• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.211-214
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• 2007

The purpose of this study was to establish the basic information for natural drainage capacity assessment in urban area. We sorted midium watershed of Han river and Nak-dong river, and selected 30 rainfall events during 1995 to 2000 according to high level of damage. The inundated area showed high watershed slope about 25% and it indicated the greatest damage around the watershed located in 200-300m of altitude. Besides, the great damage by inundation was occurred in the mountainous agriculture region, where the forest scale was high and the urbanization was being progressed gradually. However, inundated area was small in case of grassland, water tone such as riparian area, bare ground and wetland. Moreover, the inundated area was different according to river shape and characteristics of river distribution such as the density of the stream order, conservation constant of the river system, and the number of undulations in the watershed. Therefore, it showed that land use, river shape and distribution characteristics of stream influence on inundation.

• 펄프종이기술
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• 제31권1호
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• pp.52-60
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• 1999

Drainage rate in wet-end, which has significant influences on the production capacity, product quality and process economics in papermaking, becomes an important factor in the modern high speed papermaking processes owing to increased level of fines contained in today's pulp materials and increased papermaking system closure. A study was carred out to investigate the influence of beating and fines content on natural and vacuum dewatering using a vacuum drainage tester. Increase in beating and accumulation of fines in the stock decreased natural dewatering, Vacuum dewatering effect, however, increased substantially as beating and fines content were increased. But this increase in vacuum dewatering decreased again when a stock is severely beaten or fines content is greater than 35%. Above this level of fines content, mobile fines migrates to the interstices of the forming web to cause sealing or plugging which restrict fluid movement through the web.

• 한국항만학회지
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• 제12권2호
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• pp.329-336
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• 1998

Sandmats are used to dissipate trapped water rapidly from the embankment built on marine soft ground. At present, however, it becomes difficult to obtain qualified sands since natural resources such as river sand are to exhausted. Also, low permeability of sand may cause low degree of consolidation and instability of embankment. In this study, design and construction methods was discussed. Drainage capacities of prefabricated horizontal drains which were installed in highway construction site are investigated in order to find possible substitution for river sands as drainage materials. On the basis of measurement data at the construction site, it was concluded that use of the prefabricated horizontal drains shows satisfactory drainage capacity without instability of embankment.

• 한국조경학회지
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• 제27권5호
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• pp.170-180
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• 2000

The surface-drainage system, which consists of bio-swale and detention-infiltration Basins and carries out the function of temporary detention-infiltration of runoff, is defined as the "natural drainage system". It is an environmentally sound and economically beneficial practice to reduce run-off by retaining it in swales as much as possible and letting run-off infiltrate into the ground. In order to estimate appropriate capacity of swales, it is necessary to know how long will it take for certain depths of water to infiltrate. The ponding times, or infiltration times, of various depths and of various soil textures, could be estimated with the Green-Ampt Infiltration Model. Included soil textures are loamy sand, sandy loam, loam, silty loam, sandy clay loam and clay loam. Ponding depths are from 10cm to 100cm intervals. Newton-Raphson method is used for the solution of the Green-Ampt equation by a computer program. The computer program was written with the FORTRAN Developer 4.0 v.. Selected ponding depth is acceptable when the sum of the ponding time and the breeding time of mosquitoes is less than the tolerance period of innundation of grasses and trees.and trees.

• 한국환경과학회지
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• 제7권2호
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• pp.149-156
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• 1998

Enoronmental problems caused by certain geologic conditions Include pollution of soil by heavy metal, acidization of souls , acid mine drainage, Pound-water pollution, and natural radioactivity, as well as zoo-logical hazards such as landslide and subsidence. The acrid mine drainage contains large amount of heavy metals nO, therefore. cause serious pollution onto the nearby drainage systems and soils. In spite of this prospective environmental danger, few studies have been done on the acid mine drainage derived from non-metallic ore deposits such as pyrophyllitefNapseok) deposits. The sudo-bearing pyrophyllite ores, alteration zones, and mine talllngs of pyrophylllte deposits produce acrid mine drainage by the okidation of weathering. Compared to the fresh host rocks, the ores and altered rocks of pyrophyllite deposits produce acidic solution which contain higher amount of heavy metals because of OeP lower buffering capacity to acrid solution. The pus of urine water and nearby stream water of pyrophyllite deposits are 2.1~3.7, which are strong- ly acidic and much lower than that (6.2~7.2) of upstream water and than that (6.8~7.6) of the stream water derived from the non-mineralized area. This study reveals that this acrid mine drainage can affect the downstream area which is 8km far from the pyrophyllite deposits, even though the drain Is diluted with abundant non-contaminated river water This suggmists that not only acid mine drainage but also the sulfide-bearing sediments originated from the pyrophyllite deposits move downstream and form acidic water through continuous oxidation reaction. The heavy metals such as Pb, Zn, Cu, Cd, Nl, Mn and Fe are enriched In the mine water of low pH, and their contents decrease as the pH of mine water Increases because of the Influx of fresh stream wainer. SoUs of the Pyrophyulte deposits are characterized by high contents of heavy metals. The stream sediments containing the yellowish brown precipitates formed by neutralization of acid mine drainage occur in all parts of the stream derived from the pyrophyllite deposits, and the sediments also contain high amounts of heavy metals. In summary, the acid mine drainage of the pyrophyllite deposits is located in the upstream part of Hoidong water reservoir in Pusan contains large amounts of heavy metals and flows into the Holdong water reservoir without any purification process. To protect the water of Holdong reservoir, the acid mine drainage should be treated with a proper purification process.

