• Journal of Korea Water Resources Association
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• v.33 no.4
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• pp.419-426
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• 2000

It is very important to establish sufficiently long and reliable annual maximum rainfall data in estimating areal rainfall quantiles of Han River Basin. The data from 9 gauging stations measured by Korea Meteorological Administration may meet such a requirement, however the number of these data sets is too small to estimate overall areal rainfall quantiles in large basin such as Han River Basin. In order to solve such a problem, the space correlations of many sites' data measured by Korea Ministry of Construction and Transportation and Korea Water Resources Corporation (the number of sites is 59) were used for modification of rainfall measure density. And areal rainfall quantiles according to each sub-basin were estimated based on regression analysis.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.63-72
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• 2007

The main purpose of this study is that financial resources allocation criteria are examined closely between central government and local government as well as among local government in a river basin. Financial resources allocation principles reflecting water use, flood control, and water quality improvement are reviewed and derived two categories such as common factors and individual factors. The weights of each factor are assigned by analytical hierarchy process. The results of applying four river basins (Han river, Geum river, Nakdong river, Yeongsan-seumjin river) show that rational raising of financial resources are different according to the characteristics of each river basin. Findings are as follows: In case of Han river and Yeongsan Seumjin river, benefit principle and polluter pay principle by individual factors are more attractive than other Principles. Solvency principle by common factor is more acceptable than the other principles in Nakdong-river and Geum-river.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.125-130
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• 2009

Storage function method which considers the non-linearity of the relationship between rainfall and runoff has been frequently used to predict runoff in a basin and a flood pattern. However, it is time-consuming to estimate appropriate parameters of every basin and rainfall event, which requires the empirical parameter equation applicable in Korea. In this study, multiple regression analysis is used to develop empirical equations to estimate parameters of Storage Function method using basin characteristics. The basin area, maximum stream length, and stream slope are considered as the basin characteristics as the result of the regression analysis. Collinearity is removed and trial-and-error method is used to choose the most descriptive parameters to the dependent variables in Han River basin which is divided into 30 subbasins. The developed equations are validated using the rainfall events in MunMak gauging station and named as 'Han River equation'. The equation could provide the useful information about Storage Function method parameter to calculate runoff from a basin and predict river stage.

• Journal of The Geomorphological Association of Korea
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• v.27 no.4
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• pp.71-88
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• 2020

This study modified the properties and boundaries of the inland wetland types through the structural edit of the National Wetland DB, and analyzed the characteristics of the different land cover by area and the entire inland wetlands of South Korea. The inland wetlands of the Gangwon Basin had a small area of waters. In addition, the ratio of natural barren was high, reflecting the characteristics of the upper reaches of the large river in the east and west part of Gangwon Province. The Geum River Basin had a high percentage of aggregate land due to the development of large alluvial land, and the ratio of artistic barren was low, so various ecosystem service of wetland elements were distributed evenly. The Nakdong River Basin had a high proportion of waters as water level in the channel rose due to the installation of 4 Major Rivers Beam, and the ratio of Natural barren was low. Moreover, the water level of the main attributes flowing into the Nakdong River drainage system was not high, so the ratio of vegetation concentration was high. The Yeongsan River Basin showed that Waters had the high proportion. And the distribution of Natural barrens represented differently according to the Yeongsan River Basin and the Seomjin River Basin. Finally, Sand and Gravels supplied to rivers during precipitation were deposited in the main stream of the Han River Basin, and the differences between the side and high side was large in the area, reflecting the characteristics of the mouth of a river, so the Natural barren of Clay was distributed.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.889-896
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• 2007

From the direct outflow of Chungju Dam to the junction of water body and watershed in Paldang lake is the scope of this research. This study performed to investigate the main cause of water quality deterioration and the influenced region in the middle field range of the Namhan river Basin with the onsite measurement of water quality and flow rate simultaneously during spring dry season. The purpose of this study is to find out the time-spatial variation characteristics of water quality and flow rate. Following the flow direction $BOD_5$ and $COD_{Mn}$ concentration increased to the highest value of 3.7 mg/L, 5.9 mg/L at Wolgesa respectively. Chl.a concentration increased to $50mg/m^3$ or so at Kangsang, after that it decreased to $37mg/m^3$ at the junction of Paldang lake. Organic matter concentration variation trend showed similar than that of Chl.a. Also $BOD_5$ concentration tendency was similar to Chl.a in every measuring sites except Paldang lake mixing zone. The major factors of water quality deterioration in Namhan river and Paldang lake during dry season were algal bloom and followed internal production. High phosphorus load from Dalcheon and Seom river caused dry season algal bloom and internal production in transitional zone which was stagnant area in downstream of Namhan river.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.173-181
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• 2003

This study has evaluated the raingauge network of Nam-Han River Basin by assuming that the rainfall field is homogeneous in space and its spatial correlation structure is exponential. The results of the study was compared with the standard of WMO. Summarizing the results are as follows: (1) The Nam-Han River Basin is not the mountain area, nor the plain area of the WMO standard. However, the correlation length of the downstream part is longer than that of the upstream part, enough to differentiate the rainfall fields in both areas. (2) It seems that the standard for the evaluation of the raingauge network of Nam-Han River Basin should be decided to represent upper 50% of correlations derived, when the maximum intervals between neighboring gauges are estimated to be 18.2km for the upstream area and 21.1km for the downstream area. Simply evaluating the raingauge density, the Nam-Han River Basin has enough raingauges exceeding the WMO standard for the mountain area in the temperate region. (3) Evaluation of the spatial distribution of raingauges in the Nam-Han River Basin shows that its spatial distribution Is not in a proper level, especially when applying the WMO standard for the mountain area in the temperate region. However, when applying the new standard proposed in this study, only five to six more raingauges are required to be added.

