• Journal of Korea Water Resources Association
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• v.54 no.10
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• pp.769-777
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• 2021

This study investigated the change of the achievement rate of the target water quality conditioned on the occurrence of severe drought, to assess the effects of meteorological drought on the water quality management in the Nakdong River basin. Using three drought indices with difference time scales such as 30-, 60-, 90-day, i.e., SPI30, SPI60, SPI90, and three water quality indicators such as biochemical oxygen demand (BOD), total organic carbon (TOC), and total phosphorus (T-P), we first analyzed the relationship between severe drought occurrence water quality change in mid-sized watersheds, and identified the watersheds in which water quality was highly affected by severe drought. The Bayesian network models were constructed for the watersheds to probabilistically assess the relationship between severe drought and water quality management. Among 22 mid-sized watersheds in the Nakdong River basin, four watersheds, such as #2005, #2018, #2021, and #2022, had high environmental vulnerability to severe drought. In addition, severe drought affected spring and fall water quality in the watershed #2021, summer water quality in the #2005, and winter water quality in the #2022. The causal relationship between drought and water quality management is usufaul in proactive drought management.

• Journal of Korean Society on Water Environment
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• v.34 no.6
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• pp.591-601
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• 2018

Optimized BMP plans for controlling water quality using the Pareto trade-off surface curve in upper basin of Namgang Dam is proposed. The proposed alternatives consist of BMP installation scenarios in which the reduction efficiency of non-point pollutants is maximized in a given budget. The multi-objective optimization process for determining the optimal alternatives was performed without direct implementation of a watershed model such as SWAT analysis, thereby reducing the time taken. The shortening of the calculation time further enhances the applicability of the multi-objective optimization technique in preparing regional water quality management alternatives. In this study, different types of BMP are applied depending on the land use conditions. Fertilizer input control and vegetative filter strip are considered as alternatives to applying BMP to the field but only control of fertilizer input can be applied to rice paddies. Fertilizer input control and vegetative filter strip can be installed separately or simultaneously in a hydrologic response unit. Finally, 175 BMP application alternatives were developed for the water quality management of the upper river basin of Namgang dam. The proposed application alternative can be displayed on the map, which has the advantage of clearly defining the BMP installation location.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.376-385
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• 2007

Construction project is necessary element for human life to upgrade the quality and convenience. However, due to its contradictory nature to the environment preservation, environmental pollution and damage, deterioration of natural scenery, noise/vibration, water quality pollution, etc. caused in the process of construction greatly affect the environment. For the building or construction project, its possible impact on environment during construction work and after completion must be predicted at its design phase, which will result in the completion of the architecture convenient for human being with its environmental pollution reduced to minimum level. In this study, the checklist of environmental factors was suggested, which should be taken into account at its design phase in conducting the construction work. Proposed checklist was linked with the developed web-based system for the convenience of users like designer and construction manager, etc. It is expected that the checklist suggested by this study will help the designer and construction manager to continue the steady development from the environmental viewpoint during the design phase.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.219-227
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• 2012

Daily solar radiation is essential for water resources planning and environmental impact assessment. However, radiation data is not commonly available in Korea other than in big cities, and there has been no direct measurement for rural areas where water resources planning and environmental impact assessment is usually most needed. In general, missing radiation data is estimated from nearby regional stations within a certain distance, and this study compared two dominant methods (modified Angstrom equation and transmittance interpolation method) at six stations in Nakdong River watershed area. Two methods shows a similar level of accuracy but the transmittance interpolation method is likely to be superior in that there is no need for any measurement element since the modified Angstrom equation require the sunshine hour measurement. This study will contribute to improve water resource and water quality management in Nakdong River watershed.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.441-450
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• 2007

본 연구는 humic acid 및 bromide를 함유한 상수 원수에 오존 처리를 수행함에 있어 수질 특성 및 공정조건에 따른 bromate 및 formaldehyde 의 생성을 고찰하였다 . 회분식 실험장치를 이용하여 오존의 주입농도, DOC 농도, bromide 농도, pH, 알칼리도 및 반응 시간을 변화시키면서 오존처리 시 생성되는 대표적인 부산물인 bromate 및 formaldehyde의 거동을 파악하였다. 본 연구에서 검토된 영향 인자 중 수중의 pH조건은 bromate 및 formaldehyde의 생성에 가장 중요한 인자로 나타났다. DOC(dissolved organic carbon) 농도가 증가할수록 bromate 생성은 감소하였고 formaldehyde 의 생성은 증가하였다. 오존처리를 통해 UV254 는 효율적으로 감소되었고, UV254의 감소율 및 오존 농도는 선형 관계를 나타냈다.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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• pp.13-21
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• 2008

With the rise in membrane applications, residuals management has become a growing challenge for membrane system. The primary residuals of MF/UF (microfiltration/ultrafiltration) system results from the wastes generated during backwashing. Many regulatory agencies, utilities, and water process engineers are unfamiliar with the characteristics and methods for treatment and disposal of membrane residuals. Therefore, this study was performed to investigate the backwash residuals water quality from the pressurized system with and without pre-coagulation, and to suggest approaches for the backwash residuals treatment. Pressurized MF system was installed at Guui water intake pumping station and operated with raw water taken from the Han River. We compared performances with and without the recycling backwash residuals at flux conditions, 50 LMH and 90 LMH with and without pre-treatment (coagulation). Based on the results, recycling of backwash residuals in pressurized system with pre-coagulation showed applicability of backwash residuals managements. Moreover, the recovery rate also increased up to over 99%.

