• ALGAE
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• v.18 no.2
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• pp.157-167
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• 2003

Effect of the effluent of the sewage and wastewater plants on the algal growth was investigated from the 19 plants located in the Nakdong river basin. Most of the samples showed high values of the algal growth potential (AGP) when they were mixed with natural river water at 20% of final concentration. At 20% of the mixing ratio, the mixed effluents of sewage and wastewater showed 3.5 and 1.8 times higher AGP than those of the natural river water. The higher AGP values are attributable to the high contents of phosphorus and ammonium in the effluent. The mixing ratio of effluents of the discharge/river flow was highest in the Kumho River (42.8%) followed by the middle of Nakdong River (22.7%), Kam Stream (13.9%), Byungsung Stream (13.3%), Yangsan Stream (7.9%), and Young River (5.4%). Comparison of the trophic state of the effluents with natural river water indicated that the effluents showed higher trophic values than natural water. Concentrations of total phosphorus, total nitrogen and conductivity in the effluents were 12.3, 4.9 and 5.3 times higher than the those found in natural river water respectively. The AGP values were highly related with the trophicity of the water especially on the concentrations of phosphate and ammonium. Toxicities of the treated sewage water, wastewater and livestock waste water tested by the luminescent bacteria, Vibrio fischerii were generally low.

• Journal of Korea Water Resources Association
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• v.45 no.9
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• pp.943-957
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• 2012

In this study, a technique based on Fractal Theory with Erosion Model was developed to interpolate the river morphology data at the border area between river bed and river side where both surface and under water surveyings can not be committed easily. Three dimensional river morphology data along the Ara River was generated by the developed technique. The Ara River is an artificially constructed waterway for vessels between the Han River and West Sea of Korea. The result was compared with the survey data by RMSE of 0.384, while the IDW interpolation result has RMSE of 0.802. Consequently, the developed river morphology data interpolation technique using Erosion Model based Fractal Theory is conceived to be superior to the IDW which has been generally used in generating the river morphology data.

• Journal of Environmental Science International
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• v.16 no.2
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• pp.203-210
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• 2007

The delivery load data obtained from Nakdong river basin are used for developing the model estimating the daily delivery load on the main side streams of Nakdong River. The developed model assesses the daily contamination loads of the main thirteen side streams that contribute to the main stream of Nakdong river. It is developed that the model using the simplified equation that can estimate the daily delivery loads on the side main streams of Nakdong river for a period of having no data of the water quality and flow. The developed model for estimating the daily delivery loads from the main side streams in Nakdong river basin on each item such as BOD, TN, and TP is expressed as Daily delivery load ($\frac{kg}{day}$) = Production load $(\frac{kg}{day}){\times}(1-{\alpha}){\times}(\frac{daily\;runoff}{average\;runoff\;per\;year}){\gamma}$. The estimated values obtained by using the model are almost fit to the calculated values (real data) that have been acquired from the thirteen main side streams in Nakdong river basin. The correlation coefficient values, R, that indicate the correlation between the estimated and the calculated show over 0.7 that mean the estimated values from the used model are adapted to the real data except TN values of Nam-river, Hwang-river, Gam-river, We-river. Especially, the correlation of TP values between the estimated and the calculated implies quite a creditable data to use.

• Journal of Environmental Impact Assessment
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• v.19 no.1
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• pp.91-97
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• 2010

The systematic data management system in the area of river flow analysis has not yet constructed, even though the need is evident due to the complicated process of tremendous input/output data in the modeling study and the importance of visualization of spatial flow variation. The objectives of this study are to suggest the method for analysis of changing river sections affecting ecological habitat characteristics. The effects of ecological habitat characteristics are assessed with respect to changing river sections. A GIS special analysis is created representing in the past section of Nonsan-river using historical data. Topographic surfaces are subject to erosional and depositional forces that a specific set of surface characteristics unique to elevation data. GIS spatial analyst is used to generate surface grids from historical point data. Using the GIS spatial analyst can be constructed sections for anywhere of river. The change of depth between 1979 and 1988, the left bank elevations of a river are increased about 1.5m. But the right bank elevations of a river are decreased about 2.3m caused by erosion. In addition, the change of spatial between 1988 and 2002, the regions of a river from upper stream to midstream are decreased the elevation. But the downstream regions are increased the elevation. These changes are analyzed in GIS program to assess methods for affecting ecological habitat.

• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.540-550
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• 2013

Temporal increase of SS induces concentrations in various forms of organic matter including BOD, COD, TOC. Consequently, it causes hard to identify sources of water pollution during or after precipitation. The objective of this study is to investigate variations of DOC concentration caused by increase of flow and changes of external factors in river by comparing to SS concentration. In results, monitoring sites (e.g., Banbyeonchen) consisting of hard riverbed showed high correlation between SS and organic matters, except BOD. On the contrary, other sites (e.g., Naesungcheon) where riverbed consists of sand were found in a wide range of annual fluctuation in SS level, whereas these sites showed a narrow range in annual DOC fluctuation. In Gumhogang and Namgang, a lower correlation between SS and other factors was found most likely because of high concentration in organic matter. However, lower annual fluctuation values of DOC were observed in comparison to those of COD and TOC. Similar results were also confirmed in main river sites, Sangju and Mulgeum. In conclusion, DOC concentration is better indicator for monitoring organic matter which cannot be provided by BOD, COD, TOC in the Nakdong river basin.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.492-496
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• 2005

River is characterized by its transboundary flow not recognizing human political, administrative, and social boundaries. Water management is also strongly connected to land management. Those features reflect emerging difficulties in managing contemporary water resources. This study consists of three parts to identify theoretical concept of river management and to show how river management has differently practiced in South Korea and the United States. In part one, the Korean case shows the water quality oriented river basin management in the 1990s. The second part reveals the disappearing pattern of river basin management and the spreading watershed movement in the United States. The final part compares basin-scale river management practices of the two countries and evaluates the differences between them. The United States concentrates more on watershed management rather than river basin management while South Korea understands that both river basin and watershed are important. Therefore, the Korean case is recognized as more complicated than the American case.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.1 s.120
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• pp.28-35
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• 2007

The purpose of this study is to evaluate the visual preference factors for river scenery, which can vary according to changes in water levels, to estimate the optimal ratio of water surface/river width. Five locations on the Youngsan and Sumjin Rivers were selected as representative samples and field survey data such as channel geometry with water levels were prepared to develop the slide of river scenery, To estimate the level of satisfaction in river scenery, slides of 4 different water levels at each of the representative locations were developed through questionnaire. To analyse the correlation between the visual preference for river scenery and preference factors, a multi regression analysis method was adopted in this study. According to the results of the multi regression analysis, Factor B(Aesthetic factors) have the greatest affect on visual preferences and Factor A(A Feeling of Open space and Physical factors) affect significantly to visual preferences for river scenery. The results of analysis shows that the most preferred W/B ratio varies from 0.5 to 0.7 and this result indicates that many people prefer high levels river flow to maintain a natural and harmonious view of rivers. The results of this study will contribute to the field of river landscape design and river restoration projects in order to maximize the human being's satisfaction as a part of nature.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.213-217
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• 1999

The river bank is one of the most important structure of fluvial hydraulic structure. Because the breaking of river bank is the cause of calamity, the durability and stability of river bank an very important factors. The breaking of river bank is the cause of the overflow of flood and the leakage of river bank. In this study, we investigated the leakage of river bank using the resistivity probing and estimated the volume of leakage using the weighted residual method The study basin of this study is the upstream of Sumji river basin and the factor of river bank is length 300 m and berm 2.0 m and width 4.5 m and height 4 m. We evaluated the leakage of river basin using using the resistivity probing and estimated the leakage volume using the weighted residual method. The result of this study, the leakage of river bank generated at the point of 39~45 m 80~90 m. 218~222 m. 214~250 m and the type of leakage is the rectangle and the polygon. And the leakage volume of this points evaluated 2.7$\times$$10^{-3}$ $\textrm{m}^3$/sec.

• Journal of the Korean association of regional geographers
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• v.11 no.1
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• pp.40-53
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• 2005

The Yeongsan River had played an important role as s waterway, but in 1981, the Yeongsan River Estuarin Barrage had been constructed, the waterway had been cut off. Since then, in the lower Yeongsan River basin, discussions about the waterway restoration and its utilization of the Yeongsan River has been proposed. But these discussions have not been examined thoroughly with geomorphological and hydrological characteristics of river charmel The waterway restoration and its utilization in the Yeongsan River should be based on scientific validity. In case of considering the conditions of the Yeongsan River, it is desired that the small ship for environmental survey and ecotourism is navigable from Gujinpo to Yeongsan River Estuarin Barrage by dredging a parts of river channel. To devise a plan about restoration and its utilization of waterway, it is necessary that regional and local governments, related administrative agencies, specialists, and NGO should develop the participation and cooperation systems based on governance.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.437-441
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• 2009

The modern times is as special as from the river, the river is very important of our life. The importance to preserve the river environment has been issued and the river developing method is being changed to use potential function of nature as well as flood control. Essential element of the river restoration is a vegetation. The flow resistance by vegetation along the river banks is greatly increase the flood stage. Therefore, the flow resistance due to vegetation in the river and roughness coefficient changes to understand the hydraulic characteristics is an important elements in the river restoration. The purpose of this study is to analyze the flood stage and the aspects of riverbed changes due to the corridor restoration with river vegetation. In order to simulate the flood stage and riverbed changes, HEC-RAS, RMA-2, and SED-2D model were applied for the upstream and downstream in study reaches, respectively.