• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.495-504
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• 2012

In recent years, urbanization has been a hot issues in watershed management due to increased pollutant loads from impervious urban areas. The Soil and Water Assessment Tool (SWAT) model has been widely used in hydrology and water quality studies at watershed scale. However, the SWAT has limitations in simulating water flows between HRUs and hydrological effects of LID practices. The Storm Water Management Model (SWMM) has LID capabilities, but it does not simulate non-urban areas, especially agricultural areas. In this study, a SWAT-SWMM coupled model was developed to evaluate effects of LID practices on hydrology and water quality at mixed-landuse watersheds. This coupled SWAT-SWMM was evaluated by comparing calibrated flow with and without coupled SWAT-SWMM. As a result of this study, the $R^2$ and NSE values with SWAT are 0.951 and 0.937 for calibration period, and 0.882 and 0.875 for validation period, respectively. the $R^2$ and NSE values with SWAT-SWMM are 0.877 and 0.880 for validation period. Out of four LID scenarios simulated by SWAT-SWMM model, the green roof scenario was found to be most effective which reduces about 25% of rainfall-runoff flows.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.63-72
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• 2017

For economic evaluation of integrated operation to sewage facilities, benefit-cost analysis was performed to watershed sewage works project in 7 watershed areas, 156 facilities. In this study, the cost before and after integrated operation was compared and benefits are calculated from the reduction of operators, increasement treated pollution loads, reduction cost through operation convenience, reduction water consumption through effluent reuse, and improvement of life benefit. The result showed that cost was 8,500million won and benefit was 16,747million won, so benefit was 49% higher than cost. B/C analysis result showed that B/C ratio was 1.97 and it is similar to other researches. The benefits of integrated operation included convenience of data management, increase of emergency response, decrease of complains with sewage which was not reflected numerically, so the benefits of integrated operation were expected much greater than this result

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1239-1243
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• 2005

The water quality of the Ian Stream, a tributary of the Na14dong River, was estimated to provide an information in establishment of an ecological restoration plan for fan dam which will be constructed in near future. Seven stations were selected in upstream (3 stations) and downstream (4 stations) of Ian Stream, centering the construction site of Ian dam. Samples were collected at the surface water of 7 stations selected on May 1, June 16, and September 1 in 2004. The values of DO, pH, and BOD are satisfied Grade I for river water standard in nearly all sites. The concentrations of total nitrogen (TN) and total Phosphorus (TP) showed low level with ranges of $1.10\~2.25\;mgN/L,\;5\~14\;{\mu}gP/L$. However, the total and fecal conform bacteria were detected in nearly stations, especially high at the upstream stations. The number of fecal conform bacteria corresponds to the Grade III for river water standard. In addition, some metals (iron, manganese) were detected during dry season. As a consequence, general water quality of Ian Stream satisfied Grade I for river standard and it is expected that pollution loads from watershed is not significant. However, the detection of fecal conform, which is thought to be from livestock and residents, and some metals originating mimes watershed can have a potential health risk exists for aquatic organisms lived in Ian Stream. It needs to be solved by the construction of wastewater treatment plant to diminish the health risk from stream water polluted by fecal conform and metals, and to provide the safe ecological habitat for aquatic organisms.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2117-2121
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• 2009

