• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.36-36
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• 2012

Drainage water in lowland paddy fields is quantitatively influenced recycle and/or repeated irrigation by irrigation facilities, i.e. pumps, check gates, small reservoirs and so on. In those drainage channels, nutrients accumulation and increasing organic matters are considered to be occurred, and water quality would be degraded not only environmental aspect but irrigation purpose. In general, Total Nitrogen (T-N) is interested water quality index in irrigation water, because high nitrogen concentration sometimes caused decreasing rice production by excess growth and fallen or degrading quality of taste, then, farmers would like to clear water less than 1mg/L of T-N concentration. In drainage channel, it is known that the nitrogen concentration change is influenced by physical, chemical and biological properties, i.e, stream or river bed condition, water temperature, other water quality index, and plant cover condition. In this study, discharge data (velocity and level) in a drainage channel was monitored by an Acoustic Doppler system and water quality was sampled at same time in 2011. So those data was analyzed by multi regression model to realize hydrological and environmental factors to influence with nitrogen concentration. The results showed the difference tendency between irrigation and non-irrigation period, and those influenced factors would be considered in water quality model developing in future.

• Korean Journal of Hydrosciences
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• 제7권
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• pp.21-35
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• 1996

This Study is to develop the suitable hydrologic models for determination of the size and location of detention storage facilities to restrain stormwater runoff in urban areas. Hypothetical areas of two levels are considered to seize the hydrologic response characteristics. A one-square-kilometer ares is selected for the catchment level, and a 10-square-kilometer area consisting of 10 catchments is adapted at the watershed level as representative of urban drainage area. In this analysis, different rainfall freqyencies, land uses, drainage patte군, basin shates and detention storage policies are considered. Folw reduction effect of detention storage facilities is deduced from storage ratio and detention basin factor. A substantial saving in detention storage volumes is achieved 노두 the detention storage is planned at the watershed level rather than the catchment level. For the application of real watersheds, two watersheds in Seoul metropolitan area-Jamshil 2 and Seongnae 1-are selected on the basis of hydrologic response charactaristics. Through the regression analysis between dimensionless deterntion storage volume, dimensionless upstream area ratio and reduction rate of storage ratio, the regression equations to determine the size and location of detention storage faclities are presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.363-366
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• 2005

Social survey and auditory experiment on residential noises such as floor impact, air-bome, bathroom, drainage and traffic noises were conducted to investigate the effects of sensitivity and background noise levels on subjective response to residential noises. Results of survey showed that multiple questions for sensitivity to noise have a more power for discrimination against subjective response to noise than single question. It was also found that the correlation between sensitivity and annoyance was relatively low, but the differences in annoyance between sensitivity groups were significant. Result of auditory experiment showed that effects of sensitivity on annoyance were different according to noise type and noise level. It was also shown that the difference in annoyance between the lowest sensitive stoup and the highest sensitive group was significant in low noise level. The effects of background noise on subjective responses to noise was also different according to noise source and noise level, and were significant in low noise level of airborne and drainage noise.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.399-402
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• 2007

This project is the 1st. stage for the foreshore reclamation at Jang-Hang area and its scope is to construct a seawall as outer facilities, road adjacent to the seawall and drainage gate. for the safe protections of the facilities at the reclaimed land hereafter, we adopted the mild slope rubble mound type for the seawall structure which was excellent in interrupting the wave overtopping, as a result of numerical & hydraulic model test about alternative 4 sections. For the flooding prevention of the reclaimed land, we planned the drainage system that could make the flood water level lower than the reclaimed land level. Also, we planned the eco-friendly waterfront area with 8 nature themes through the whole seawall sections.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.367-371
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• 2005

Social noise survey on multiple residential noises such as nut impact, air-borne, bathroom, drainage and traffic noises was conducted to investigate major variables affecting the overall satisfaction for noise environment The effect of individual noise perception on the evaluation of the overall noise environment was investigated through a questionnaire survey on annoyance, disturbance and noise sensitivity. Auditory experiments was also undertaken to determine noise level according to the percent of satisfaction for individual noise source. As a result of survey, it was found that satisfaction for floor impact noise most greatly affects the overall satisfaction for noise environment and annoyance most greatly affects the satisfaction for individual noise sources. Result of auditory experiment showed that the noise level of floor impact noise by bang machine, airborne, drainage and traffic noise corresponding to 50% satisfaction is 44dB($L_{i,Fmax,AW}$) and 40dBA, respectively.

• 농업생명과학연구
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• 제44권6호
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• pp.23-26
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• 2010

펄라이트자루를 사용한 수경재배에서 급액관리방식의 일종인 배액전극제어법에 필요한 배액 이동매개체를 선발하기 위해서 시판되고 있는 친수성 매트 중에서 극세사, 융, 면 등의 배양액 흡수속도를 분석했다. 또한, 선택된 매트가 배액전극제어법을 적용하였을 때에도 높은 흡수속도를 갖는지 알아보기 위해 연구를 수행하였다. 실험결과 면이 가장 수분보유력이 뛰어났으며, 배액전극제어법을 적용했을 때에도 가장 적합한 것으로 나타났다.

