• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.321-327
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• 2006

In Korea, there is a growing competitive for water resources between industrial, domestic and agricultural consumer, and the environment as many other OECD countries. The demand on water use is also affecting aquatic ecosystems particularly where withdrawals are in excess of minimum environmental needs for rivers, lakes and wetland habits. OECD developed three indicators related to water use by the agriculture in above contexts : the first is a water use intensity indicator, which is expressed as the quantity or share of agricultural water use in total national water utilization; the second is a water stress indicator, which is expressed as the proportion of rivers (in length) subject to diversion or regulation for irrigation without reserving a minimum of limiting reference flow; and the third is a water use efficiency indicator designated as the technical and the economic efficiency. These indicators have different meanings in the aspect of water resource conservation and sustainable water use. So, it will be more significant that the indicators should reflect the intrinsic meanings of them. The problem is that the aspect of an overall water flow in the agro-ecosystem and recycling of water use not considered in the assessment of agricultural water use needed for calculation of these water use indicators. Namely, regional or meteorological characteristics and site-specific farming practices were not considered in the calculation of these indicators. In this paper, we tried to calculate water use indicators suggested in OECD and to modify some other indicators considering our situation because water use pattern and water cycling in Korea where paddy rice farming is dominant in the monsoon region are quite different from those of semi-arid regions. In the calculation of water use intensity, we excluded the amount of water restored through the ground from the total agricultural water use because a large amount of water supplied to the farm was discharged into the stream or the ground water. The resultant water use intensity was 22.9% in 2001. As for water stress indicator, Korea has not defined nor monitored reference levels of minimum flow rate for rivers subject to diversion of water for irrigation. So, we calculated the water stress indicator in a different way from OECD method. The water stress indicator was calculated using data on the degree of water storage in agricultural water reservoirs because 87% of water for irrigation was taken from the agricultural water reservoirs. Water use technical efficiency was calculated as the reverse of the ratio of irrigation water to a standard water requirement of the paddy rice. The efficiency in 2001 was better than in 1990 and 1998. As for the economic efficiency for water use, we think that there are a lot of things to be taken into considerations to make a useful indicator to reflect socio-economic values of agricultural products resulted from the water use. Conclusively, site-specific, regional or meteorogical characteristics as in Korea were not considered in the calculation of water use indicators by methods suggested in OECD(Volume 3, 2001). So, it is needed to develop a new indicators for the indicators to be more widely applicable in the world.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.33-36
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• 2002

The purpose of this study is to develope a indicator for agricultural water use. Agricultural water is challenged by the increase of water use in the sectors of urbanization and industry and social pressure to use water in sustainable and environmentally sound way. The development of agricultural environment indicators is divided into 13 sectors, among which agricultural water use indicators include amount and intensity of agricultural water use, efficiency of agricultural water use, shortage or surplus of water use, water stress, etc.. Agricultural water use indicators provide basic data for sustainable and environmentally sound agricultural development, and also help policy decision makers to solve water shortage problems through water policy and water management measures by making the most of the total available water resources.

• Journal of Korean Society of Rural Planning
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• v.25 no.4
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• pp.27-33
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• 2019

Agricultural water for crops are faced with the need to improve the use efficiency due to the impact of climate change. Water productivity (WP) is known as a good indicator for assessing resources efficiency. This study was conducted to assess WP of rice and potential water consumption (PWC) as new indicator for water use efficiency assessment. The average of WP was 0.7 kg/㎥, and Jeonbuk had the highest WP as 0.83 kg/㎥. Kangwon and Kyungbuk had the lowest WP as 0.59 kg/㎥. PWC showed the same trend because of rice consumption per capita, but Total PWC considering population living in each province showed the different trend with PWC. Every year, the changing patterns of WP was increasing little by little, and the patterns of PWC was decreasing greatly than WP. These results mean that WP has been slowly improved through breed development and irrigation techniques, and PWC was affected by reduced rice consumption and WP increasing. PWC could also be useful as an indicator to compare the water use efficiency between provinces or nations.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.159-165
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• 2019

BACKGROUND: The water footprint (WF) is an indicator of freshwater use that appears not only at direct water use of a consumer or producer, but also at the indirect water use. As an indicator of 'water use', the water footprint includes the green, blue, and grey WF, and differs from the classical measure of 'water withdrawal' because of green and grey WF. This study was conducted to assess and estimate the water footprint of the soybean and Chinese cabbage. METHODS AND RESULTS: APEX model with weather data, soil and water quality data from NAS (National Institute of Agricultural Sciences), and farming data from RDA (Rural Development Administration) was operated for analyzing the WF of the crops. As the result of comparing the yield estimated from APEX with the yield extracted from statistic data of each county, the coefficients of determination were 0.83 for soybean and 0.97 for Chinese cabbage and p-value was statistically significant. The WFs of the soybean and Chinese cabbage at production procedure were 1,985 L/Kg and 58 L/Kg, respectively. This difference may have originated from the cultivation duration. The WF ratios of soybean were 91.1% for green WF and 8.9% for grey WF, but the WF ratios of Chinese cabbage were 41.5% for green WF and 58.5% for grey WF. CONCLUSION: These results mean that the efficiency of water use for soybean is better than that for Chinese cabbage. The results could also be useful as an information to assess environmental impact of water use and agricultural farming on soybean and Chinese cabbage.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.246-253
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• 2019

