• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.120-125
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• 2000

This study analyzes agricultural water demand nationwide which calculated by the estimation system for agricultural water demand(ESAD) with the data are observed in the other Studies. The results are as follows. Maximum, minimum and average values of annual evapotranspiration in paddy in 1,767 boundaries covering all the country are estimated as 819.2mm, 595.2mm and 702.9mm respectively. In the case of transplant seeding, the annual effective rainfall is estimated as 834.7mm to 464.3mm, while the average is 635.3mm. The amount of effective rainfall is largest in case of transplant seedlings and then come watered direct seeding and dry direct seeding regardless of region. Maximum, minimum and average values of annual evapotranspiration in upland in 1,767 boundaries are estimated as 659.97mm, 129.3mm and 411.8mm respectively. The annual effective rainfall is estimated as 607.2mm to 68.3mm while the average is 257.4mm. infiltration ratio in paddy in 1,767 boundaries applied in ESAD is 5.06mm/day in average, varying from 12.0mm/day to 2.0mm/day. Applied conveyance loss is 12.8% in average, varying from 18.0% to 8.0%.

• 한국물환경학회지
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• 제33권5호
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• pp.531-537
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• 2017

The biologic Oxygen Demand (BOD) is a reliable and generally accepted indicator of water pollution by organic pollutants. Accordingly, estimation of BOD export from paddies carries important implications fwith regard to water management in rural areas. In this study, hydrology and BOD concentration were monitored during the period 2008 through 2012, in an effort to understand the characteristics of BOD export from paddy fields. The findings demonstrated that BOD load by rainfall above 50 mm. occupied about 50 % of total load, whereas the load by less than ten mm. rainfall occupied about 29 % of the total load during periods of stormy activity. It therefore seems that it could be possible to reduce the BOD load up to 29 % during storm periods, when drainage control conducted for rainfall less than ten mm.(an amount which is relatively easy to manage). The documented mean loads of storm and non-storm were $17.1kg\;ha^{-1}\;yr^{-1}$ and $11.2kg\;ha^{-1}\;yr^{-1}$, respectively. The BOD load during the significant rainfall period was similar to the renewed unit load by NIER (2014). However, there were substantial differences between unit load and actual load when the non-storm load was incorporated into the BOD load estimation from paddy fields. In view of the foregoing, it is felt that, the non-storm load needs to be further considered and managed for the successful implementation of Total Maximum Daily Load (TMDL) program.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2005년도 국제학술회의
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• pp.75-87
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• 2005

Remote sensing(RS)- and geographic information system(GIS)-based information management to measure and assess agri-environment schemes, and to quantify and map environment indicators for nature and land use, climate change, air, water and energy balance, waste and material flow is in high demand because it is very helpful in assisting decision making activities of farmers, government, researchers, and consumers. The versatility and ability of RS and GIS containing huge soil database to assess agricultural environment spatially and temporally at various spatial scales were investigated. Spectral and microwave observations were carried out to characterize crop variables and soil properties. Multiple sources RS data from ground sensors, airborne sensors, and also satellite sensors were collected and analyzed to extract features and land cover/use for soils, crops, and vegetation for support precision agriculture, soil/land suitability, soil property estimation, crop growth estimation, runoff potential estimation, irrigated and the estimation of flooded areas in paddy rice fields. RS and GIS play essential roles in a management and monitoring information system. Biosphere-atmosphere interection should also be further studied to improve synergistic modeling for environment and sustainability in agri-environment schemes.

