• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.682-688
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• 2009

A plane field and a sloped field located at low-land plane and alpine areas, respectively, were monitored with respect to runoff, water quality and fertilizer uses from March to December, 2008. Runoff volume and Non-Point Source (NPS) loads were estimated and analyzed with respect to fertilizer uses. Total TN and TP loads from the sloped field were higher than those from plane field because of larger chemical uses in the alpine field than in the plane field. Organic matter load from plane field was higher than that from sloped field because more organic compost was applied to plane field than to sloped field. Event Mean Concentration (EMC) of measured water quality indices were relatively higher in both fields. Organic matter load per 1 mm rainfall were higher in plane field and TN and TP loads per 1 mm rainfall were higher in sloped field than those in respective comparing field. It was concluded that the type and application method of fertilizer could play an important role in the estimation of NPS pollution loads and the development of Best Management Practices (BMPs). However, it was recommended that long-term monitoring is necessary to better describe the relationship between fertilizer uses and water quality from agricultural fields because numerous natural and management factors other than fertilizer also affect runoff quality.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.617-625
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• 2017

Both domestic and overseas urban drainage systems have been actively researched to solve the problems of urban flash floods and the flood damage that is caused by local downpours. Recent urban planning has been designed to better manage the floods of decentralized rainfall-management systems, and the installation of green infrastructure and low-impact development (LID) facilities at national ministries has been recommended. In this study, we use the EPA SWMM model to construct a decentralized rainfall-management network for each small watershed, and we analyze the effect of the drainage-capacity improvement from the installation of the LID technologies in vulnerable areas that replaces the network-expansion process. In the design of the existing urban piping systems, it is common to increase the pipe size due to the increment of the impervious area, the steep terrain, and the sensitive entrance-ramp junction; however, the installation of green infrastructure and LID facilities will be sufficient for the construction of a safe urban drainage system. The applications of LID facilities and green infrastructure in urban areas can positively affect the recovery of the corresponding water cycles to a healthy standard, and it is expected that further research will occur in the future.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.569-580
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• 2008

In this study, area-weighted slope and slope length module, considering measured field slope and slope length of the agricultural fields within the subwatershed, was developed using the ArcView Avenue programming to reflect the field topography of the Soil and Water Assessment Tool (SWAT) HRU in simulating the hydrology and water quality. Flow and sediment yield estimated values of the SWAT were compared with and without applying area-weighted slope and slope length module, developed in this study. There was 103% increases in estimated sediment with area-weighted slope and slope length module for the study watershed. The soil erosion and sediment yield from only agricultural field in Hae-an watershed was also assessed. There are 111% increase in estimated soil erosion and 112% increase in estimated sediment by applying area-weighted slope and slope length module. This study shows that the area-weighted slope and slope length module needs to be utilized in estimating the HRU field slope and slope length for accurate estimation of soil erosion and nonponit source pollutant modeling with the SWAT although it is not feasible to measure topographic information for every agricultural fields within the watershed. The area-weighted slope and slope length module can be used in identifying soil erosion hot spot areas for developing cost effective and efficient soil erosion management practices.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.4
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• pp.33-42
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• 2019

In this study, the channel and floodplain widths are indirectly measured for three different watersheds using satellite images to reflect the shape of Korean channels in the Soil and Water Assessment Tool (SWAT) model. For measuring the channel and floodplain widths, multiple satellite images were referred to ensure the widest width of certain points. In the single channel, the widths at the multiple points were measured. Based on the measured data, the regression equations were derived to estimate the channel and floodplain widths according to watershed areas. Applying these developed equations, this study evaluated the effect of the change of channel and floodplain widths on the SWAT simulation by comparing to the measured streamflow data. The developed equations estimated larger channel width and smaller floodplain compared with those calculated in the current SWAT model. As shown in the results, there was no considerable changes in the predicted streamflow using the current and developed equations. However, the flow velocity and channel depth calculated from the developed equations were smaller than those of the current equations. The differences were caused by the effect of different channel geometries used for calculating the hydraulic characteristics. The channel geometries also affected the water quality simulation in channels because the hydraulic characteristics calculated by the channel geometries are directly related to the water quality simulation. Therefore, application of the river cross-sectional regression equation reflecting the domestic stream shape is necessary for accurate water quantity / quality and water ecosystem simulation using hydrological model.