Background: Water use efficiency (WUE) is an indicator of the trade-off between carbon uptake and water loss to the atmosphere at the plant or ecosystem level. Understanding temporal dynamics and the response of WUE to climatic variability is an essential part of land degradation assessments in water-limited dryland regions. Alternative definitions of and/or alternative methodologies used to measure WUE, however, have hampered intercomparisons among previous studies of different biomes and regions. The present study aims to clarify semantic differences among WUE parameters applied in previous studies and summarize these parameters in terms of their definition and methodology. Additionally, the consistency of the responses of alternative WUE parameters to interannual changes in moisture levels in Northeast Asia dryland regions (NADRs) was tested. Results: The literature review identified more than five different WUE parameters defined at leaf and ecosystem levels and indicates that major conclusions regarding the WUE response to climatic variability were partly inconsistent depending on the parameters used. Our demonstration of WUE in NADR again confirmed regional inconsistencies and further showed that inconsistencies were more distinct in hyper- and semi-arid climates than in arid climates, which might reflect the different relative roles of physical and biological processes in the coupled carbon-water process. Conclusions: The responses of alternative WUE parameters to drying and wetting may be different in different regions, and regionally different response seems to be related to aridity, which determines vegetation coverage.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.220-226
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• 2005

We investigated the effect of $O_3$ on the photosynthetic characteristics of oriental plane (Platanus orientalis L.) that is used as a side tree or ornamental tree in Korea. Two-year-old oriental plane seedlings were transplanted to pots and transferred into a closed $O_3$ chamber, Photosynthetic pigment content and photosynthetic characteristics of leaves were measured every three weeks during 100 ppb $O_3$ fumigation. There was no visible foliar injury by $O_3$ exposure and the content of photosynthetic pigments did not show significant differences between control and $O_3$-treated seedlings. But photosynthetic rate, stomatal conductance, and water use efficiency in leaves of $O_3$-treated seedlings were reduced after six weeks of ozone fumigation. In addition, reduction of carboxylation efficiency and photochemical efficiency was observed in leaves of $O_3$-treated seedlings after three weeks and six weeks. In accordance with our results, carboxylation efficiency, the most sensitive parameter to $O_3$ stress, was considered to be a suitable indicator of $O_3$ sensitivity.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.7
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• pp.688-693
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• 2009

In terms of water meter reading, the majority of 16 million houses use mechanical water meter in korea. So, a member of the utility's staff needs to access periodically the water meter and the value of the metered volume. However, due to the use of mechanical water meter, many issues have been appeared as cost, time, errors, accessibility, and readability. To settle these issues, we developed the walk-by meter reading system of digital water meter and outside indicator based on ubiquitous. And we could get the characteristics and the economical efficiency for water meter reading system. Thus, this study shows that the system can be widely used to the block system and the meter reading system for stable water supply.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.153-159
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• 2006

The discharges of time, technology and finance was increased and it was difficult to use water resources effectively by serious water pollutions. Thus the main aim of this work was focused on effectiveness of water treatment process using non-controlled indicators such as UV absorbance($E_{260}$) and particle counts that provided analytical results with simple and rapid. The soluble aluminum was increased by the increase of aluminum doses for turbidity removals It means that the water quality was not controlled by only turbidity monitoring cause maximum turbidity removal did not guarantee minimum residual aluminum in an aluminum-based coagulation. E removal efficiency appeared to be the promising indicator for monitoring the effectiveness of the water quality process such as coagulation and nanofiltration membranes for arsenic(V). On the basis of the particle monitoring, it was also found that the particle counts could be used very useful for changing the coagulants in real water treatments.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1063-1068
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• 2010

This study compared UV and UV/$H_2O_2$ inactivation of E.coli, a possible indicator microorganism for fecal contamination of water, and $Q{\ss}$ phage, an indicator for pathogenic viruses. UV inactivation of $Q{\ss}$, T4 and lambda phages in actual secondary effluent was investigated, too. As a result, similar inactivation efficiency between $Q{\ss}$ phage and E.coli was observed during UV treatment, while $Q{\ss}$ phage showed higher resistance to UV/$H_2O_2$ than E.coli. $Q{\ss}$ phage resistance to UV or UV/$H_2O_2$ does not reflect those of all pathogenic viruses. However, the result tells that the use of E.coli inactivation efficiency in evaluating microbiological safety of water could not always ensure the sufficient safety from pathogenic viruses. Meanwhile, $Q{\ss}$ phage showed less resistance to UV than T4 and lambda phages, indicating that the use of $Q{\ss}$ phage as an indicator virus may bring insufficient disinfection effectiveness by causing the introduction of lower UV dose than required. Consequently, it can be thought that T4 or lambda phages would be more desirable indicators in ensuring the sufficient disinfection effectiveness for various pathogenic viruses.

• Journal of Korea Water Resources Association
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• v.39 no.1 s.162
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• pp.59-68
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• 2006

To assess the water resources sustainability, many indicators and methodologies have been suggested by international organizations and developed in other countries. However, in the previous studies, some of indicators were unsuitable for assessing the sustainability of water use and management in Korea. Thus, in this study nSl(Water Resources Sustainability Index), a multi-variable index, was created by consideration of environmental, social, and economical criteria. Relative weights for components, indicators and sub-indexes, were determined by employing the Analytic Hierarchy Process. In order to extract the indicators related with water resources sustainability, the data related with water resources and indicators suggested in various field were compared and thoroughly reviewed. These indicators were classified into four groups; Economic Efficiency Index, Social Equity Index, Environmental Conservation Index, and Maintenance Capability Index. The weight of each component were decided by the survey of 127 specialists in water resources and sustainability. The result of survey represented that efficiency and equity of water use and water quality for river restoration are major issues in enhancing the water resources sustainability In addition, it was found that investment and public participation should be considered for sustainable water use.