• Journal of Environmental Science International
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• v.20 no.12
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• pp.1533-1540
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• 2011

This study was conducted to identify the sedimentation quantity and settling velocity, sediment fundamental data that an important position of water quality management of Seston, POC, PP and PN in Nakdong river basin using a sediment traps to collect suspended material pollutants. Nakdong river basin is that average sedimentation quantity of seston, POC, PP and PN were 124~1,125 g/$m^2$/d, 2,963~25,072, 26~347, 445~2,184 mg/$m^2$/d, respectively. Settling velocity of Seston, POC, PP and PN were 17.0, 35.5, 8.7, 2.4 m/d. It was appeared that various results according to the river flow, weather and other environmental factors. There was no significant correlation, each suspended material pollutants. Sedimentation rates are likely to be overestimated because the flow is not considered to resuspended materials. Therefore diversification through continued monitoring is needed to be analyzed.

• Journal of the Speleological Society of Korea
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• no.66
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• pp.95-109
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• 2005

About 30 limestone caves have already been developed at the basin of the River Dong. baekyong Cave, Hwaam Cave, and Jeolgol Cave are of great worth, not noly as a matter of study, but as a matter of the tourist resources they develop. Among them Baekyong Cave is the best. I'm going to give a full detailed account of cave deposits and cave phenomena focused on its view to preserve the looks of Baekyong Cave by analyzing the speleothem of Baekyong Cave and cave system scientifically and systematizing them. Baekyong Cave, Natural Monument Ho. 260, is on the verge of being submerged. Peculiar things in Baekyong Cave are 1) pseudo stalgmite 2) anthodites 3) erratic stalagmites 4) cave shield 5) lost river 6) cave flint 7) pit fall but I have also mentioned general and related matters.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.197-207
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• 2015

Modification of travel time is necessary in all Nakdong river basin because hydrological conditions of Nakdong river basin were changed after major rivers project. Also calculation of flood travel time at between sections of weirs is necessary. In this study, flood travel time was calculated using hydraulic model and the latest topographical data from Changnyeong-Haman weir to Nakdong river estuary bank. Analysis of discharge and stage conditions were carried out. 84 of the scenarios were organized according to flow rate, discharge type, boundary conditions, and tributary conditions. Flood travel time of initial and peak were calculated with discharge and stage conditions, respectively. The results of this study will be available in practical business work such as flood forecast warning and weir operation on algae removal.

• Journal of Korean Society on Water Environment
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• v.30 no.1
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• pp.60-67
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• 2014

In this study, four methods for calculation of continuous daily flow was suggested using short-term or partial recording station of streamflow including missing data. Using these methods, standard flows at the outlet of unit/small basins for the management of total maximum daily loads (TMDLs) in Namgang dam basin were estimated from full-period flow duration curve (FDC). Four methods of extension are described, and their properties are explored. The methods are regression (REG), regression plus noise (RPN), and maintenance of variance extension types 1 and 2 (MOVE.1, MOVE.2). In these methods, the continuous daily flow was calculated using extension equation based on correlation analysis, after conducting the correlation analysis between historic record of streamflow and long-term recording station (a base station). Finally the best optimal method was selected as the MOVE.2, and the standard flows in the abundant, ordinary, low and drought flow estimated from FDC was evaluated using MOVE.2 in unit/small basins.

• Water for future
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• v.27 no.1
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• pp.53-67
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• 1994

Water quality analysis in the midstream of the Nakdong river is studied. Deterministic model RQ1 which contains two code, RQ1-1 for hydrologic and hydraulic analysis and RQ1-2 for water quality analysis are developed. Monthly mean and minimum discharges in the basin (from Waegwan to Jindong) are estimated. A varied flow analysis is performed based on the geometric data of channel and RQ-1 model. The maximum concentration of BOD and minimum concentration of DO are occurred at the confluence of Keumho river and immediately downstream of Hyunpoong, respectively. The computed concentrations of BOD at several points have good agreements with observed data. Maximum allowable BOD loads from the Keumho River are provided to attain the goal of water quality in the basin.

