• Journal of Environmental Impact Assessment
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• v.17 no.4
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• pp.235-242
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• 2008

To develop a watershed management plan for protection of the lake water quality, the linkages among land use activities, stream water quality, and lake water quality must be understood. This study conducted to develop a Decision Support System(DSS) for the reservoir water quality managers and a comprehensive watershed management plan. This DSS has three main components; database, interactive decision model, and data delivery interface system. Graphic User Interface(GUI) was developed as the interface medium to deliver the data and modeling results to the end users. Water quality management scenarios in Yongdam reservoir consist of two parts. One is the watershed management, and the other is water quality management in the reservoir. The watershed management scenarios that were evaluated include as follows : a removal of point sources, control of waste water treatment plant, reductions in nonpoint sources, and the management of developed land. Water quality management scenarios in the reservoir include to install a curtain wall and to operate an algae removal system. The results from the scenario analysis indicate that the strategy of the reservoir water quality management can promise the best effectiveness to conserve the quality of reservoir water. It is expected that many local agencies can use this DSS to analyze the impact of landuse changes and activities on the reservoir watershed and can benefit from making watershed management decisions.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.5
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• pp.447-457
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• 2017

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.294-294
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• 2022

In 2013, the Asian Development Bank classified the Philippines among the countries facing high food security risks. Evidence has suggested that climate change has affected agricultural productivity, and the effect of extreme climatic events notably drought has worsened each year. This had resulted in serious hydrological repercussions by limiting the timely water availability for the agriculture sector. Laguna is the 3^rd most populated province in the country, and it serves as one of the food baskets that feed the region and nearby provinces. In addition to climate change, population growth, rapid industrialization, and urban encroachment are also straining the delicate balance between water demand and supply. Studies have projected that the province will experience less rainfall and an increase in temperature, which could simultaneously affect water availability and crop yield. Hence, understanding the composite threat of climate change for crop yield and water consumption is imperative to devise mitigation plans and judicious use of water resources. The water footprint concept elaborates the water used per unit of crop yield production and it can approximate the dual impacts of climate change on water and agricultural production. In this study, the water footprint (WF) of six main crops produced in Laguna were estimated during 2010-2020 by following the methodology proposed by the Water Footprint Network. The result of this work gives importance to WF studies in a local setting which can be used as a comparison between different provinces as well as a piece of vital information to guide policy makers to adopt plans for crop-related use of water and food security in the Philippines.

• Economic and Environmental Geology
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• v.47 no.3
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• pp.219-225
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• 2014

In Korea, there are 1,474 thousand pumping wells nationwide which account for about 12% of total water use in 2012. As much as 39 hundred million tons of groundwater were used while 333 hundred million tons of total water were supplied in 2012. Because the water management authority projects that water demand will exceed supply by 2021, the authority is planning to extensively expand groundwater use in accordance with economic feasibility. Using the basic frameworks of cost-benefit analyses of the World Bank and the US Environmental Protection Agency (US EPA), the objective of this study is to examine the costs and benefits of the expansion of Korea's groundwater extraction through pumping wells. We conclude that the BC ratio of the groundwater pumping wells is 2.98. This signifies that the benefits are 2.98 times higher than the costs. The benefits include use and non-use values of pumping wells while the costs include the installation and maintenance of new wells, in addition to the restoration and pollution costs of abandoned wells, as well as fees for water quality tests, etc.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2015.11a
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• pp.479-487
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• 2015

In Korea, there are 1,474 thousand pumping wells nationwide which account for about 12% of total water use in 2012. As much as 39 hundred million tons of groundwater were used while 333 hundred million tons of total water were supplied in 2012. Because the water management authority projects that water demand will exceed supply by 2021, the authority is planning to extensively expand groundwater use in accordance with economic feasibility. Using the basic frameworks of cost-benefit analyses of the World Bank and the US Environmental Protection Agency (US EPA), the objective of this study is to examine the costs and benefits of the expansion of Korea's groundwater extraction through pumping wells. We conclude that the BC ratio of the groundwater pumping wells is 2.98. This signifies that the benefits are 2.98 times higher than the costs. The benefits include use and non-use values of pumping wells while the costs include the installation and maintenance of new wells, in addition to the restoration and pollution costs of abandoned wells, as well as fees for water quality tests, etc.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.423-428
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• 2013

Although closed soilless culture is useful for saving water and fertilizers with minimizing environmental pollution, adequate management of nutrient solutions is still not stabilized in greenhouse cultivation. In order to investigate the problems occurred in closed soilless culture of Paprika (Capsicum annuum L., cv. Fiesta), we compared ion balance, fruit yield, and the water and fertilizer use efficiencies in the closed system with those in the open system. The plants were grown in rockwool culture with a nutrient solution of EC $2.5dS{\cdot}m^{-1}$. After 4 weeks of treatment, individual ratio of $NO{_3}^-$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$ to total ion concentrations ($meq{\cdot}L^{-1}$) decreased from the initial value, especially the biggest decrement was observed in $K^+$, and on the other hand, $SO{_4}^{2-}$, $Cl^-$, and $Na^+$ were accumulated in the closed system. Yields after four-time harvests were 19% higher in the open system than in the closed system. Total volume of water used per unit area ($m^2$) in the open system was 20% higher, but the total water use per fruit was not significantly different between the two systems, while t total fertilizer use per fruit was 78% higher in the closed system. Amount of marketable fruits was not significantly different between the two systems. We concluded that the increase in $K^+$ supply and the replenishment of recycled nutrient solution every four weeks were required for preventing the imbalance or depletion of nutrients in the close soilless culture of paprika plants to get more balanced nutrient composition during whole cultivation period.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.6
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• pp.43-51
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• 2013

