• Journal of Korea Water Resources Association
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• v.45 no.5
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• pp.465-472
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• 2012

Recently, as the development of water front and natural type river is gradually increasing, it is mostly the case in that the flow analysis is implemented by only the flood level of the starting point without the tidal effect when the flood water level of the starting point is highly estimated than the high tidal water level in the design of river adjacent to an estuary. This research has analyzed the variation of tidal current for Oncheon river in Busan using Delft-3D program, considering that the tidal effect can cause the change of the flood water level of the starting point although the flood water level is higher than the flood tide level. As a result, considering the tidal effect at downstream boundary condition, water level indicates a periodicity of tide in particular region and the fluctuation range of water level is extended to upstream.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.40-49
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• 1997

From water management point of view, the industrialization that we have achieved in the last decades brought out two major changes: water shortage and water quality deterioration. They are getting the big obstacles we must overcome to continuously pursue industrialization for further development in the next century. Many plans using dams and advanced treatment methods have been developed for control of quantity and quality, respectively. In this paper, an alternative is conceptually reviewed which is much different from the plans in regard that the alternative looks at system itself. It is based on an interceptor system coupling with a concept of zero-discharge. This system allows no discharge of wastewaters from point-sources to waterbodies which are very sensitive in terms of water quality. In addition reuse of treated effluents is emphasized to a maximum extent. The application of the system to the Nak-Dong river basin indicated that an interceptor system will need from the middle reaches of the basin where industrialization gets heavier. Since wastewaters are not directly discharged to the river, water quality of the down stream will improve. Treated effluents will be able to be reused at a number of industrial complex which currently get water from the Nak-Dong river. This reuse will help alleviate water shortage. The biggest problem anticipated is cost for building and operating such system. A cost-sharing plan among the beneficiaries is considered. Further research is suggested focusing on detailed engineering and technical matters for potential implementation.

• Journal of the Korean Geotechnical Society
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• v.25 no.11
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• pp.5-15
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• 2009

Dynamic shear properties of Nak-Dong river sand were investigated to build a soil property database for Nak-Dong delta region. Samples were taken from the estuary and the midstream of the river. Laboratory specimens were prepared by air pluviation method, and were tested by using RC/TS apparatus at various confining stresses, relative densities and numbers of cycles. Shear modulus reduction and damping curves were developed using Ramberg-Osgood and Modified Hyperbolic Models. The developed curves, compared to those reported by other investigators, show only a slight difference. The outcome of this RC/TS experiments can be very important resources when accessing the dynamic response of sandy soils in Nak-Dong delta region in the future.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.69-74
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• 2016

Bathymetric changes were studied in the southern sea off the Jinwoo-do Island, which is one of the deltaic barrier islands surrounding the Nakddong river estuary. In this study, 16 bathymetry data sets were obtained from June 2006 to April 2015. Two narrow channels, the one lying between Jinwoo-do and Shinja-do, and the other one lying between Nulcha-do and Jinwoo-do extended into the eastern and western parts of the study area, respectively. The eastern extension of the channel contained a passage of mixed estuarine waters of seawater and river water discharged from the Nakdong river barrier and the west Nakdong River. The western channel connected the Nakdong River estuary with the Busan New Port via a connecting pier. Total volumetric changes of sediments in study area and discharge flow of the Nakdong river barrier were analyzed. Bottom topographical changes occurred mainly in the eastern extension of the channel. These changes were initially characterized by gradual erosion or deposition followed by rapid restoration. The total volume of sediment gradually increased from June 2006 to March 2013, but experienced a sudden decrease in October 2013 because of typhoon Danas. Few fluctuations were observed from October 2013 to April 2015. Analysis of the cross-sectional bathymetry of the north-south direction showed that the deepest point of the eastern channel moved 100-130 m westward and 200 m northward between June 2006 and April 2015.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1732-1736
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• 2008

The characteristics of a river flow analysis are significant for river maintenance plan. At the present time, HEC-RAS, 1-Dimensional Numerical Analysis Model, is mainly applied to analyze the character of a river flow. The shape of a river is somewhat in longitudinal linear form. It was suspected that the usage of 1-dimensional numerical analysis model is more economical. Development of numerical analysis models and computers are possible to calculate large volume. Hence, it is possible to adapt the analysis of the key stations by 2-dimensional numerical analysis model. The limitation of 1-Dimensional Numerical Analysis Model is that it is hard to evaluate structure affection of numerical simulation by energy loss coefficient at river structure analyzing. When adaptation of the 2-dimensional numerical analysis model in river structure ensues, it takes more objective analyzing than 1-dimensional numerical analysis model for flow affection by river structure. 2-dimensional numerical analysis model consults with the different structure position of hydraulic characteristics and different water depth of shape and scope in vertical flow. 1-dimensional numerical analysis model is possible to simulate with only energy loss coefficient for sudden river section changing, sudden waterway changing by curved. 2-dimensional numerical analysis model use original geographical features. So the model removes technical subjectivity of faulty judgment. It is an objective analysis.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.297-316
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• 1996