• Environmental and Resource Economics Review
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• v.22 no.1
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• pp.179-214
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• 2013

This paper estimated the value of waterside landscape and ecosystem of Han River basin with a double-bound dichotomous choice type of CVM. We used the exponential willingness to pay model to represent the nonnegative willingness to pay. This model is found to be especially important in analyzing a double-bound dichotomous choice model. The total willingness to pay was estimated as 705.5 billion won per annum. This suggests that current budget size for water quality and ecosystem conservation for Han River needs to be expanded.

• Environmental Engineering Research
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• v.18 no.1
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• pp.9-20
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• 2013

In this paper, the rainfall elasticity of streamflow was estimated to quantify the effects of climate change on 5 river basins. Rainfall elasticity denotes the sensitivity of annual streamflow for the variations of potential annual rainfall. This is a simple, useful method that evaluates how the balance of a water cycle on river basins changes due to long-term climate change and offers information to manage water resources and environment systems. The elasticity method was first used by Schaake in 1990 and is commonly used in the United States and Australia. A semi-distributed hydrological model (SLURP, semi-distributed land use-based runoff processes) was used to simulate the variations of area streamflow, and potential evapotranspiration. A nonparametric method was then used to estimate the rainfall elasticity on five river basins of Korea. In addition, the A2 (SRES IPCC AR4, Special Report on Emission Scenarios IPCC Fourth Assessment Report) climate change scenario and stochastic downscaling technique were used to create a high-resolution weather change scenario in river basins, and the effects of climate change on the rainfall elasticity of each basin were then analyzed.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.63-72
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• 2010

This study aims to make a decision about the rational option for a multipurpose dams development of the Tumen river basin so that the adjoining countries will effectively deal with the chronic problems and fully satisfy the fast growing demand of water and power. It has been thus far investigated that the interests between North Korea and China closely depend on the selected option, and they are not well compatible with each other. These situations are defined in terms of the cooperative two-person nonzero-sum game. The Nash bargaining model is then applied to contemplate the rational option, considering two scenarios of economic growth of the North Korea. After analyzing the model, it was expected that 1) two multipurpose dams must be cooperatively developed, and 2) their benefits should be allocated according to demand of each country. The authors finally suggest that a cooperative organisation be established to effectively manage the dams beyond the border of the countries.

• Journal of Korean Society on Water Environment
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• v.27 no.5
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• pp.719-728
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• 2011

The results of investigation on the water quality of the unit watersheds in the Yeongsang/Seomjin River indicate that $BOD_5$, SS, T-P decrease in most of the unit watersheds. However, $COD_{Mn}$ and T-N increase since the Total Maximum Daily Loads (TMDLs). It is thought that $COD_{Mn}$, which is included non-biodegradable matters, is difficult to decrease only using by conventional biological treatment facilities and T-N is affected by non-point source, etc. The results of assessment on 3 years $BOD_5$ indicate that most of the unit watersheds were being improved except Yeongbon A, Seombon C and Yocheon B. In addition, it was found that T-P were also being improved except Yocheon B and Hwangryeong A. Consequently, water qualities of the unit watersheds have been improved in many cases since the TMDLs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.237-247
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• 2018

The basin characteristics reflect the attributes of geomorphological pattern of basin and stream networks affect the rainfall-runoff. In order to analyze the relationship between the basin runoff and stream morphometric characteristics, the morphometric characteristics were investigated for 27 water-level observation stations on 19 rivers in the Han River basin using Arc-map. The morphometric characteristics were divided into linear, areal and relief aspects for calculation while the annual mean runoff ratio as a basin response by rainfall was estimated using the measured precipitation and discharge to analyze the rainfall-runoff characteristics. The correlation among the morphometric parameters were schematized to analyze the correlations among them. The multiple regression equation for rainfall-runoff ratio was provided with morphometric parameters of stream length ratio, form factor ratio, shape factor, stream area ratio, and relief ratio and the coefficient of determination was 0.691. The RMSE and MAPE between the measured and the estimated annual runoff rates were found as 0.09, 11.61% respectively, the suggested regression equation showed good estimation.