• 한국농공학회지
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• 제45권6호
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• pp.109-118
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• 2003

As a fundamental research to establish a safety operation plan for irrigation dams, this study presents hydrologic analysis conducted in Sungju Dam watershed based on various rainfall data. Especially those reservoirs without flood control feature are widely exposed to the risk of flooding, a safe and optimized operation program need to be improved against arbitrary flooding. In this study, reservoir routing program was developed and simulated for reservoir runoff estimation using WMS hydrology model. The model simulated the variations of reservoir elevation under the condition of open or closed emergency gate. In case of closed emergency gate, water surface elevation was given as 193.15 m, and this value exceeds the dam crest height by 1.65 m. When the emergency gate is open, the increment of water surface elevation is given as 192.01 m, and this value exceeds dam crest height by 0.57 m. As an alternative plan, dam height increase can be considered for flood control under the PMP (Probable Maximum Precipitation) condition. Since the dam size is relatively small compare to the watershed area, sound protection can be expected from the latter option rather than emergency gate installation.

• Asian Journal of Innovation and Policy
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• 제10권2호
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• pp.212-235
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• 2021

In spite of the increasing popularity of the Ricardian model for the study of the impact of climate change on agriculture, there has been few attempts to examine the role of interregional spillovers in this framework and all of them rely on geographical proximity-based weighting schemes. We remedy to this gap by focusing on the spatial externalities of surface water flow used for irrigation purposes and demonstrate that farmland value, the usual dependent variable used in the Ricardian framework, is a function of the climate variables experienced locally and in the upstream locations. This novel approach is tested empirically on a spatial panel model estimated across the counties of the Southwest USA over 1997-2012. This region is one of the driest in the country, hence its agriculture relies heavily on irrigated surface water. The results highlight how the weather conditions in upstream counties significantly affect downstream agriculture, thus the actual impact of climate change on agriculture and subsequent adaptation policies cannot overlook the streamflow network anymore.

• 한국농공학회지
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• 제45권7호
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• pp.57-69
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• 2003

To evaluate nutrient dynamics with different fertilization in paddy field and develop water quality model, mass balance analysis was performed during growing season of 2001-2002 in field experimental plots irrigated with groundwater. As a result of water balance analysis, most of outflow was surface drainage as about half of total outflow and about 500mm was lost by evapotranspiration. The water budget was well balanced. The runoff from paddy field was influenced by rainfall and forced drain. Especially runoff during early cultural periods more depends on the forced drain. As a result of mass balance analysis, most of nutrient was input by fertilization and lost by plant uptake. Significant amount of nitrogen were supplied by precipitation and input from upper paddy field, comprising 12%∼28% of total inflow. Nutrient loading by surface drainage was occurred showing about 15%∼29% for T-N and 6%∼13% for T-P. The response of rice yield with different fertilization was not significant in this study. Water quality model for paddy field developed using Dirac delta function and continuous source was calibrated and validated to surface water quality monitoring data. It demonstrates good agreement between observed and simulated. The nutrient concentration of surface water at paddy field was significantly influenced by fertilization. During early cultural periods when significant amount of fertilizer was applied, surface drainage from paddy field can cause serious water quality problem. Therefore, reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Shallow irrigation, raising the weir height in diked rice fields, and minimizing forced surface drainage are suggested to reduce surface drainage outflow.

• 한국유기농업학회지
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• 제32권1호
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• pp.107-125
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• 2024

Tetracycline 계열 옥시테트라사이클린(OTC)과 클로르테트라사이클린(CTC) 그리고 penicillin 계열 아목시실린(AMX) 등 3종의 축산용 항생제를 관개수에 인위적으로 주입한 후 농업용수의 관개방법(지표점적관개, 지중점적관개, 스프링클러관개)에 따른 항생제의 토양중 잔류, 식물체로의 흡수이행량 그리고 작물생장지표 등을 조사하였다. 적상추와 열무 재배지역 토양중 축산용 항생제의 잔류농도는 큰 차이가 나타나지 않았으며, 축산용 항생제의 처리농도가 증가함에 따라 토양중 잔류농도도 유의성있게 증가하는 경향이었다(P < 0.05). 관개방법에 따라서는 토양중 축산용 항생제의 잔류량이 유의성 있는 차이를 나타내지 않았다(P > 0.05). 적상추와 열무의 가식부위(잎) 중 처리대상 3종의 축산용 항생제 모두 검출한계미만으로 나타나 작물의 안전성은 확보된 것으로 나타났다. 적상추와 열무 작물체로 훕수이행된 항생제를 대상으로 전이계수(translocation factor)를 조사한 결과, 토양으로부터 적상추 뿌리까지의 전이계수는 0.3 미만으로 나타났고, 토양으로부터 열무뿌리까지의 전이계수는 0.2이하로 나타났다. 관개방법별 그리고 축산용 항생제의 종류에 따라 전이계수가 유의성 있는 차이를 나타내지 않았다(P>0.05). 마지막으로, 적상추와 열무의 수확량도 관개방법별 그리고 항생제의 종류별로 유의성 있는 차이가 나타나지 않았다(P>0.05). 우리나라 하천에서 검출되는 축산용 항생제의 최대 50배 수준까지 유입될 경우 토양 내 잔류량은 지속적으로 증가할 것으로 평가되지만, 축산용 항생제의 작물체로 전이는 크게 나타나지 않을 것으로 나타났다. 하지만, 축산용 항생제의 농경지 토양내 지속적인 유입은 토양미생물상의 활성도, 종 다양성, 개체군에 영향을 끼쳐 장기적으로 바람직하지 못한 영향을 끼칠 수 있을 것이기에 지속적인 관리가 필요할 것이다.