• 한국수자원학회논문집
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• 제50권7호
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• pp.503-511
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• 2017

수자원 계획 및 운영을 위한 수요량을 추정하는데 있어, 실제 이용 추세를 반영한 생활용수나 공업용수와 달리 농업용수는 용수공급시설의 규모를 결정하기 위한 방법론이 주로 적용되어 왔다. 이는 불가피하게 농업용수의 과다추정으로 이어질 수 있으며, 전체 수자원 계획의 관점에서 각 용도별 용수 수급계획의 불균형을 초래할 수 있다. 본 연구에서는 기존 방법론과 비교하여 순물소모량 개념의 접근방법의 차이에 대해 고찰하였으며, 이를 제주도 전역에 적용하여 농업용수 수요량 특성을 분석하였다. 수요량 산정에 핵심적인 인자인 증발산량의 정확한 추정을 위하여 SWAT 모형을 적용하고, 제주도 지역의 지형 및 기상, 유출, 물이용 특성을 반영한 유역 모델링을 수행하였으며, 기존 물수지 결과와 비교하여 모델링 자료의 신뢰성을 평가하였다. 과거기간(1992~2013년)에 대해 제주도 전체의 수요량은 연간 427 mm로 분석되었으며, 동부와 서부 해안지역을 중심으로 상대적으로 높은 수요량을 나타내었다. 유역면적 $30km^2$ 이상인 10개 하천유역에 대해서도 연평균 수요량 및 계절별 변화 특성을 분석하였다. 또한, 장래 2020년 지역별 작물재배면적을 적용하여 10년 빈도 가뭄에 대응한 수요량을 산정한 결과 기존 제시된 수요량 대비 54% 수준으로 나타났다. 이는 수요량 산정목적에 따른 접근방법의 차이로 인해서 나타난 결과로서, 수자원 관리 및 운영의 관점에서 보면 순물소모량만큼의 추가적인 수요가 예상되지만, 실제 공급의 관점에서는 기존 수요량만큼의 시설계획이 필요하다고 판단할 수 있다. 본 연구에서 적용된 방법론 및 결과의 실무 활용을 위해서는 공학적인 검증은 물론이고 정책적 제도적인 측면에서의 합리적인 논의가 필요할 것이다.

• 한국농공학회논문집
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• 제57권2호
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• pp.85-92
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• 2015

Since the consumption of the livestock products increased for the past 10 years in Korea, the water use for live animals has become more important in terms of water savings. Therefore, the index connecting water use and livestock products consumption should be required for sustainable water management, and water footprint concept could be suggested as the index. The aim of this study is to estimate the water footprint for livestock products; beef cattle, swine, and broiler chicken. The water footprint for livestock products is divided into direct and indirect water. The direct water includes the drinking and servicing water, and the indirect water includes the water for the cultivation of feed crops. The water footprint of beef cattle was calculated to $17,023.1m^3/ton$, and direct water was $91.2m^3/ton$, and indirect water was $16,931.9m^3/ton$. The water footprint of swine was calculated to $4,235.8m^3/ton$, and direct water was $129.7m^3/ton$, and indirect water was $4,106.0m^3/ton$. The water footprint of broiler chicken was calculated to $2,427.7m^3/ton$, and direct water was $7.6m^3/ton$, and indirect water was $2,420.1m^3/ton$. Also, we compared the water footprint to water demand of water vision 2020 which is the main report for national water management. The water vision 2020 reported only direct water for live animal, but the water footprint includes the direct and indirect water. Therefore, the water footprint could be applied to various fields relating water and food.

• 한국농공학회논문집
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• 제55권3호
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• pp.1-7
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• 2013

The dam plan quantity of constructive and water supply quantity of present time are showing a difference with change in climate and augmentation of water demand for multipurpose dams in Nakdong river basin. But revaluates a water supply ability the method or the process is official for is not taking a position, so actual condition applies the plan quantity of dam constructive. Considers various situation of actual multipurpose dam from research sees consequently and in K-WEAP is an integrated water resources evaluation plan model applies as water permit availability multipurpose dam, currently water permit availability comparison, analyzed. In this study, the natural daily flow data and apply the dimensions of the reservoir, and for more than 30 years of the long-term water balance analysis conducted by Date Nakdong river basin can supply reservoirs are large quantity of permits available is presented.

