• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.225-225
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• 2017

농촌지역 관수공급의 대부분은 지하수, 하천, 저수지 등 주변의 다중수원을 활용하고 있지만, 지속적인 가뭄 발생시 농업용수의 부족현상을 일으키며, 농작물의 생산량과 품질에 많은 영향을 주는 원인이 된다. 밭작물의 경우, 재배작물별로 적절한 재배환경조성은 작물의 생산성에 매우 큰 영향을 주므로 생육에 필요한 알맞은 토양수분을 유지를 위해 적절한 관수공급이 중요하다. 이러한 농촌지역의 물부족 현상을 대비하여 효율적인 관수공급으로 인한 물관리와 대체 수자원의 확보 및 활용방안이 요구되며, 대체 수자원을 저류하여 관수공급을 효과적으로 사용하는 방법들이 다각적으로 검토되고 있다. 특히, 빗물을 집수하여 재사용 하여 작물을 재배하는 방법이 친환경적일 뿐만 아니라, 수자원을 재활용하기 때문에 비용적인 측면에서 가장 효율적이므로 이러한 빗물을 저류조에 집수하여 효과적으로 재사용 하여 관수공급하는 방법에 대한 필요성이 대두되고 있는 실정이다. 이에, 본 연구에서는 농촌지역에서 작물재배를 하기 위해 관수공급시 관정의 수량이 충분한 평상시는 관정펌프로부터 물을 길러 관수를 하도록 하였고, 관정의 수량이 부족한 비상시(가뭄)와 강우 예측시에는 저류조로부터 관수를 하도록 가뭄시나리오와 강우시나리오를 구축하였다. 효율적인 관수공급 운영을 위해 기상청의 7일 기상예보 자료를 획득하고 강우분석을 통해 저류량 예측을 하고 작물별 일관수공급량을 계산하여 물부족이 일어나지 않도록 최적의 운영방법론을 구축하였다. 이를 통해, 다중수원으로부터 확보된 수원을 저류조에 저장하여 가뭄과 같은 비상 상황에서 농업용수로 사용이 가능하도록 함으로써 비상 상황에서 농작물의 피해를 최소화할 수 있을 것으로 판단된다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.1
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• pp.28-38
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• 2012

This study was conducted to investigate growth performance, photosynthesis, water use efficiency (WUE), and stomatal conductance ($g_s$) of container seedlings of Liriodendron tulipifera and Zelkova serrata growing under three different irrigation periods (1 time/1 day, 1 time/2 days and 1 time/3 days) for high seedling quality. The root collar diameter and height of L. tulipifera and Z. serrata seedlings were highest with 1 time/1 day irrigation, whereas they were lowest with 1 time/3 days irrigation. The two species showed low drought tolerance. As irrigation period was shortened, biomass and seedling quality index (SQI) of the two species increased. The ratio of height to root collar diameter (H/D) and the ratio of below to aboveground biomass (T/R) of the two species were lower with 1 time/3 days than at other irrigation periods. L. tulipifera and Z. serrata seedlings showed significantly higher photosynthetic capacity with 1 time/1 day irrigation. As irrigation period was shortened, $g_s$ of two species increased, while their WUE decreased significantly (P<0.05) These results show that 1 time/1 day irrigation provides the most optimal water condition for container seedling production of two species and irrigation controlling is very important for growth and quality of container seedlings.

• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.9-22
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• 2009

Due to increasing concerns over issues with both water quantity and quality for turfgrass use, research was conducted to determine the response of five warm-season turfgrasses to deficit irrigation and to gain a better understanding of relative drought tolerance. St. Augustinegrass(Stenotaphrum secundatum [Walt.] Kuntze.) cultivars 'Floratam' and 'Palmetto', 'SeaIsle 1' seashore Paspalum(Paspalum vaginatumSwartz.), 'Empire' zoysiagrass(Zoysia japonica Steud.), and 'Pensacola' bahiagrass(Paspalum notatum Flugge) were established in lysimeters in the University of Florida Envirotron greenhouse facility in Gainesville. Irrigation was applied at100%, 80%, 60%, or 40% of evapotranspiration(ET). Evaluations included: a) shoot quality, leaf rolling, leaf firing; b) leaf relative water content(RWC), soil moisture content, chlorophyll content index(CCI), canopy photosynthesis(PS); c) multispectral reflectance(MSR); d) root distribution; and e) water use efficiency. Grasses irrigated at 100% and 80% of ET had no differences in visual quality, leaf rolling, leaf firing, RWC, CCI, and PS. Grasses irrigated at 60% of ET had higher values in physiological aspects than grasses irrigated at 40% of ET. 'Sealsle 1' and 'Palmetto' had a deeper root system than 'Empire' and 'Pensacola', while 'Floratam' had the least amount of root mass. Photosynthesis was positively correlated with visual assessments such as turf quality, leaf rolling, leaf firing, and sensor-based measurements such as CCI, soil moisture, and MSR. Reducing the amount of applied water by 20% did not reduce turfgrass quality and maintained acceptable physiological functioning.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.341-348
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• 2013

