• Journal of Korean Society on Water Environment
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• v.34 no.5
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• pp.487-493
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• 2018

Urban stormwater runoff is the one of the most extensive causes of deterioration of water quality in streams in urban areas. Especially, in the Suyeong River watershed, non-point sources from urban-residential areas are the most common cause of water pollution. Also, it has been ascertained that BOD and COD as indexes of organic matter, have limitation on management of Suyeong River's water quality. In this study, changes of organic matter properties of Suyeong River from inflow of non-point source during rainfall were investigated. Fractions of organic matters were analyzed using water samples collected at two sites (Suyeong River and Oncheon Stream) during a rain event. Variations of dissolved organic carbon (DOC) concentration by rainfall were similar to flow rate change in the river. Distribution of organic matter fraction according to change of rain duration revealed that while hydrophilic component increased at initial rainfall, the hydrophobic component was similar to change in dissolved organic carbon (DOC) concentration. Also, the relative proportion of hydrophilic components in organic matter in river water increased, due to rainfall. Results of biodegradation of organic matters revealed that decomposition rate of organic matters during rainfall was higher than that of during a non-rainfall event.

• Journal of The Geomorphological Association of Korea
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• v.28 no.4
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• pp.1-13
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• 2021

In this study is aerial photos and UAV(Unmanned Aerial Vehicle) images were used to analyzed the characteristics of depositional landform changes in the Geum river channels before and after the opening gate of Gongju weir. Based on the depositional landform classification result, the main stream and the bare land occupied most of the area in all periods, and also found that the main stream, mid-channel island, and sand bar occupied a greater degree of area increase or decrease compared to other landforms in the classification items. As a result of analyzing the characteristics of depositional landform changes before and after the opening gate of Gongju weir, it is judged that the depositional landforms have changed due to the decreased water level of the Geum river after the opening of the weir, the summer rainy season and typhoons, river stabilization after the effluence of Daecheong dam, supply and deposition of river sediments and fixation of vegetation. The results derived from this study can be used as basic data for the study of river depositional landforms and the establishment of management and conservation plans for the landforms in river channels.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4B
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• pp.213-220
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• 2012

Old river channels have been formed by engineering a straight channel in Korea. This can be classified as wetland-type or land-type. The wetland-type old river channel uses parts of agricultural water supply. However, the channels have been neglected since there are problems associated with poor water quality, reduced water level, ecosystem disturbance, etc. Thus, river maintenance through preservation and restoration of old river channel can be very effective in watershed management. To achieve this, functional assessment of wetland-type old river channel is a priority need. This study applied the wetland-type channel in Mangyoung river for functional assessment. It was formed these channels with regard to the following four major criteria (Natureless, Habitat, Water-friendliness and Water quality) and 21 indices. The indices managed by measuring depending in weights. Consequently, wetland-type channel in Mangyoung river was in good condition both natureless and habitat, while it was a fragile environment in water-friendliness and water quality. In particular, the areas where it has insufficiency water and water suffering from eutrophication needs urgent improvement. This results will be used to utilize wetland-type old river channel as watershed management.

• Journal of Environmental Impact Assessment
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• v.26 no.1
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• pp.57-67
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• 2017

Recently, Looking at the watershed management policy in Korea, It is preparing to manage sub-watershed and tributary from the government-led mainstream management, such as the selection of algae focused management tributary, application of tributary-TMDLs. At this point, this study is attempted to propose the residents participatory watershed management methods that is possible daily, voluntary and customized management in the sub-watershed. As a results, through this study, we found out the importance of sub-watershed unit based watershed management because of the pollutants in blind spot. It is the prerequisite for watershed management to arrange practicable bottom-up approach that these investigated contents can be reflected in the various planning.

• Journal of the Korean Professional Engineers Association
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• v.35 no.4
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• pp.48-51
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• 2002

Due to locally torrential downpours which shows Increasing trend, high tide of the southern sea of Korea and etc. submerged and Inundated districts at the lowlands of Nakdong River Basins has been Increasing year by year In order to protect flood hit, it is necessary to make an early implementation of flood control dam and other flood protection works according to Nakdong River Comprehensive Development Project. In addition to the large scale comprehensive projects, local key measures, such as lowland development control, embankment reinforcement, leakage protection, maintenance and management of facilities, increase in pumping station, will be highly effective.