• 한국물환경학회지
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• 제27권5호
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• pp.625-633
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• 2011

A long-term water quality monitoring in the Han River Basin reveals a consistent increasing trend for the concentration of refractory organic matter (R-OM) in major monitoring sites of the watershed. Because the determination of R-OM concentrations typically requires a long time of microbial incubation, it is essential to present the estimation indices for R-OM for an efficient watershed management. In this study, a number of surface water samples were classified into three groups, each of which were collected from Lake Paldang, rivers at rain and non-rain events, respectively. The corresponding R-OM concentrations were correlated with biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) concentrations as well as ultraviolet and fluorescence intensities of the filtered samples. Among the traditional organic matter parameters, TOC exhibited the highest correlation coefficient with the R-OM concentrations regardless of the types of the sample groups. The equations for conversing TOC into R-OM concentrations were finally suggested as $0.43{\times}TOC+1.12$, $0.44{\times}TOC+0.61$, $0.24{\times}TOC+1.28$ for river samples at rain and non-rain events, and lake samples, respectively. TOC-BOD(C), the values of the TOC concentrations subtracted by carbon-converted BOD concentrations, was a good index for estimating the absolute concentrations of R-OM. UV absorbance at 254 nm was well correlated with R-OM concentrations of river samples while fluorescence intensities at 350 nm showed an excellent relationship with R-OM concentration of the lake samples. Our results suggests that simple spectroscopic parameters could be applied for in-situ monitoring tool techniques in watersheds.

• 자원ㆍ환경경제연구
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• 제11권4호
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• pp.633-657
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• 2002

This study presents a demand modelling for landfill gas, which is used as alternative energy source for district cooling business. By analyzing the cost minimizing behavior of producer facing with three alternative energy sources such as electricity, cooling heat water, and gas, a demand function for landfill gas is derived from the optimal operating time of gas fired production facility, and estimated using unpublished data, which are associated with Seoul city's development plan for Sang-am area. The estimation results repeals that Seoul City could supply the land-fill gas of 13.76 million cubic meters each year at the price of about 16 won per cubic meters. However, if the investment costs associated with installation of gas collecting facilities are treated as sunk costs, annual amount of gas supplied is expected to increase to 14.22 million cubic meters at a lower unit price of 14.76 won.

• 한국농공학회논문집
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• 제53권4호
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• pp.39-47
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• 2011

The aim of the study is to predict potential evapotranspiration and crop water requirement using meteorological data from MIROC3.2 with A1B scenario. Increase of evapotranspiration due to temperature rise can be observed out of the analysis, while effective rainfall decreased. The evapotranspiration elevation results in large amount of crop water requirement in the paddy farming. It can be seen that rainfall intensification at non-irrigation period brings effective rainfall decrease, while contributes to higher demand of crop water at irrigation period. It is necessary to secure additional water resources to adapt the climate change. It is expected that estimation on potentialevapotranspiration in this study can be used for formulation of master plan of water resources.

• 한국농공학회논문집
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• 제60권2호
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• pp.45-53
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• 2018

Demand for essential resources including water, energy and food is rapidly increasing due to climate change, population growth and urbanization. To solve this problem, the concept of water-energy-food nexus has been introduced, and many countries have been trying to acquire the Nexus technology that can maximize the efficiency by analyzing the interconnection between resources. In this regard, this study attempted to estimate the probable maximum water thermal energy in the dam based on the water-energy nexus concept. The estimation of the probable maximum water thermal energy was implemented to monthly water storage of the largest dams in the four major river systems. As a result of analyzing the estimated monthly water thermal energy from 2000 to 2016, Soyang River dam has the largest probable maximum water thermal energy, and Sumjin River dam has the smallest. However, the probable maximum water thermal energy was small in common between March and April, between September and October due to the small temperature difference between the ambient air and the dam water. Also, according to the characteristics of the dam, Daecheong dam and Soyang River dam were beneficial for supplying water thermal energy for heating, and Sumjin River dam and Andong dam were advantageous for supplying water thermal energy for cooling. Our findings can be useful to realize the water-energy-food nexus by increasing the utilization and value of water resources as well as expanding the roles and functions of dams as a starting point to use dam water thermal energy.