• Journal of Korean Society on Water Environment
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• v.27 no.3
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• pp.357-363
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• 2011

In spite of numerous advantages in railroads such as mass transportation, high reliability, and environmental soundness etc., the value of railroad construction is relatively underestimated compared to road. This is because the current method of evaluation focuses mainly on economic effect. In this study, considering recent research results, the environmental value of railroad construction was assessed by calculating the effect of reduction of emissions and water contamination. With these two benefits, the environmental effect produced by railroads and road construction was calculated and compared to each other using EMME/3. As a result, the senario 4 which considers 'Hot/Cold start' condition and water contamination had highest benefits. Furthermore, the environmental effect produced by railroad is 55~101% higher than road construction. If the suggested method is used in the current appraisal system, the environment-friendly mode like railway would be highly valued, much more than before.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.3
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• pp.39-51
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• 2024

To effectively implement the integrated water management policy outlined in the National Water Management Act, it is essential to analyze agricultural water supply and demand at both basin and water district levels. Currently, agricultural water is primarily distributed through open canal systems and controlled by floodgates, yet the utilization-to-supply ratio remains at a mere 48%. In the case of agricultural water, when analyzing water balance through existing national basin water resource models (K-WEAP, K-MODISM), distortion of supply and regression occurs due to calculation of regression rate based on the concept of net water consumption. In addition, by simplifying the complex and diverse agricultural water supply system within the basin into a single virtual reservoir, it is difficult to analyze the surplus or shortage of agricultural water for each field within the basin. There are limitations in reflecting the characteristics and actual sites of rural water areas, such as inconsistencies with river and reservoir supply priority sites. This study focuses on the development of a model aimed at improving the deficiencies of current water balance analysis methods. The developed model aims to provide standardized water balance analysis nationwide, with initial application to the Anseo standard watershed. Utilizing data from 32 facilities within the standard watershed, the study conducted water balance analysis through watershed linkage, highlighting differences and improvements compared to existing methods.

• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.332-339
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• 2012

Objectives: The purpose of this study was to prevent health problems and environmental contamination resulting from inappropriate management of dental wastes and to provide reference data for revision and supplementation of dental clinic waste management guidelines. Methods: From 640 total of dental clinics registered in 16 cities and counties in Gyeongsangnam-do, 100 (60 in Changwon (Masan, Changwon), 29 in Gimhae, and 11 in Jinju) were included in this study. From July 2010 to September 2010, investigators visited the 100 dental clinics and conducted survey interviews using a structured survey questionnaire regarding disposal methods for liquid wastes (suction pump, spittoon container waste, used liquid disinfectants, and X-ray developer), and disposal methods for solid waste (suction pump, spittoon container waste, and general medical waste). Results: All the 100 dental clinics were found to treat liquid waste from suction pumps and spittoon containers in the same manner as general waste water. Nineteen percent of the clinics treated solid waste that was not filtered through the filter of a suction pump as general waste. Fifty or more percent of the clinics treated solid waste in spittoon containers as general waste. Seventy percent of the clinics used disinfectant solution, although most of them treated used disinfectants in the same manner as general waste water. Some clinics treated used X-ray developer and X-ray fixer in the same manner as general waste water. In most of the clinics, used drapes were washed within the clinic. Conclusions: It was found that waste water and dental wastes at some dental clinics were treated in inappropriately. Thus, in conclusion, the development of guidelines regarding proper management of liquid and solid dental waste at dental clinics is required, and hygiene and environmental training for workers at dental clinics is necessary.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.4
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• pp.85-98
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• 2003

There has recently been an increasing interest of the watershed management as a solution to a wide range of problems related water environment, therefore this study attempted to construct the environment information system to monitor the Geumho River watershed, and to evaluate the impacts of the watershed characteristics on stream water quality. A detailed GIS database to analyze the environmental characteristics at the subwatershed units, including 1:25,000 scale topographical maps, detailed soil maps, land use, 10m-resolution DEMs, roads, streams, vegetation index(NDVI) calculated from Landsat TM imagery, rainfall, and soil loss using RUSLE, is compiled for the study area. The set of variables representing watershed urbanization or industrialization, residential and commercial landuse, industrial landuse, and road area have significantly negative(-) relationship with water quality variables(BOD, COD, SS, T-N, T-P). On the other hand, watershed indicators related to natural environmental conditions, forest cover and vegetation index(NDVI) in each subwatershed were significantly positive(+) relationship with water quality. Three other variables, agricultural landuse, amount of fertilizer and pesticides, and potential soil loss, were not significant in explaining the correlations between watershed environment and stream water quality.