• 대한치과보철학회지
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• 제37권4호
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• pp.433-453
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• 1999

There are a lot of elements affecting the success of implant prosthesis. The quality of surgical procedure is considered as one of the key factors. To avoid the excess heat generation is an important element of successful osseointegration and it can be achieved by using a gentle surgical technique with a sharp instrument in bone drilling. This study was performed to measure and analyze comparatively the heat transmitted to sur-rounding bone at a distance of 0.5mm from the periphery of the drill hole in each drilling stage. The results were as follows. In standard system, the temperature of surrounding bone tissue ranged from $29.2^{\circ}C\;to\;48.3^{\circ}C$ with irrigation and from $34.6^{\circ}C\;to\;84.3^{\circ}C$ without irrigation. And in wide system, the temperature of surrounding bone tissue ranged from $29.5^{\circ}C\;to\;52.5^{\circ}C$ with irrigation and from $34.8^{\circ}C\;to\;87.8^{\circ}C$ without irrigation. And the temperature ranges exceeded the threshold without irrigation, while showing less than the threshold by the cooling effect of irrigation. In comparing standard system with wide system, although there was no significant difference, ${\phi}4.3mm$ pilot and ${\phi}4.3mm$ twist drill of wide system showed high value and wide system showed slightly high elevation of temperature in all depth in fixture installation. In the finite element analysis, the calculated value by the Fourier's cooling law were applied to the bone drilling surface. And through analysis using different irrigation temperatures at $28^{\circ}C,\;15^{\circ}C\;and\;5^{\circ}C$, and according to the time. The result was that the cooling water at least below $15^{\circ}C$ was required to maintain the temperature of surrounding bone less than threshold in bone drilling, the cooling water below $5^{\circ}C$ was required to gain more sufficient cooling effect, and cooling over 5 seconds was needed after bone drilling for sufficient effect.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.194-194
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• 2016

Gansu, located in the northwestern region, is a typical agricultural province of arid, semiarid in China. The shortage of water resources is the biggest obstacle of Gansu Province's development, and the dry farming water-saving is the eternal theme of Gansu agricultural sustainable development. In recent years, intensify reform in Gansu, has walked out a successful way in the agricultural water-saving. Using the integrated river basin governance as opportunity, the total water-using quantity was regarded as rigidity to retrain, distributed to counties (districts), irrigated areas, towns, associations, groups step by step. Agricultural water price was substantially increased, with the surface water price from about $0.1RMB/m^3$ to more than $0.2 RMB/m^3$, and the ground water from zero to more than $0.1RMB/m^3$. Simultaneously, the difference water prices and over-quota water progression price markup were carried out. The transaction of water rights was encouraged to impel the peasant to establish the consciousness of saving-water. The regulatory documents were formulated to standardize the scope, condition, mode, program etc. of agriculture water-rights transaction, to guarantees the transaction of water rights is carries out in order. The pattern of farming was optimized and adjusted, reducing the high water-consumption crop, increasing economic crops with high benefit and low water-consumption, developing industrialized agricultures such as green house. The relative engineering and measuring facility were comprehensively improved, with the anti-seepage of canal system and the enforcement of dynamo-electric well, developing high-efficient water-saving irrigation and overall metering facilities. The water fine-grained management has realized, and obvious water-saving effect has obtained: water-using rate in the irrigation area by river water has brought up to 0.57 from 0.52, and by well water up to 0.84 from 0.76. Although the water price has increased, the proportion that the water rate expenditure accounted for the cost lasts decline, and the farmers' income has gone up. The peasants express, the used water is few, and it is few to till land, but the income is many, and life is better.

• Journal of Radiation Protection and Research
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• 제29권2호
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• pp.117-127
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• 2004

핵종 누출 사고시 논으로의 핵종 이동 평가를 위한 동적격실모델을 개발하였다. 개발된 모델에는 벼 재배에 필수적인 관개수를 고려하여 표면수 격실과 줄기기부흡수 개념을 도입하였고, 이식 전 쟁기질과 관개담수에 의한 토양 혼합을 고려하였으며, 벼 성장에 따른 뿌리흡수상수, 줄기기부흡수상수의 변화를 생체량의 함수로 모델링하였다. 모델의 타당성 조사를 위해 고리, 영광 및 울진 원자력 발전소 주변 지역에서 채취한 논 토양으로 벼를 재배하면서 벼 생육단계별로 수행된 $^{137}Cs$ 모의 침적 실험 해석에 모델을 적용하였다. 모델은 대체적으로 한 승수 내에서 실험 결과와 잘 일치하였다.