This research emphasizes the necessity of the understanding and cooperation among focal governments to preserve the water quality of the Nak-dong river that runs through four local governments. First, this research considers the status of water-pollution in the Nakdong river, describes and finds problems within the central government's. "Clean Water Supply Plan" and local governments' water quality-related policies. Second, it deals with the conflict among local governments concerning the planning and building of "Wicheon Industrial Complex" in the middle-upstream of the Nakdong river which has triggered the opposition movement of the local governments and residents of the river's downstream area. With stressing the necessity of the understanding and cooperation among local governments, this research emphasizes roles of central government, of academic experts, and of local news-media in preserving the water quality. Key words : the Nakdong river, water quality policy, the conflict among local governments, the activation of local autonomy, Wicheon Industrial Complex, the cooperation among local governments.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.4
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• pp.1-7
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• 2019

Cooling using the Han River has recently been spreading. The Ministry of Trade, Industry and Energy submitted a revised enforcement ordinance to include river water in renewable energy. Therefore, it is necessary to analyze the water temperature characteristics of Han River. Especially, it is necessary to investigate the effect on hot summer. In this study, we analyzed the water temperature of the last 11 years. It is intended to utilize the Han River for building cooling in the future.

• Journal of Environmental Science International
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• v.21 no.9
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• pp.1131-1138
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• 2012

The aims of this study were to investigate and confirm the occurrence and distribution patterns of iodinated X-ray contrast media (iopromide) in Nakdong river basin (mainstream and its tributaries). Iopromide was detected in 16 sampling sites. The concentration levels of iopromide on February 2011 and on October 2011 in surface water samples ranged from not detected (ND) to 1481.1 ng/L and ND to 1168.2 ng/L, respectively. The highest concentration level of iopromide in the mainstream and tributaries in Nakdong river were Goryeong and Jincheon-cheon, respectively. The sewage treatment plants (STPs) along the river affect the iopromide levels in river and the iopromide levels decreased with downstream because of dilution effects.

• Journal of environmental and Sanitary engineering
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• v.23 no.3
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• pp.47-57
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• 2008

This study was predicted the diffusion of the conservative contaminant using a two-dimensional hydraulic model. The research area is upper basin of Jakwang river where the possibility where the pollutant of vast quantity will flow is high. Using SMS model, we calculated two-dimensional stream flow. And using this result, predicted the conduct of the conservative contaminant by pollutant transfer diffusion calculation. And also we predicted flow and contaminant diffusion in the near estuary by constructed guide bank. As a result of study, pollutant effect scope of the conservative contaminant was predicted with the fact that will broaden because of interception by guide bank. As discharge was increased from the Jakwang river, The diffusion of the pollutant is accelerated, also the effect scope increases.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.67-79
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• 2001

The purpose of this research is to evaluate the biotope value in a metropolitan area after constructing the biotope evaluation model to develop biotope networking in the light of ecological landscape planning. In addition this study is to provide a basic frame of constructing the biotope networking system in the future with the evaluation results. The scope of this research is limited to high density residential area including some part of the forest adjacent to urban boundary. The results of the classified biotope in the research area have been turned out to be 24 patterns. According to the result of estimated nature value having the forth grade, three were forests combined with urban natural parks, schools near forests, and grasslands. There is a little place having first grade. We an deduce this fact that we have surveyed biotopes, having the minimum nature value and wider than children's park. As for the result of evaluated the structure, there were the forests of Seong-Dong, Meaho-Dong, and Kumho river, which is the forth grade. As for the evaluation of connection-function, the followings area were evaluated as the third grade-linear biotopes having highly valued and sustainable similarity - Seoul-Pusan Railroad, Dong-Daegu St., Kumho river, river basins. Bum대 park and a botanic park near Suesung lake, As for the evaluated the buffer-function, higly valued production biotopes, existing at a transition belt between he residential density areas, are Sawol-Dong, Meaho-Dong and Kumho river. When each of the indexes was evaluated, the core of the biotop contained most of natural biotopes. Large artificial biotopes were evaluated as an important biotopes, while small artificial biotopes were classified as a dot biotope. The future research on the concrete biotope networking construction, based upon performed evaluation in this research, should be conducted.