• 한국물환경학회지
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• 제26권5호
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• pp.761-767
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• 2010

This study introduces a model of territorial analysis on Chungcheongnam-do Nonsan-chun valley area, which gives an example of a method of selecting the management area for non-point pollution source from land use to help eliminate its source. High discharge load per unit area signify high level of land ratio with high level of basic unit of development load (including factory sites, school sites, roadways), which mean that there are a significant level of urbanization. It is these areas with the examination of the water quality of the nearby river that should be considered as the management area for non-point pollution source. Thus, the management area for non-point pollution source should be sought in areas with high discharge load per unit area and high density of water pollution area. When level of drainage is high the pollution density level is relatively lower, and when the level of drainage is low the density level is relatively higher. The level of pollution from non-point pollution source is much lower with more water flowing through. The possible non-point pollution source areas that were selected with these standards were then examined with the distance from the river, the slope angle, land usage, elevation, BOD discharge density load, T-N discharge density load, T-P discharge density load, and were given a level one through five. Out of the possible areas Nonsan-si Yeonmu-eup Anshim-li was the densest area, and it was given level one. The level one area should be examined further with the field analysis to be selected as the actual management area for non-point pollution source.

• 한국터널지하공간학회 논문집
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• 제17권4호
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• pp.429-440
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• 2015

본 연구에서는 배수형 쉴드터널 적용시 작용수압의 저감을 평가하기 위해 모형실험장치를 개발하여 배수 및 비배수 조건에서 작용수압 차이를 실험하였다. 모형실험 결과 배수 조건에서 간극수압 증가율이 감소하는 경향을 보였고, 비배수 조건에 비해 전응력이 더 작게 나타나 모형터널 내 지하수 유입에 의해 작용수압이 저감되는 것으로 나타났다. 현장계측 결과 쉴드터널 배면 지반 내 작용수압은 지하수위로 계산되는 수압($r_w{\cdot}H$)보다 약 11~22%정도 적게 나타났다. 모형실험 및 현장계측 결과에서 배수 및 비배수 조건의 이론적인 설계수압과 작용수압의 차이가 나타났는데, 배수형 쉴드터널 적용시 기존 설계수압보다 감소된 수압을 적용하는 것이 가능할 것으로 판단되며, 수압 감소를 통해 세그먼트 단면 축소도 가능할 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.34-45
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• 2011

For the Hancheon drainage area in Jeju island, a groundwater flow model using Visual MODFLOW was developed to simulate artificial recharge through injection wells installed in the Hancheon reservoir. The model was used to analyze changes of the groundwater level and the water budget due to the artificial recharge. The model assumed that $2{\times}10^6m^3$ of storm water would recharge annually through the injection wells during the rainy season. The transient simulation results showed that the water level rose by 39.6 m at the nearest monitoring well and by 0.26 m at the well located 7 km downstream from the injection wells demonstrating a large extent of the affected area by the artificial recharge. It also shown that, at the time when the recharge ended in the 5th year, the water level increased by 81 m at the artificial reservoir and the radius of influence was about 2.1 km downstream toward the coast. The residence time of recharged groundwater was estimated to be no less than 5 years. The model also illustrated that 15 years of artificial recharge could increase the average linear velocity of groundwater up to 1540 m/yr, which showed 100 m/yr higher than before. Increase of groundwater storage due to artificial recharge was calculated to be $2.4{\times}10^6$ and $4.3{\times}10^6m^3$ at the end of the 5th and 10th years of artificial recharge, respectively. The rate of storage increase was gradually diminished afterwards, and storage increase of $5.0{\times}10^6m^3$ was retained after 15 years of artificial recharge. Conclusively, the artificial recharge system could augment $5.0{\times}10^6m^3$ of additional groundwater resources in the Hancheon area.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.265-275
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• 2017

Purpose: This study aims to identify the most stable boring shape among the circle, square, and inverted-triangle types in order to be applied to the development of a tractor-pulled underdrain boring device. Methods: The underdrain boring devices designed with the circle, inverted triangle, and square types were analyzed by numerical analysis, and they were evaluated by soil moisture and underground water level in the test field. Results: The results of the numerical analysis indicated that the increases in displacement, and strain when a uniform load is placed on the surface soil with soil weight were in the order of the inverted-triangle type, square type, and circle type. The soil moisture content and the underground water level after rainfall showed the largest difference in the order of the circle type, square type, and inverted-triangle type, indicating that the circle type had the largest drainage effects after rainfall. Conclusions: The overall findings of this study show that the circle type is the most stable among the circle, square, and inverted-triangle types.