• Journal of Environmental Science International
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• v.11 no.10
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• pp.1125-1131
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• 2002

This study was performed to plan pollutant loading allocation by sub-watershed at Kumho river basin located in the north Kyeongsang province. HEC-geoHMS which is extension program of ArcView was used to extract sub-watershed. To simulate water quality, Qua12eu model was calibrated and validated. BOD was simulated under several scenarios to evaluate reduction effects of pollutant loading. Uniform treatment and transfer matrix method was considered. Effects of headwater flow rate and efficiency waste water treatment plant were also considered.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.4
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• pp.417-428
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• 2020

The characteristics of the construction project involved various stakeholders' involvement from the planning stage until completion of the object, which caused the uncertainty to increase. Successful construction projects require risk analysis and appropriate responses. Therefore, this study aimed to confirm the influence of risk management factors on the success of river disaster prevention construction in construction projects and the effect of moderating communication between stakeholders involved in the construction process. The Delphi method was used to derive the risk management factors of the construction process. The survey used a snow ball sampling method. For analysis, SPSS Statistic 20 and SmartPLS 2.0 were used. As a result of the study, the impact of risk management factors on project performance was found to be large in the order of time risk, quality risk, cost risk, safety risk, and construction environment risk. In addition, the impact of the communication moderating effect was large in the order of cost risk, quality risk, construction environment risk, time risk, and safety risk. In this study, it was confirmed that communication between stakeholders related to river disaster prevention work has a moderating effect that changes the ranking of impacts on project performance. This shows the importance of communication in the construction process of river disaster prevention works. This study has important significance in that it identifies the importance of risk management factors and communication in river disaster prevention works.

• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.34-38
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• 2009

Based on the design of the LIS of GuangZhou and BeiJing, this paper discusses the resolution of the LIS with the kernel of process management. It applies the idea of workflow in the management supporting stratum, applies the process-oriented mechanism in the definition, coordination, supervision and control of the management process. The scheme has the character of information-media-oriented, work process dynamic changing supported, application system extended and restructure supported and is independent of the running environment of specific work.. Due to the previous character, the LIS is flexible, useable, elastic and able to support the dynamic application.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.39-46
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• 2016

In this paper, the relationship between energy consumption in the logistics industry and economic growth of Tumen River region from 1995 to 2014 is empirically analyzed by using the EKC model theory. The results show that there is a turning point in the Kuznets curve of carbon emission in TumenRiverregion. And it has the characteristic sof "invertedU" curve, which conforms to the environmental Kuznets curve hypothesis. Meanwhile it is stil lintherisingstage. According to the analysis results, it is proposed to set up the concept of low carbon logistics, optimize the energy structure, strengthen the information construction, and establish low-carbon development mechanism and so on.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.185-185
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• 2011

Mapping of artificial levee lines, one of major tasks in river zone mapping, is critical to prevention of river flood, protection of environments and eco systems in river zones. Thus, mapping of artificial levee lines is essential for management and development of river zones. Coastal mapping including river zone mapping has been historically carried out using surveying technologies. Photogrammetry, one of the surveying technologies, is recently used technology for national river zone mapping in Korea. Airborne laser scanning has been used in most advanced countries for coastal mapping due to its ability to penetrate shallow water and its high vertical accuracy. Due to these advantages, use of LiDAR data in coastal mapping is efficient for monitoring and predicting significant topographic change in river zones. This paper introduces a method for construction of a 3D artificial levee line using a set of LiDAR points that uses normal vectors. Multiple steps are involved in this method. First, a 2.5-dimensional Delaunay triangle mesh is generated based on three nearest-neighbor points in the LiDAR data. Second, a median filtering is applied to minimize noise. Third, edge selection algorithms are applied to extract break edges from a Delaunay triangle mesh using two normal vectors. In this research, two methods for edge selection algorithms using hypothesis testing are used to extract break edges. Fourth, intersection edges which are extracted using both methods at the same range are selected as the intersection edge group. Fifth, among intersection edge group, some linear feature edges which are not suitable to compose a levee line are removed as much as possible considering vertical distance, slope and connectivity of an edge. Sixth, with all line segments which are suitable to constitute a levee line, one river levee line segment is connected to another river levee line segment with the end points of both river levee line segments located nearest horizontally and vertically to each other. After linkage of all the river levee line segments, the initial river levee line is generated. Since the initial river levee line consists of the LiDAR points, the pattern of the initial river levee line is being zigzag along the river levee. Thus, for the last step, a algorithm for smoothing the initial river levee line is applied to fit the initial river levee line into the reference line, and the final 3D river levee line is constructed. After the algorithm is completed, the proposed algorithm is applied to construct the 3D river levee line in Zng-San levee nearby Ham-Ahn Bo in Nak-Dong river. Statistical results show that the constructed river levee line generated using a proposed method has high accuracy in comparison to the ground truth. This paper shows that use of LiDAR data for construction of the 3D river levee line for river zone mapping is useful and efficient; and, as a result, it can be replaced with ground surveying method for construction of the 3D river levee line.