This study aims to examine the presence of non-stationary relationship between water quality and land use in watersheds. In investigating the relationships between land use and water quality, most previous studies adopted OLS method which is assumed stationarity. However, this approach is difficult to capture the local variation of the relationships. We used 146 sampling data and land cover data of Korean Ministry of Environment to build conventional regressions and GWR models for BOD, TN and TP. Regression model and GWR models of BOD, TN, TP were compared with $R^2$, AICc and Moran's I. The results of comparisons and descriptive statistics of GWR models strongly indicated the presence of Non-Stationarity between water quality and land use.

• Journal of Food Hygiene and Safety
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• v.23 no.2
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• pp.98-107
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• 2008

The ozone has the oxidizing power which is powerful the fluorine and the antimicrobial spectrum of wide scope. Researches were carried out to use the merits that ozone has in various fields including the food industry, and many studies are also conducted nowadays for more efficient use of ozone. The ozone was permitted legally as a food additive and was practically used in the United States, Australia, Japanese etc. In November 2007, ozone water was permitted as a food additive in Korea and the interest in the use of ozone water has been on the rise in the Korea's food industry. As a olisinfectant method, ozone has many advantages. The maintenance and management expenses of ozone are lower than the installation cost at early stages and no by-products are generated after use it compared to others. Recently the demand of ozone as a olisinfectant method is increasing drastically. Although ozone water is popularly used to sterilize raw foods like fruits, vegetables and meats, the cases are still limited and were verified by the survey results. However, the use of ozone water is gradually being increased and is focused on food services. Ozone water refers to a state where ozone is dissolved into water to more conveniently use ozone. Accordingly, ozone water should be managed in regards with the amount and time of water-dissolved ozone, and the control of discharged ozone concentration is required for safe use of ozone water. The items to control mentioned above are directly related to the performance of the devices, and therefore, it is required to newly establish the performance criteria of ozone water manufacturing devices.

• 수도
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• v.24 no.5 s.86
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• pp.29-44
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• 1997

Sewage sludge produced in Korea was 1,275,800 tons (dewatered sludge cake) per year in 1996, which is 3,495 tons per day, 0.303% of 11,526,100 tons per day of sewage treated in 79 sewage treatment plants. Sludge production has been and will be increasing in accordance with construction of new facilities for sewage treatment. Most of the sludge is currently disposed by landfill and ocean dumping, but it is becoming difficult to find suitable sites for landfill, particularly in big cities such as Seoul. In addition, rapid increase of landfill cost is anticipated in a near future. Current trend for sludge disposal in advanced countries is land application. Over the past 10 to 20 years in the United States, sludge management practices have changed significantly, moving from disposal to beneficial use. They use biosolid for utilization instead of sludge for disposal. Under the Clean Water Act of 1972, amended in 1987 by Congress, the U.S. EPA was required to develop regulations for the use and disposal of sewage sludge. The EPA assessed the potential for pollutants in sewage sludge to affect public health and the environment through a number of different routes of exposure. The Agency also assessed the potential risk to human health through contamination of drinking water sources or surface water when sludge is disposed on land. The Final Rules were signed by the EPA Administrator and were published (Federal Register, 1993). These rules state that sewage sludge shall not be applied to land if the concentration of any pollutant in the sludge exceeds the ceiling concentration. In addition, the cumulative loading rate for each pollutant shall not exceed the cumulative pollutant loading rate nor should the concentration of each pollutant in the sludge exceed the monthly average concentration for the pollutant. The annual pollutant loading rate generally applies to applications of sewage sludge on agricultural lands. The most popular beneficial use of sewage sludge is land application. The sludge has to be stabilized for appling to land. One of the stabilization process for sewage sludge is lime stabilization process. The stabilization process is consisted of the stabilizing process and the drying process. Stabilization reactor can be a drum type reactor in which a crossed mixer is equipped. The additive agents are a very reactive mixture of calcium oxide and others. The stabilized sludge is dried in sun drier or rotary kiln.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.1 s.1
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• pp.171-180
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• 1993

Concern about nonpoint source pollution associated with urban storm water has led to the development of new tools for better water quality planning. This paper presents an application of a geographic information system (GIS) for urban water quality study. The GIS was used to manage land use data for nonpoint source pollution modeling and to aggregate pollutant loadings within various types of geographic units. An empirical water quality model was used to estimate pollutant loadings based primarily on land use. A land use coverage was created by updating an old coverage through interpretation of recent photography. This land use coverage was also used to record all pollutant loadings for each land use polygon. Storm sewer maps were digitized and interpreted to create a coverage of storm sewer basins and sub-basins. By overlaying pollutant loadings with the sewer sub-basin layer, aggregated pollutant loadings for major sewer outfalls were calculated. Based on the loading information, critical areas of excessive pollutant loadings were located and the effectiveness of Best Management Practices (BMPs) to control pollutant loadings were evaluated.