• 한국수자원학회논문집
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• 제40권3호
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• pp.215-221
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• 2007

본 연구에서는 침투정 설치 시 침투정 토양표면의 막힘 현상에 따른 침투능 저하를 감소시키기 위한 빙안을 강구 하고자 하였다. 또한 각기 다른 토양특성에 따른 침투능의 변화를 알아보기 위하여 여러 다른 실험조건에서 침투능의 변화를 관찰하였다. 실험결과에 의하면 침투정 설치 시 침투정의 하부토양은 자갈이나 가급적 입경이 큰 토양을 설치함으로써 침투정으로부터 우수를 빠른 시간 내에 배수시킬 수 있을 것으로 사료된다. 하지만 장기적으로 시간이 경과함에 따라서 침투능이 감소하는 경향을 보이는 것을 고려할 때 토양 내부에 부유토사의 침투에 따른 막힘 현상이 발생되고 있는 것으로 사료된다. 하부 자연 토양의 다짐을 방지하기 위하여 자연토양 상부에 가급적 얕은 깊이로 모래를 설치하고 가급적 굵은 자갈을 상부에 설치하여 저류능과 수두를 높여 침투능을 향상시키는 것이 바람직하다. 또한 정기적으로 침투정에 발생하는 crust(경화 토피층)를 제거하고 침투정내 모래를 수시로 교체하여 원래의 침투능을 유지하도록 하는 것이 필요하다.

• 한국농공학회논문집
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• 제65권4호
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• pp.25-32
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• 2023

KDS (Korean Design Standard) for agricultural drainage is a planning standard that helps determine the appropriate capacity and type of drainage facilities. The objective of this study was to analyze the inundation of the agricultural basin considering the current design standard and the critical rainfall duration. This study used the rainfall durations of 1-48 hour, and the time distribution method with the Chicago and the modified Huff model. For the runoff model, the NRCS (Natural Resources Conservation Service) unit hydrograph method was applied, and the inundation depth and duration were analyzed using area-elevation data. From the inundation analysis using the modified Huff method with different rainfall durations, 4 hours showed the largest peak discharge, and 11 hours showed the largest inundation depth. From the comparison analysis with the current method (Chicago method with a duration of 48 hours) and the modified Huff method applying critical rainfall duration, the current method showed less peak discharge and lower inundation depth compared to the modified Huff method. From the simulation of changing values of drainage rate, the duration of 11 hours showed larger inundation depth and duration compared to the duration of 4 hours. Accordingly, the modified Huff method with the critical rainfall duration would likely be a safer design than the current method. Also, a process of choosing a design hydrograph considering the inundation depth and duration is needed to apply the critical rainfall duration. This study is expected to be helpful for the theoretical basis of the agricultural drainage design standards.

• 한국조경학회지
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• 제38권5호
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• pp.80-92
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• 2010