• Water for future
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• v.43 no.5
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• pp.100-105
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• 2010

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.602-603
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.82-90
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• 2010

New Zealand appears to be a water rich country; however there are considerable water allocation issues. Mostly these revolve around balancing environmental concerns with economic development. The largest economic sector is agriculture which currently utilizes around 80% of the allocated water and has considerable potential to increase in size. The resource management framework that New Zealand has developed over the past twenty years revolves around local decision-making and sustainable management principles. As the demands for water have grown there has been growing concern that this framework is inadequate to deal with the issues of declining water quantity and quality through agricultural intensification. In Canterbury, the region with the highest water allocation and demand, a new approach is being trialed. The Canterbury Water Management Strategy (CWMS) recognizes the need for: ecological restoration for past damage; infrastructure development for increased irrigation; and the need to link infrastructure with more efficient use of water by both existing and new water users. These three elements are recognized as having equal value. The CWMS builds on the local decision-making concept but is deliberately aimed at consensus building in order to remove expensive and adversarial resource management hearings. It is practical enough to recognize that economic development is needed but that it need not proceed in conflict with the environment, but rather can be a means towards environmental improvement.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.27-35
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• 2022

Based on the current status of groundwater usage in the dry season through field surveys, this study tried to suggest countermeasures to reduce groundwater usage and to improve the water quality of baseflow from agricultural fields. For this purposes, basins with water curtain cultivation preceded were targeted where decreases of groundwater due to continuous use of groundwater in spring and winter annually observed. From monitoring groudwater usage of the study watershed, 130,058, 130,105 m³/day of water was pumped in during the water curtain cultivation period (October-February) in the Shindun, Seokwon watershed respectively. And the pilot application of the smart automated sensor-based water curtain cultivation system (smart WC system) developed in this study to reduce groundwater consumption has been conducted. As a result, the efficiency of the smart WC system when threshold temperature is set as 6.3 ℃ was 21.1% compared to conventional cultivation and efficiency increased as threshold temperature gets lower. Lastly, in this study, culvert drainage and Bio-filters were installed and rainfall monitoring was performed 15 times in order to analyze the baseflow securement and pollutant loads behavior. As a result, the test-bed with culvert drainage and Bio-filter installed together generated 61.4% more baseflow (4.974 m³) than the test-bed with only culvert drainage was installed (3.056 m³). However, the total pollutant load of all water quality contents (BOD, COD, T-N, TOC) except for the SS and T-P was found to be greater in the culvert drain and Bio-filter installed than in the culvert drain test-bed.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.83-90
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• 2022

Public-private partnerships (PPP) projects are becoming popular in both developed and developing countries due to their ability to access new financing sources and transfer certain project risks to the private sector. PPP has been an active research area where the concept of Critical Success Factors (CSF) is often discussed by researchers. This study aims to identify the CSFs for various PPP infrastructure projects that have been explored in previous CSF studies. This article reviewed the literature about CSF in PPP projects from the years 2002 to 2021, compared the findings of studies regarding the identified CSFs, and consolidated the CSFs that can be applied to various PPP infrastructure projects. The results showed that dominant research focused on general infrastructure, where CSFs can be applied to all infrastructure sectors rather than any specific sector. The most identified CSFs from the study are favorable and efficient legal frameworks, appropriate risk allocation and sharing, a robust and reliable private consortium, a competitive and transparent procurement process, and political support and stability. The findings from the study can provide an overview of CSFs that are relevant to specific PPP infrastructure sectors like building infrastructure, transportation, water, etc. as well as for general infrastructure. In addition, the results can also be used for further empirical analysis.

• Journal of environmental and Sanitary engineering
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• v.24 no.1
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• pp.1-12
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• 2009

The various environmental problems that we face on today are basically about environmental quality. Since early 1960s affluent material was produced because of remarkable economic growth by many cooperations. However, for the lack of environmental policy, environmental pollutions has been serious. The central government should transfer the producing and consuming structure to environmental affinity through the regulations for developing Korea as a model of environmental nation which takes an active part in global environmental programme and in which the environment and economy are well harmonized. Moreover, the central government should take the lead in prevention of environmental pollution through the direct policies such as strengthening the discharge limit or setting up environmental basic institutions by securing budget for conserving environment. This thesis emphasize on the public institution among many environmental basic institutions for environmental anti-pollution project. It will find the problems with running those institutions, and will suggest the preview of improvement. Also, it is necessary to investigate of variation trend for inflow and pollutant loading to environmental infrastructure as increased of the diffusion rate as established and maintenance of sewer system. The purpose of this study is to investigate for inflow and pollutant loading to environmental infrastructure, and also to provide the method of efficiently maintenance and management. The results obtained were summarized as follows; 1. Survey of actual condition on operation and management of environmental infrastructure was evaluated the propriety of treatment process and problem of plant management. 2. Analysis of pollutant loading contribution for river system of environmental infrastructure with data analysis of water quality measuring network. 3. To investigate on case study for efficiently maintenance and management of environmental infrastructure. The result on this study was provide the method of efficiently maintenance and management with survey for establish and repair of sewer system and survey of actual condition on operation and management of environmental infrastructure in the water area of discharge to Geum River System. Application as guideline for establish and management of environmental infrastructure, and management of Geum River System. Also, application for preliminary data for fulfill-assess of total effluent regulation of water pollution.