• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.165-170
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• 2011

Recently natural disasters such as the frequency and intensity of drought have been increasing as a result of climate change. This study suggests a drought index, WADI (Water Availability Drought Index), that considers water availability using 6 components (water intake, groundwater level, agricultural reservoir water level, dam inflow, streamflow, and precipitation) using the Z score and data monitoring on a nationwide level. SPI (Standardized Precipitation Index) was applied in coastal area. For the severe droughts of 2001 spring and 2008 autumn, the index was evaluated by comparison with reported damage areas. suggested to combine The spatial concordance rate of WADI in 2001 and 2008 for estimation of the degree of drought severity was 50 % and 24 % compared to the actual recorded data respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.6-12
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• 2010

일반적으로 가뭄은 기상학적 가뭄, 농업적 가뭄, 수문학적 가뭄의 유형 등으로 분류한다. 본 연구에서는 우리나라에 적합한 수문학적 가뭄 지수인 물가용지수(Water Availability Index)를 개발하였다. 또한 다각적인 가뭄평가를 위해 기상학적 가뭄의 평가할 수 있는 표준강수지수(Standard Precipitation Index)와 농업적 가뭄을 평가할 수 있는 토양수분지수(Soil Moisture Index) 그리고 개발한 물가용지수(Water Availability Index)를 지수의 가뭄에 대한 등급을 통일시키기 위해 새롭게 산정하였다. 또한 기상청에서 제시하고 있는 월간기상정보 자료를 이용하여 가뭄전망을 할 수 있는 기법을 개발하였다.

• Journal of Wetlands Research
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• v.13 no.1
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• pp.35-44
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• 2011

In order to explore vegetation adaptation to climate variability and the impacts on water balance dynamics, the inter-regional and the inter-annual variability of both water availability and vegetation productivity are investigated. The Horton index, which is the ratio between actual evapotranspiration and catchment wetting as a measure of vegetation water use at catchment-scale, is revisited to quantify the effects of growing-season water availability on hydrologic partitioning at catchment scale. It is shown that the estimated Horton index is relatively constant irrespective of inter-annual climate variability. In addition, the Horton index is compared with catchment-scale vegetation rain use efficiency. The results show that there is an interesting pattern in the response of vegetation water use to water availability. When water becomes the limiting factor for vegetation productivity, the catchment-scale vegetation rain use efficiency converges to a common maximum value in agreement with earlier findings at the ecosystem level.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.93-103
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• 2018

The aim of this study is to apply the Water-Energy-Food-Land Nexus approach which can analyze the trade-offs among resources, and assess the holistic impacts of food security. First, we applied rice as a study crop and analyzed the trend of consumption of rice and the area of paddy fields. Second, the portfolios of water, energy, and land for rice production were constructed using data of footprints and productivity. Finally, the self-sufficiency ratio (SSR) of rice in target year was set as food security scenario and assessed the impacts of food security on water, energy, and land availability. In 2030, the SSR of rice decreased to 87 %, and water use for producing rice decreased from 4,728 to $3,350million\;m^3$, and the water availability index increased from 0.33 to 0.53. However, food security is essential issue and we set the 50 % and 100 % SSR of rice as high and low food security scenarios. For 100% SSR in 2030, about $3,508million\;m^3$ water was required and water availability index reached to 0.5. In other words, there is the trade-off between food security and water-energy-lands availability. Therefore, it is difficult to make a decision whether a high level of SSR is better or worse. However, this study showed the both positive and negative impacts by change of food security and it can be useful for setting the policy decision considering both food security and sustainable resource management at the same time.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.458-458
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• 2022

It is essential to reduce global carbon emissions, mainly from energy use. The water supply and distribution sector is a vital part of human society and is one of the primary energy consumers. The procurement and distribution of water require electricity to operate the pump to deliver water to users with sufficient pressure. As the water users are spatially distributed over a wide area, the energy required to deliver water to each user differs depending on the corresponding supplying element (reservoir, tank, pipe, pump, and valve). This difference in energy required for each user also comes with a difference in pressure availability which affects the level of service for individual users and the whole network. Typically, there is a disproportion where users close to the source experience excessively high pressure with low energy consumption. In contrast, remote users need more energy to get the minimum pressure. This study proposes the Energy Return Index (ERI) to quantify the pressure return from particular energy consumption to supply water to each node. The disproportionality can be quantified and identified in the network using the proposed ERI. The index can be applied to optimize the network elements such as pump operation and tank location/size to reach a balanced energy consumption with the appropriate level of service.