본 연구는 서울시에 있는 산지형 도시근린공원을 대상으로 하여 배수시설의 특성을 밝히는 것이다. 구체적으로는 배수현황, 우수유출량, 배수유출량,그리고 배수시설용량을 산출하고, 우수유출량과 배수유출량을 비교분석을 위해 배수유출량계수를 산출하고 배수시설의 설치규모를 분석하고자 배수시설용량계수를 도출하여 배수구역 및 공원별로 비교분석 하였다. 본 연구의 주요 결과는 다음과 같다. 1. 배봉산공원의 전체배수면적은 34.13ha로서 배수유형별로는 표면배수구역 15.05ha(44.09%), 개수로배수구역 14.60ha(42.78%), 자연수로배수구역 4.48ha(13.13%)를 차지하고 있어, 상대적으로 표면배수구역이 넓어 자연상태의 표면유출이 많았다. 한편, 오금공원의 전체배수면적은 20.39ha로서 표면배수구역 2.52ha(12.36%), 자연수로배수구역 0.56ha(2.75%), 개수로배수구역 10.14ha(49.73%), 산마루측구배수구역 7.17ha(35.16%)를 차지하고 있어 상대적으로 인공적인 배수시설구역이 높게 나타났다. 2. 배봉산공원의 총우수유출량은 $7.28m^3/s$로서 배수구역별 우수유출량 평균은 $0.23m^3/s$이며, 각 배수구역은 규모가 크고 길어서 우수유출거리가 크게 나타났다. 한편, 오금공원의 총우수유출량은 $4.37m^3/s$로서 배수구역별 우수유출량 평균은 $0.12m^3/s$으로 배봉산공원에 비해 절반 정도로 나타났으며, 지형의 기복이 뚜렷하지 않고 배수시설이 많아 배수구역이 작게 세분되었다. 3. 배봉산공원에 개수로가 설치된 배수구역의 전체 배수유출량은 $11.58m^3/s$이고, 배수구역별 평균배수유출량은 $0.77m^3/s$, 평균배수유출량계수는 5.26이었다. 한편, 오금공원은 전체 배수유출량은 $15.40m^3/s$이고, 배수구역별 평균배수유출량은 $0.34m^3/s$, 평균 배수유출량계수는 8.87로 나타났다. 배봉산공원은 배수구역별로 개수로의 규모와 경사 등이 커서 상대적으로 평균 배수유출량이 높게 나타났지만, 배수유출량계수는 배수구역별 우수유출량이 적은 오금공원 보다 상대적으로 낮게 나타났다. 4. 배봉산공원의 전체 배수시설용량은 $554.54m^3$로서, 배수시설용량계수는 평균 179.83으로 나타났다. 한편, 오금공원은 전체 배수시설용량은 $717.74m^3$로서, 배수시설용량계수는 평균 339.69로 나타났다. 오금공원이 배수시설용량계수가 훨씬 높게 나타나 상대적으로 오금공원에서 배수유역별로 설치된 배수시설의 총량이 많으며, 집약적으로 설치된 것임을 의미한다. 본 연구에서는 자연적이고 조방적인 배수체계로 조성된 배봉산공원과 인공적이고 집약적인 배수체계로 조성된 오금공원을 대상으로 하여 배수유출량계수와 배수시설용량계수를 산정하여 비교분석함으로써 산지형 도시공원의 배수시설의 특성을 규명하였으며, 향후 공원의 배수유출량과 배수시설용량을 비교분석하기 위한 방법론을 제시하였다. 본 결과는 도시공원의 배수시설 계획 및 설계와 우수의 저류 및 생태적 가치를 증진시키는 친환경적인 배수체계를 구축하는 자료로 활용할 수 있다. 도시공원의 배수시설 특성은 지형 및 경사, 식생, 배수유형 등에 영향을 받게 되어 공원에 따라 그 결과가 달라질 수 있으므로 향후 더욱 많은 공원을 대상으로 한 연구와 공원에서 우수를 저류하고, 생태적 가치를 증진시키는 친환경적인 배수체계 및 방법에 관한 연구가 필요하다.

• The Korean Journal of Ecology
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• 제25권1호
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• pp.63-70
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• 2002

This study examined the changes of water quality in relation to distribution of hydrophytes, and the purification capacity of Zizania latifolia to improve the effluent from Munpyeong stream from March 1997 to December 1999. While the concentration of nitrogen and phosphorous in water were increased during the farming season, those decreased, during the streaming down to paddy and drainage areas. In investigated sites, the Z. latifolia was dominant community according to the development of the natural wetlands. Furthermore, it formed a large community owing to its high adaptability to environmental changes in the agriculture lands. In September, the leaves productivity of the Z. latifolia were 4,032g D.W/$m^2$and roots were 7,680gD.W/$m^2$. The purification capacity of the Z. latifolia for NH$_3$-N, $No_3$-N, and PO$_4$-P were 13.41, 17.07, and 4.58 respectively during 5 days. The results suggested that it needs to establish wetlands vegetated by hydrophytes to improve the water quality of the effluent from agricultural lands.

• 한국농공학회논문집
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• 제61권4호
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• pp.75-86
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• 2019

Recently, natural disasters due to abnormal climates are frequently outbreaking, and there is rapid increase of damage to aged agricultural infrastructure. As agricultural infrastructure facilities are in contact with water throughout the year and the number of them is significant, it is important to build a maintenance management system. Especially, the current maintenance management system of pumping and drainage stations among the agricultural facilities has the limit of lack of objectivity and management personnel. The purpose of this study is to develop a performance evaluation model using the factors related to performance degradation of pumping and drainage facilities and to predict the performance of the facilities in response to climate change. In this study, we focused on the pumping and drainage stations belonging to each climatic zone separated by the Korea geographical climatic classification system. The performance evaluation model was developed using three different statistical models of POLS, RE, and LASSO. As the result of analysis of statistical models, LASSO was selected for the performance evaluation model as it solved the multicollinearity problem between variables, and showed the smallest MSE. To predict the performance degradation due to climate change, the climate change response variables were classified into three categories: climate exposure, sensitivity, and adaptive capacity. The performance degradation prediction was performed at each facility using the developed performance evaluation model and the climate change response variables.