78 cases(92.9%) and unsuitability in 6 cases (7.1%), in 84 cases of in organic substances. Compare to inflow stage, mean concentrations of heavy metal, were increased slightly in Zn, Cu, Fe except Mn than outflow stage. The result of the mean concentration in organic substance inflow and outflow in the apartment water tank using Pair-compared T-test, in 95% reliance index, were $0.179mg/{\ell}(0.151-0.307mg/{\ell})$ in Zinc, $0.136mg/{\ell}(0.113-0.230mg/{\ell})$ in Copper, $0.052mg/{\ell}(0.048-0.098mg/{\ell})$ in Fe, and there was a bit growing tendency but there was no differece in Mn. 6. The mean concentration of Copper which used Cu pipe as a water supply pipe in apartment were $0.216mg/{\ell}(0.161-0.338mg/{\ell})$ in case of the Zine pipe were $0.286mg/{\ell}(0.204-0.435mg/{\ell})$. It shows that the detection rate was more higher than the other material used in Cu or Zn as the water supply pipe. We supposed to Cu and Zn substance were gushing out water supply pipe.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.8
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• pp.444-451
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• 2016

Most research on membrane fouling models in the past are based on theoretical equations in lab-scale experiments. But these studies are barely suitable for applying on the full-scale spot where there is a sequential process such as filtration, backwash and drain. This study was conducted in submerged membrane system which being on operation auto sequentially and treating wastewater from G-water purification plant in Incheon. TMP had been designated as a fouling indicator in constant flux conditions. Total volume of inflow and SS concentration are independent variables as major operation parameters and time-series analysis and prediction of TMP were conducted. And similarity between simulated values and measured values was assessed. Final prediction model by using genetic algorithm was fully adaptable because simulated values expressed pulse-shape periodicity and increasing trend according to time at the same time. As results of twice validation, correlation coefficients between simulated and measured data were $r^2=0.721$, $r^2=0.928$, respectively. Although this study was conducted limited to data for summer season, the more amount of data, better reliability for prediction model can be obtained. If simulator for short range forecast can be developed and applied, TMP prediction technique will be a great help to energy efficient operation.

• Journal of Korean Society on Water Environment
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• v.39 no.3
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• pp.231-239
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• 2023

Public sewage treatment facilities are a necessary infrastructure for public health that treat sewage generated in cities and basin living areas and discharge it into rivers or seas. Recently, the role of public sewage treatment is receiving attention as a place of use of wastewater-based epidemiology (WBE), which analyzes human specific metabolic emissions or biomarkers present in sewage to investigate the environment to which the population is exposed in the water drain. WBE is mainly applied to investigate legal and water-law drug use or to predict and analyze the lifestyle of local residents. WBE has also been applied to predict and analyze the degree of infectious diseases that are prevalent worldwide, such as COVID-19. Since sewage flowing into public sewage treatment facilities includes living information of the population living in the drainage area, it is easy to collect basic data to predict the confirmation and spread of infectious diseases. Therefore, it is necessary to establish a new role of public sewage treatment facilities as an infrastructure necessary for WBE that can obtain information on the confirmation and spread of infectious diseases other than the traditional role of public sewage treatment. In South Korea, the sewerage supply rate is about 95.5% and the number of public sewage treatment facility is 4,209. This means that the infrastructure of sewerage is fully established. However, to successfully drive for WBE , research on monitoring and big-data analysis is needed.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.217-225
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• 2003

An experimental study was conducted to evaluate the smeared effect due to mandrel penetration into soft ground for a vertical drain installation. Laboratory tests were performed to investigate the formation of a smear zone, the variations of strength, and the consolidation characteristics in the disturbed zone using two types(CL at Yangsan site and OH at Pohang site) of soft clayey soils. The smear zone effect was evaluated focusing on mandrel shape, mandrel size, penetration speed, and ground condition. Based on laboratory test results, the diameter of the smear zone$(d_s)$ ranged from 3.08 and 3.92 times that of mandrel$(d_m)$. It was also found that the $(d_s/d_m)$ value of the circular shape of the mandrel is smaller than those of square and rectangular shapes. The value of $(d_s/d_m)$ decreased with larger mandrel size, lower penetration speed in the CL soil, and higher penetration speed in the OH soil. However, natural water content was minimally affected by $(d_s/d_m)$. Respectively, the coefficients of horizontal consolidation$(C_{hs})$ and horizontal Permeability$(K_s)$ of smear zone ranged from 0.81 to 0.87 times, and 0.73 to 0.83 times those of the undisturbed zone. Based on this study, the values of $C_{hs}, K_s$ and unconfined compressive strength$(q_{us})$ in the smear zone were the lowest at close vicinity of the mandrel and increased linearly with distance from the mandrel. Further, the $(q_{us})$ varied from 0.5 to 0.9 times that of the undisturbed zone strength.

• Journal of the Korean GEO-environmental Society
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• v.8 no.5
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• pp.5-14
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• 2007

The quantity of noxious wastes generated by the growth in industrialization and population in all over the world and its potential hazards in subsurface environments are becoming increasingly significant. The extraction of the contaminant from the soil and movement of the water are restricted due to the low permeability and adsorption characteristics of the reclaimed soils. Incorporated technique with PVDs have been used for dewatering from fine-grained soils for the purpose of ground improvement by means of soil flushing and soil vapor extraction systems. This paper is to evaluate several key parameters that affected to the performance of the PVDs specifically with regard to: well resistance of PVD, zone of influence, and smear effects. In the feasibility of contaminant remediation was evaluated in pilot-scale laboratory experiments. Well resistance is affected on the vertical discharge capacity of the PVDs under the various vacuum pressures. The discharge capacity increases consistently in areal extents with higher applied vacuum up to a limiting vacuum pressure. The head values for each piezometer at different vacuum pressures show that the largest head loss occurs within 14 cm of the PVD. Air flow rates and head losses were measured for the PVD placed in the model test box and the gas permeability of the silty soils was calculated. Increasing the equivalent diameter results in a decrease in the calculated gas permeability. It is concluded that the gas permeability determined over the 1,500 to 2,000 $cm^3/s$ flow rates are the most accurate values which yields gas permeability of about 3.152 Darcy.