• 한국관개배수논문집
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• 제19권1호
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• pp.19-29
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• 2012

The data of the agricultural water quality survey network was analyzed between from 1990 to 2010 in order to propose effective plans for water quality management by analyzing the characteristics of agricultural lakes and the change of water quality. The result of the analysis shows that there is a correlation between water quality and items that can be a function of water depth such as dam height, dam length, dam height/dam length ratio and active storage/surface area of lake ratio. This means that, Korean agricultural lakes, there is a correlation between water quality and water depth. Water quality of the lakes that have lower than 5m of active storage/surface area of lake ratio (effective water depth) especially tends to get worse rapidly. The Chl-a and COD concentration of Korean agricultural lakes have a tendency to increase between June and September. Therefore, we recommend first taking a water quality improvement project for the lakes preformed watershed management project, and taking a preventive short-term water quality improvement project for the unperformed lakes before June among lakes that have lower than 5m of effective water depth.

• 한국농림기상학회지
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• 제13권2호
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• pp.69-78
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• 2011

벼는 전 세계 주요 식량 자원 중 하나이며, 특히 아시아 지역에서 벼 경작이 활발히 이루어지고 있다. 벼를 경작하기 위한 논은 다른 작물과 달리 모내기전에 논에 물을 가둬두며, 많은 양의 물이 관개용수로 사용된다. 따라서 신뢰도 있는 관개시기 및 논의 탐지는 효율적인 수자원 관리 및 물 수지 분석을 위해 반드시 필요한 요소이다. 본 연구에서는 MODIS 자료로부터 산출된 개선된 식생지수(Enhanced Vegetation Index, EVI)와 지표수분지수(Land Surface Water Index, LSWI)를 활용하여 관개시기와 논의 공간분포탐지를 실시했다. 한국의 이천 연구지와 일본 Mase 연구지를 대상으로 MODIS 기반의 관개시기 탐지 결과 관측자료와 각각 1일과 8일정도의 차이를 나타냈다. 이 결과는 MODIS 8일 단위 자료의 오차범위 내에서 신뢰도 있는 관개시기 탐지 결과를 나타낸 것으로 판단된다. 또한 관개시기 탐지 결과를 토대로 한국 전체를 대상으로 MODIS 기반의 논을 탐지하고 환경부 토지피복도의 논과 비교하였다. 그 결과, 논이 넓게 분포한 지역에서는 MODIS가 과대평가하는 결과를 나타냈으며, 규모가 작은 논에 대해서는 과소평가하는 결과를 나타냈다. 이는 MODIS 자료의 공간해상도(500m)가 한국 논의 규모를 표현할 정도로 세밀하지 못한 점과 산림, 도시, 호수 및 강 등을 제거하는 과정에서 오차가 발생했을 것으로 판단된다. 또한 Xiao et al.(2005)이 제안한 LSWI에 대한 임계값(+0.05)은 중국을 대상으로 개발된 값으로, 한국 논의 토지피복 복잡성을 잘 반영하지 못하여 오차를 발생시킨 것으로 사료된다. 따라서 신뢰도 있는 관개시기 및 논 탐지를 위해서는 한국 논의 규모 및 토지피복의 이질성을 체계적으로 고려한 LSWI의 임계값을 개발하여 적용할 필요가 있다.

• 한국환경농학회지
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• 제21권3호
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• pp.165-171
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• 2002

A study was conducted to investigate the seasonal changes in water quality of watershed in the Agricultural Environment Promotion Zone. Samples collected were 12 GW (ground water), 2 IW (irrigation water), 2 SW (stream water) in An-Dong City, 4 GW, 6 IW, 11 SW in Young-Yang Gun, and sampling was conducted separately during dry and rainy season. In the ground water, EC and ionic species, except pH, were higher than those in stream water, and especially $NO_3-N$ concentration exceeded the limitation of drinking water. Concentration of ions decreased as the sampling depth was far from the soil surface. During a rainy season, the concentrations of $NO_3-N$ and K in the stream water were slightly higher than those during season. COD was lower during dry season in Yong-Yang, while the trend was contrasted to An-Dong. These results suggest that ground water was polluted by fertilization and compost while streamwater was polluted by loss of soil and organic during the rainy season. Principal chemical components related with changing water quality were EC, $NO_3^-$, Ca, Mg, Na, $Cl^-$, $Cl^-$, $SO_4^-$ in ground water, whereas $NH_4-N$, K, Mg, $Cl^-$, $SO_4^-$ in stream water.