우리나라는 도시화, 산업화로 하천의 환경적인 기능을 고려하지 못하고 심각한 수질오염을 유발하여 왔다. 특히 기술개발로 점오염원에 관리는 어느정도 효과를 보고있으나 정량화가 힘든 비점오염원 관리는 제대로 이루어지고 있지 않다. 우리나라의 강우시 수자원관리를 위한 기초자료로서 활용하기 위하여 본 연구에서는 강우시 수질특성을 파악하고자 하였다. 비점오염원의 특성상 유역별, 강우사상별 특징이 매우 다르므로 대표 유역에 대하여 장기적인 모니터링을 통하여 대표유역의 특성을 반영한 제한적인 누가유량-누가오염부하량의 관계식을 도출하여 좀더 정밀한 유역오염부하량을 산정하는 데 기여하고자 하였다. 연구 지점은 수도권 및 인근지역 주민의 식수원인 팔당호로 직 유입되고 정확한 유량자료 확보가 가능한 경안수위관측소 지점으로 선정하였다. 연구기간은 2007년 6월$^{\sim}$2008년 12월이었으며 이 기간에 나타난 강우 중 4개의 강우사상에 대하여 수질측정 및 실시간 수위관측을 실시하였다. 수위-유량관계곡선식으로 산정한 유량자료와 실측한 수질자료를 바탕으로 누가유량-누가오염부하량의 단순회귀식을 도출하였다. 수질항목은 수온, DO, pH, EC, SS, BOD, $COD_{Mn}$, $COD_{Cr}$, T-N, T-P 등이며 단, BOD는 2개의 강우사상에서만 측정되었다. 현장에서 휴대용미터를 이용하여 수온, DO, pH, EC를 측정하였고 나머지 항목은 한국건설 기술연구원내 환경정밀분석센타에 의뢰하여 분석하였다. 각 항목별 실측치를 이용한 누가유량-누가오염부하량 관계식을 도출한 결과 각 도출된 식의 상관계수 값은 전 항목에서 0.9 이상으로 1에 가깝게 나타나 높은 상관관계을 가지는 것으로 분석되었다. 항목별로 보면 BOD는 0.95, SS는 0.96, $COD_{Mn}$은 0.98, $COD_{Cr}$은 0.95, T-N은 0.97, T-P는 0.92의 값을 가졌다. 앞으로 장기적인 모니터링이 지속적으로 이루어져 다양한 강우사상별 자료가 축적된다면 좀더 정밀한 유량-부하량 관계식을 도출할 수 있을 것으로 판단되며 이는 수자원관리에 중요한 자료가 될 것으로 기대된다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.825-835
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• 1994

The distributions of temperature, salinity, dissolved oxygen, chemical oxygen demand, dissolved inorganic nitrogen and phosphate in the Yellow Sea are described from data collected in June and July, 1994. Based on the observations of water temperature and salinity, the fresh waters originated from the Changjiang River were found to affect the waters adjacent to Cheju Island. In the light of the distributions of dissolved oxygen and chemical oxygen demand, the western part of the Yellow Sea was worse in water quality than the eastern part. Based on data of nutrients, eutrophication indices of the western part were higher than those of the eastern part in summer. It is concluded that the western part of the Yellow Sea appeared to receive high pollution loads from rivers and was evaluated to have high potentiality of red tide occurrence.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.2
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• pp.126-132
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• 2012

In recent years, serious environmental problems occur in coastal area due to high pollution loads from human activity in land. Marine biomass utilization system therefore has been proposed to prompt material circulation between land and sea. Comprehensive assessment is necessary to determine that the proposed system is suitable and sustainable. This study introduces thermodynamic concept exergy, which expresses energy quality, to describe material and energy flowing in the material circulation system. This study presents material, energy and exergy flows in the material circulation system at Sakai city located in the middle of Osaka in Japan. It is found that exergy helps a better understanding of what is a key role is in exergy-efficient material circulation system.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.792-802
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• 2009

The objective of this study is to construct the watershed management system with link of the non-point sources model and to estimate delivery ratio duration curves for various pollutants. For the total water pollution load management system, non-point source model should be performed with the study of the characteristic about non-point sources and loadings of non-point source and the allotment of pollutant in each area. In this study, daily flow rates and delivered pollutant loads of Nakdong river basin are simulated with modified TANK model and minimum variance unbiased estimator and SWAT model. Based on the simulation results, flow duration curves, load duration curves, and delivery ratio duration curves have been established. Then GIS analysis is performed to obtain several hydrological geomorphic characteristics such as watershed area, stream length, watershed slope and runoff curve number. As a result, the SWAT simulation results show good agreements in terms of discharge, BOD, TN, TP but for more exact simulation should be kept studying about variables and parameters which are needed for simulation. And as a result of the characteristic discharges, pollutants loading with the runoff and delivery ratios, non-point sources effects were higher than point sources effects in the small-scale test bed of Nakdong river basin.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.2
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• pp.235-242
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• 2007