• KIEAE Journal
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• v.9 no.3
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• pp.21-27
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• 2009

The goal of this paper is to determine the suitability evaluation indices of a riverside reservoir space planning by classifying major indicators and calculating AHP(Analytical Hierarchy Process) based weights of them. The major indicators were set up based on literature review and questionnaire survey to experts. Four indicator categories were developed: location, environment, resource availability and economical efficiency. And they were divided into 12 sub-categories for calculating AHP-based weights. First, as for the major indicator categories, the calculation shows that the weighted index of environment is the most important at 0.458, followed by location at 0.128, economical efficiency at 0.170 and resource availability at 0.154. This suggests that environment is getting more public attention and the reservoir is regarded as a facility that is connected to a river. Those weight values were considered in calculating final weights for each of 12 sub-categories. Among them water quality and ecological environment take top ranks at 0.190 and 0.186, respectively. The lower ranks include access 0.112, resource availability of site 0.082, tourism resource 0.078, users 0.076, available land 0.052, area of site 0.031, shape of site and deterioration level 0.030 and percentage of private land 0.030 - which represents general considerations in other space planning. The difference of the top rank (water quality, 0.190) and the last one (percentage of private land, 0.027) is 0.163. The above result shows that users regard environmental aspect and resource availability more important than easiness of construction.

• Journal of Environmental Policy
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• v.10 no.4
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• pp.61-80
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• 2011

Through concentrated investments in environmental regulations centered around BOD, which is a biodegradable matter index, and basic environmental infrastructures, national BOD pollution level has continuously improved. Nonetheless, limitations of BOD management system has become evident through nation-wide stagnation and/or increases of refractory organic matters, such as COD, at main drinking water sources, and the need for a new index, which can easily indicate different environmental conditions, has increased. Therefore, this study suggests a new organic management index for a proper management of surface water. $COD_{Cr}$ and TOC were examined as candidates for surface water quality management index, and it was found that TOC was more appropriate than $COD_{Cr}$ as an organic matter management index. Through this study, it was found that TOC possesses following qualities: a more representative index; international acceptability; monitoring program is easier; better availability of analysis techniques; better accuracy and precision of analysis; less time required for analysis; ease of operation; management of disinfection byproducts; connection with present policies; existence of foreign and domestic application case studies; and correlation with water ecosystem.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.3
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• pp.115-123
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• 2008

Evapotranspiration mapping using both meteorological ground-based measurements and satellite-derived information has been widely studied during the last few decades and various methods have been developed for this purpose. It is significant and necessary to estimate regional evapotranspiration (ET) distribution in the hydrology and water resource research. The study focused on analyzing the surface ET of Chungbuk region using Landsat 7 ETM imagery. For this process, we estimated the regional daily evapotranspiration on May 8, 2000. The estimation of surface evapotranspiration is based on the relationship between Temperature Vegetation Dryness Index (TVDI) and Morton's actual ET. TVDI is the relational expression between Normalized Difference of Vegetation Index (NDVI) and Land Surface Temperature (LST). The distribution of NDVI corresponds well with that of land-use/land cover in Chungbuk. The LST of several part of city in Chungbuk region is higher in comparison with the averaged LST. And TVDI corresponds too well with that of land cover/land use in Chungbuk region. The low evapotranspiration availability is distinguished over the large city like Cheongju-si, Chungju-si and the difference of evapotranspiration availability on forest and paddy is high.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.427-441
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• 2011

This study developed the Climate Variability Index (CVI) to assess the water resources through adding detail indicators into the existing regional Water Poverty Index (WPI) to consider climate variability and flood damage. This study aims at selecting indicators of WPI focused on water availability and regional climate variability, assessing regional variability of the indices during 1998-2007, and providing information to help determining the priority of water sector policies, investment, and applications. The WPI represents the relationship between the level of welfare and the water use. Considered with flood management and climate variability, CVI added by regional characteristics may be used in water resources management as well as flood mitigation for coping with climate change.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.5
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• pp.127-136
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• 2017

The object of this study was to assess availability of meteorological drought index for agricultural dorught estimation in ungauged area of agricultural drought parameters which are reservoir water level and soil moisture. The IADI (Integrated Agricultural Drought Index) and the SPI (Standard Precipitation Index), which are the criteria for determining agricultural drought and meteorological drought, were calculated and compared. For this purpose, the droughts that occurred in the Baeksan reservoir in Gimje and the Edong reservoir in Suwon were evaluated by using the IADI and SPI drought indecies. In addition, we compared and analyzed the depth of drought based on the two drought indices. Evaluations derived form the IADI and SPI showed that the standard precipitation index tended to indicate the occurrence of drought earlier than the integrated agricultural drought index. However, the integrated agricultural drought index was better than the standard precipitation index at evaluating the severity of drought during the period of irrigation. The relationship between these two drought indices seems to be useful for decision making in the case of drought, and it is considered that more studies are needed to examine the applicability of these drought indexes.