Maintenance of adequate soil tension or content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil tension and content for precision irrigation would allow optimal soil water condition to crops and minimize the adverse effects of water stress on crop growth and development. This research reports on a comparison of soil water tension and content variations in differently textured soils over time under drip irrigation using two different water management methods, i.e. pulse time and required water irrigation methods. The pulse time-based irrigation was performed by turning the solenoid valve on and off for preset times to allow the wetting front to disperse in root zone before additional water was applied. The required water estimation method was a new water control logic designed by Rural Development Administration that applies the amount of water required based on a conversion of the measured water tension into water content. The use of the pulse time irrigation method under drip irrigation at a high tension of -20 kPa and high temperatures over $30^{\circ}C$ was not successful at maintaining moisture tensions within an appropriate range of 5 kPa because the preset irrigation times used for water control could not compensate for the change in evapotranspiration during day and night. The response time and pattern of water contents for all of the tested soils measured with capacitance-based sensor probes were faster and more direct than those of water tensions measured with porous and ceramic cup-based tensiometers when water was applied, indicating water content would be a better control variable for automatic irrigation. The required water estimation-based irrigation method provided relatively stable control of moisture tension, even though somewhat lower tension values were obtained as compared to the target tension of -20 kPa, indicating that growers could expect to be effective in controlling low tensions ranging from -10 to -20 kPa with the required water estimation system.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.93-100
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• 2011

Maintenance of adequate soil water potential during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement within and below the rooting zone can facilitate optimal irrigation scheduling aimed at minimizing the adverse effects of water stress on crop growth and development and the leaching of water below the root zone which can have adverse environmental effects. The objective of this study was to evaluate the feasibility of using a portable irrigation controller with an Watermark sensor for the cultivation of drip-irrigated vegetable crops in a greenhouse. The control capability of the irrigation controller for a soil water potential of -20 kPa was evaluated under summer conditions by cultivating 45-day-old tomato plants grown in three differently textured soils (sandy loam, loam, and loamy sands). Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30 cm depths. Even though a repeatable cycling of soil water potential occurred for the potential treatment, the lower limit of the Watermark (about 0 kPa) obtained in this study presented a limitation of using the Watermark sensor for optimal irrigation of tomato plants where -20 kPa was used as a point for triggering irrigations. This problem might be related to the slow response time and inadequate soil-sensor interface of the Watermark sensor as compared to a porous and ceramic cup-based tensiometer with a sensitive pressure transducer. In addition, the irrigation time of 50 to 60 min at each of the irrigation operation gave a rapid drop of the potential to zero, resulting in over irrigation of tomatoes. There were differences in water content among the three different soil types under the variable rate irrigation, showing a range of water contents of 16 to 24%, 17 to 28%, and 24 to 32% for loamy sand, sandy loam, and loam soils, respectively. The greatest rate increase in water content was observed in the top of 10 cm depth of sandy loam soil within almost 60 min from the start of irrigation.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.303-310
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• 2020

This study was conducted on propagation use for conservation scheme of a threatened plant; Wikstroemia ganpi (Sieb. et Zucc.) Maxim(Geomundo false ohelo). The seed propagation was showed higher (95%) in storage and lower values in ground and cutting. Softwood cutting was higher than hardwood cutting and it was possessing higher ratio of rooting that increase concentration of IBA and NAA. It was determined that for Geomundo false ohelo seedling was effective than cutting. In-situ and ex-situ conservation and restoration of substitute habitats of Geomundo false ohelo is therefore necessary due to human trampling in the habitats, damage, natural selection, loss and suppression.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.6-14
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• 2003

북한의 식량 상황이 악화된 근본적인 원인은 생산 주체에 대한 인센티브 부족, 농업환경을 보면 경작지 면적이 전체 20% 정도로 낮고, 무상기일이 135-180일로 짧으며, 토양의 비옥도 저하, 삼림파괴로 인한 토양 유실증가, 가뭄, 홍수, 태풍과 같은 자연 재해가 계속되고 있다. 농업 구조적인 요인들로는 농업에 투입되는 에너지 부족(연료, 비료, 농약, 전기 등), 농업 기계화율 정도가 높았으나 노후화에 따른 예비 부품 부족으로 인한 활용률의 저하, 양질의 종자확보 부족, 갖추고 있는 관개 시설의 노후화로 인한 관개시설 활용과 관수 효율의 저하, 농산물 수확 후 수송과 저장 과정에서 손실증가 등을 들수 있다. (중략)

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.604-607
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• 2004