Road runoff water includes various heavy metals (zinc, Zn; lead, Pb; copper, Cu; chrome, Cr; cadmium, Cd; etc.) and pathogens (E-coli and coliform). Since these pollutants are significantly harmful to human beings and have negative impact on water streams, numerous studies have been conducted to determine the characterization of these non-point pollutants from road runoff water. However, since these non-point pollutant concentrations vary depending on road traffic, road construction, and road maintenance, measurement of pollutant loadings in different site is necessary to estimate the effect of road runoff water on drinking water source. The objective of this study was to examine the quality of road runoff water from a city bridge in Seoul, Korea. This study was conducted for two years to assess annual discharge pollution loads. In this study, five key heavy metals (Zn, Pb, Cu, Cr, and Cd) and two pathogens (E-coli and coliform) were measured at 18 different events. The pollutant load mass transported was always higher than the corresponding runoff volume for Zn, Cu, and Cd, while Pb and Cr showed similar values between the load mass transported and the corresponding runoff volume. The event mean concentrations were Zn (0.908 mg/L), Pb (0.092 mg/L), Cu (0.141 mg/L), Cr (0.023 mg/L), and Cd (0.006 mg/L). Like Zn, Cu, and Cd, E-coli and coliform values (relatively high in Summer and Fall) are higher at the beginning of each event and decrease afterwards.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.885-892
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• 2011

In this study, LCA(Life Cycle Assessment) on 'Saemangum CSO Project' was carried out to evaluate environmental impact which occurred during the construction and operation periods and the potential environmental impact reduction was analyzed by comparing production and reduction level of pollution loads. LCA was conducted out according to the procedure of ISO14040 which suggested Goal and Scope Definition, Life Cycle Inventory Analysis, Life Cycle Impact Assessment and Interpretation. In the Goal and Scope Definition, the functional unit was 1 m3 of CSO, the system boundary was construction and operation phases, and the operation period was 20 years. For the data collection and inventory analysis, input energies and materials from civil, architecture, mechanical and electric fields are collected from design sheet but the landscape architecture field is excepted. LCIA(Life Cycle Impact Assessment) was performed following the procedure of Eco-Labelling Type III under 6 categories which were resource depletion, eutrophication, global warming, ozone-layer destruction, and photochemical oxide formation. In the result of LCA, 83.4% of environmental impact occurred in the construction phase and 16.6% in the operation phase. Especially 78% of environmental impact occurred in civil works. The Global warming category showed the highest contribution level in the environmental impact categories. For the analysis on potential environmental impact reduction, the reduction and increased of environmental impact which occurred on construction and operation phases were compared. In the case of considering only the operation phase, the result of the comparison showed that 78% of environmental impact is reduced. On the other hand, when considering both the construction and operation phases, 50% of environmental impact is increase. Therefore, this study showed that eco-friendly material and construction method should be used for reduction of environmental impact during life cycle, and it is strongly necessary to develop technology and skills to reduce environmental impact such as renewable energies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.605-612
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• 2017

One of the biggest environmental issues that our world has been facing is climate change. In order to cope with such environmental issues, the world is putting a great deal of effort into energy conservation. The building sector, in particular, consumes 36% of the energy consumed worldwide and emits considerable amount of greenhouse gases. Therefore, introduction of renewable energies in the building sector is highly recommended. Renewable energy sources that can be utilized in the building sector include sunlight, solar heat, geothermal heat, fuel cells and wind power. The wind power generation system which converts wind energy into electrical energy has advantages in that wind is an unlimited and pollution-free resource. It is suitable to be connected to existing buildings because many years of operational experience and the enhanced stability of the system have made it possible to downsize the electrical generator. In case of existing buildings, it is necessary to consider the live loads of the buildings to connect the wind power generation system. This paper, through the connection of the wind power generation with existing buildings, promotes reduction of greenhouse gas emissions and energy independence by reducing energy consumption in the building sector. In order to connect the wind power generation system with an exciting building, the live load of the building and the area of the rooftop should be considered. The installable model is selected by comparing the live load of the building and the load of the wind power generation system. The maximum number of the wind turbines that can be installed is obtained by considering the separation distance between the wind turbines within the area of the rooftop. Installations are divided into single installations and multiple installations of two different types of wind turbines. After determining the maximum installable number, the optimal model that can achieve the maximum annual power generation will be selected by comparing the respective total annual amount of the power generation of different models.