• Journal of Korea Water Resources Association
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• v.41 no.11
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• pp.1143-1152
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• 2008

Korea is located in a monson area, so that 2/3 of precipitation is fallen down in rainy season and dry season has few rainfall. Also, water quality gets worse during dry season by shortage of water. In this paper, the method, which is a physical way to improve water quality by dilution through over supplied water from big reservoir or dam, is analyzed at Han-river basin. For the sake of the analysis, the basin is divided in 33 catchments and each catchments' natural flow is simulated by SWAT-K and the future water demand is estimated by using statistics data. It is considered that Han-river basin has two big reservoirs(Chung-ju dam, So-yang gang dam) and potential discharge by dam is calculated through case of supply water from each dam and supply water from both dams.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.29-36
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• 1992

Among the rivers in Korea, the Han River is the largest, most important one, which runs through the Seoul metropolitan region in the west toward the yellow sea. In the Han River basin there live as many as 17.1 mil. people including appr, 11 mil, citizens in Seoul. The Seoul Metropolitan region, already containing appr. 40% of the nation's total populating, expectedly poses an ever-growing polluting burden to the Han River. Due to Korea's vigorous industrialization and heavy urbanization in the past quarter century, water pollution was observed to be increasing in the Han River until the mid-1980's, but thereafter the Han River began to improve little by little by virtue of the government's massive investment and all-out efforts in water preservation. Public awareness on the importance of environmental protection is increasing unprecedentedly. With a view to meeting people's growing demand for clean water and pleasant environment, the government established the "Comprehensive Mid-Term Environmental Conservation Plan" (1992∼1993) in 1991. According to the plan, 1,315 bil.won(1.7 bil.us$ ) is to be poured into the Han River Basin to install 113 water pollutant abatement plants including 43 treatment facilities. To successfully cope with the future's challenging need for the environmentally sound sustainable development, a variety of measures and an array of policies are going to be incorporated with emphasis on, -redistributing such polluting sources as population and industries -tightening control of the water pollutant discharge -restricting the pollution-accompanying land use -enhancing the assimilation capacity of the river -stirring up the public awareness and participation in the environment protection We hopefully anticipate that with those e(forts the Han River will improve as drawn in the attached "1996's Envisioned Han River Quality".

• Journal of Korea Water Resources Association
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• v.53 no.7
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• pp.469-480
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• 2020

This study analyzed the differences of mean basin precipitation between TM and radar based on the 51 standard basins in Han river and Nakdong river when large scale of heavy rains occurred in 2018. The result shows that the differences between radar and TM are -65.05 ~ 26.09% and -82.00 ~ 3.80% for accumulated and 10 min. maximum mean basin precipitation, respectively. The correlation analysis between the differences of estimated mean basin precipitation and basin characteristics such as average altitude of basin, area of basin, and shape factor of basin presents that there is no clear correlation between them. And the differences of point precipitation also shows the similar tendency with those of mean basin precipitation. In order to find out the correlation between them and meteorological conditions such as rainfall patterns, the reflectivity of radars according to the observation angles is analyzed at the selected basins, and then it is found that the differences of mean basin precipitation between TM and radar is more dominated by the meteorological conditions than by the topographic conditions such as basin characteristics.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.3
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• pp.130-143
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• 1997

To investigate geochemical characteristics and the sources of the dissolved ion species in the river water in the Han river drainage basin, samples were collected at 60 sites from the Han river drainage basin. The data for. pH, conductivity, TDS (total dissolved solid), temperature, and concentrations of dissloved ions were obtained as follows : (1) The geochemical characteristics of the surface water in the South and North Han river drainage basins are mainly controlled by bed rock geology in the drainage basin and in the main stream of the Han river considerably affected by anthropogenic pollution. The South Han river water samples have high concentrations of $Ca^{2＋}$ (ave. 15.42 ppm), $Mg^{2＋}$ (ave. 2.74 ppm), HC $O_3$$^{[-10]}$ (ave. 51.9 ppm), which evidently indicates that the bed rock geology in a limestone area mainly controls the surface water chemistry. The concentration of S $O_4$$^{2-}$ is remarkably high (SHR10-2 : 129.9 ppm) because of acid mine drainage from the metal and coal mines in the upper reaches of the South Han river. (2) The South Han river and the North Han river join the Han river. in the Yangsuri, Kyounggido and flow through Seoul metropolitan city. The mixing ratio is about 60:40 at the meeting point (sample number HRl0). (3) The result of factor analysis suggests that the pollution factor accounts for about 79% and the bed rock type factor accounts for about 7% of the data variation. This means that the geochemical characteristics of the Han river water mainly controlled by anthropogenic pollution in the South Han river and main stream of the Han river drainage basin. (4) The chemical data for four tributaries such as the Wangsukcheon, the Tancheon, the Zunuangcheon, and the Anyangcheon show that the concentration of pollution elements such as N $O_2$, C $l^{－}$, P $O_4$$^{3-}$, S $O_4$$^{2-}$ and Mn are high due to municipal waste disposal.