한국의 수자원은 연간 강수량이 세계 평균보다 1.3배나 많음에도 불구하고 높은 인구밀도와 지형적 조건, 관수시설 및 물에 대한 인식 부족으로 물 부족 현상이 현실로 다가오고 있다. 또한 많은양의 정수된 물이 송수과정에서 땅속에서 새어나가고 있다. 그러나 현재의 누수탐지 방법으로는 정확한 누수의 위치를 찾기 어렵고, 많은 비용을 투입하고 있지만 현실적인 제약사항이 많아 그 효과는 기대치에 이르지 못하고 있다. 본 논문은 TBR(Time Domain Reflectometer)을 이용한 누수탐지 기법으로 탐색한 누수위치 및 파이프 정보를 실시간으로 모니터링하여 빠른 복구를 가능하게 하고, 누수 비용을 줄일 수 있는 누수탐지 지리정보시스뎀(Geographic Information System)을 구축하였고, 누수탐지와 지리정보시스템의 모니터링 효율성을 높이기 위한 공간데이터베이스의 설계에 대하여 기술하였다. 또한 독립적인 형식으로 공간데이터베이스를 구축하여 서비스를 제공하는 기존 GIS들 사이에 다양한 종류의 지리정보를 효율적으로 활용하기 위해 OGC에서 제안한 GML(Geography Markup Language) 문서로의 변환에 관한 가능성을 검증하였다.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.309-315
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• 2009

Maintenance of adequate soil water content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement for precision irrigation would allow efficient supply of water to crops, thereby resulting in minimization of water drainage and contamination of ground water. This research reports on the characterization of spatial and temporal variations in water contents through three different textured soils, such as loam, sandy loam, and loamy sand, when water is applied on the soil surface using an one-line drip irrigation system and the soils are dried after the irrigation stops, respectively. Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30cm depths. Spatial variability in water content for each soil type was strongly influenced by soil textural class. There were big differences in wetting pattern and the rate of downward movement between loam and sandy loam soils, showing that the loam soil had a wider wetting pattern and a slower rate of downward movement than did the sandy loam soil. The wetting pattern in loamy sand soil was not apparent due to a low variability in water content (< 10%) by a lower-water holding capacity as compared to those measured in the loam and sandy loam soils, implying that the rate of water drainage below a depth of 30cm was high. When soils were dried, there were highly exponential relationships between water content and time elapsed after irrigation stops ($r^2$${\geq}$0.98). It was estimated that equilibrium moisture contents for loam, sandy loam, and loamy sand soils would be 17.6%, 6.2%, and 4.2%, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.336-336
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• 2022

빗물자원의 대부분은 바다로 유입되어 소모되거나, 하수로 유입되어 불필요한 고도처리 공정이 진행되고, 하수처리장 용량에 과부하를 발생시키는 등 막대한 예산이 투입되고 있는 실정이다. 갈수기시 농가에서 용수를 확보하기 위한 용수 운반장치 등 기반구축이 쉽지 않으며, 인력 부족으로 정상적인 용수공급에 어려움을 겪고 있다. 이에 빗물자원을 용수로서 효율적으로 활용하기 위한 시스템의 구축이 필요하다. 본 연구는 빗물저류조에 스마트 관수제어 시스템을 적용한 것으로 지중에 설치된 토양수분 센서와 저류조 내부의 수위 센서에서 관측된 데이터를 토대로 자동으로 지중에 수분을 공급하는 시설이다. 지중에 수분이 부족할 경우 밸브를 열어 자동으로 펌프를 가동시켜 저류조 내부의 물을 지중으로 공급시키며 지중의 수분이 충분하거나 저류조 내부의 물이 부족해질 경우 밸브를 닫아 공급을 중단하도록 한다. 또한 저류조의 수위와 토양의 수분량, 펌프의 작동여부 등은 앱을 이용하여 실시간으로 확인이 가능하며, 스마트폰 앱을 이용한 수동조작 또한 가능하다. 본 기술은 집수, 저류, 공급, 통신, 제어, 센서 총 6종의 모듈로 구성되어 있으며, 사용자의 환경 및 예산의 따라 집수, 저류, 공급 모듈 등 맞춤형 제품 구성이 가능하도록 개발하였다. 저류조의 물공급을 관리, 제어하는 시스템으로 센서로부터 전송받은 데이터를 기준으로 펌프를 작동시켜 수분공급을 제어할 수 있으며 해당 기록을 서버에 저장하여 데이터의 통계를 구할 수 있도록 하였다. 사용자가 앱을 통하여 직접적인 제어 및 가동환경에 대한 설정을 할 수 있어 사용자가 직접 현장에 오지 않아도 토지의 현황과 저류조의 수위, 수분 공급상황 등을 직접 제어할 수 있도록 개발하였다.