• Journal of Environmental Impact Assessment
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• v.14 no.3
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• pp.135-145
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• 2005

This study was conducted to investigate the characteristics of meteorological environment variation before and after construction of Nak-dong river estuary barrage. We used meteorological data(air temperature, precipitation, relative humidity, visibility, wind) at Gimhae airport meteorological station. The construction of river estuary barrage can change climate at the neighboring districts and influence human's health and vegetable. The construction of Nakdong river estuary barrage brought rise of temperature, decrease of relative humidity and increase of poor visibility frequency.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.163-173
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• 2023

In this study, topographic change analysis was performed on the Nak-dong River estuary area. The factors affecting the changes in the bathymetry of the Nak-dong River estuary were analyzed using data from the discharge, suspended sediments, and rainfall of the Nak-dong River barrier as analysis data. As a result, erosion and sedimentation are judged to appear repeatedly due to complex effects such as discharge of the estuary barrier of the Nak-dong River and invasion of the open sea waves, and it is judged that there is no one-sided tendency. However, as a result of checking the data in the second half of 2020, it was possible to confirm a large amount of erosion, which is different from the past data. It is clear that this is a result beyond the trend of erosion in the first half and sedimentation in the second half. In the summer of 2020, the rainy season lasted for more than a month and torrential rains occurred, which seems to be due to about three times higher rainfall than other periods, and erosion is believed to have occurred as the discharge increased rapidly compared to the time deposited by river water outflow. In addition, compared to other times, the influence of many typhoons in the summer of 2020 is believed to have affected the topographical change at the mouth of the Nak-dong River.

• Journal of Environmental Impact Assessment
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• v.9 no.2
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• pp.143-153
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• 2000

This study was performed to investigate the heavy metal contents and distribution in soil, sediment, and rice from the downstream area of ManKyeong and DongJin River. Of the sites on Mankyeong river area, site M-1(Mokchon bridge) showed the highest average contents of Cd, Cr and Pb in paddy soil. In DongJin river area, site D-3(Munpo) and D-4(Gerjeonri) showed relatively high level of average contents of Cr, Pb and Zn in paddy soil. The average contents of heavy metals in brown rice from ManKyeong river area were 0.10mg/kg for Cd, 0.99mg/kg for Cr, 2.07mg/kg for Pb, 4.44mg/kg for Cu and 32.03mg/kg for Zn while those in brown rice from DongJin river area were 0.14mg/kg for Cd, 0.74mg/kg for Cr, 1.78mg/kg for Pb, 4.57mg/kg for Cu and 33.60mg/kg for Zn. Zn showed the highest transportation-rate from paddy soil to brown rice while Pb showed the lowest. From the results of heavy metal analysis in sediments, the average contents of Cd, Cr, Pb and Cu were generally high in site M-5(Euonri) and D-4(Gerjeonri), the most downstream sites in Mankyeong river and DongJin river, respectively.

• Journal of Korean Society on Water Environment
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• v.21 no.3
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• pp.236-241
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• 2005

The purpose of this study is to find out the source(s) and distribution of boron in Nak-dong River. In the year of 2002, the boron has been adopted as a toxic constituent for Korean drinking water standard. In this study, the analytical samples were collected at 11 stations in March, June, September and December 2002. These samples were analyzed by inductively coupled plasma-mass (ICP-MS) method. The recovery, relative standard deviation and method detection limit of the ICP-MS method for boron was $89{\sim}111.3%$, $2.21{\sim}3.81%$ and $5{\mu}g/L$, respectively. The distribution of boron was ranged $65{\sim}155{\mu}g/L$ in March, $26{\sim}125{\mu}g/L$ in June, $22{\sim}140{\mu}g/L$ in September and $50{\sim}162{\mu}g/L$ in December. The higher levels of boron were found at Kum-ho river nearby the industrial complex, which seemed to be greatly affected by domestic sewages and wastewater from the upper streams. Thus, the concentration of boron and that of other components showed strong statistical correlation in this area. In the Nak-dong River, industrial wastewater and domestic sewages is thought to be the sources of boron.

• The Korean Journal of Ecology
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• v.26 no.5
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• pp.255-261
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• 2003

To analyze ecological characteristics of the Ulmus pumila community, an on-the-spot survey was conducted in August, 1998 in the Dong River, Gangwon-do, South Korea. The Ulmus pumila community is partially distributed in Dong River's midstream and upper stream. Topographical characteristics of this community are significant in the point bar or sandbank of the river. The community is classified into two types, disturbed and non-disturbed types, by the effect of flooding. The Ulmus pumila community (bush forests of Siberian elms) is a representative community which forms riparian forests, but its distribution is rare in South Korea. Only in Dong River is the Ulmus pumila distributed enough to form a community, and none is known that is lager than this community in South Korea. The non-disturbance type progresses more homogeneously than the disturbance type because it is formed on riverside banks where it is affected less by flooding. We concluded that the Ulmus pumila community in this study area has characteristics of riparian forests. In South Korea, Ulmus pumila community can be regarded as important element of vegetation landscape constituting riparian forests. Specifically, these riparian forests are evaluated as high in conservation value due to their being formed spontaneously. Moreover, Dong River is regarded as the southern limit of Ulmus pumila, which has a northern origin. The species or community needs continuous interests and conservation countermeasures because there are limitations in its spread of distribution by natural or artificial efforts.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1188-1196
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• 2004

In this paper a determination of the optimal segment sealing material for a tunnel under the Han river between the Sungsoo-dong, Sungdong-Gu and the Chungdaw-dong, Kangnam-Gu in the Bundang railway. The geological investigation results show that some fractured zones exist loca]]y under the northern boundary of the Han river bed, but the other regions consist mostly of hard rocks of good Quality in the tunnel excavation level. Also, a hign water pressure of $5kgf/cm^2$ and a flash inflow of river water due to old boring holes are expected during tunnel excavation. A combined type sealing material of EPDM gasket with expansional rubber is selected as a optimal segment sealing material for the Han river tunnel considering the geological and site conditions.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.569-578
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• 2003

In this paper a determination of the optimal excavation method and machine type for a tunnel under the Han river between the Sungsoo-dong, Sungdong-Gu and the Chungdaw-dong, Kangnam-Gu in the Bundang railway. The geological investigation results show that some fractured zones exist locally under the northern boundary of the Han river bed, but the other regions consist mostly of hard rocks of good quality in the tunnel excavation level. Also, a hign water pressure of $5kgf/cm^2$ and a flash inflow of river water due to old boring holes are expected during tunnel excavation. A EPB shield TBM is selected as a optimal excavation machine for the Han river tunnel considering the geological and ,site conditions.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.822-828
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• 2007

Perchlorate is an unregulated contaminant but recently many cases of perchlorate contamination have been reported in the US. In Japan, also, a couple of contamination incidents caused by perchlorate occurred. Against this backdrop, investigation on perchlorate was urgent for Korea. Accordingly, perchlorate investigation in tap water and river water was conducted one time a week for seven consecutive weeks at major water sources of Korea including Han River, Guem River, Yeong-san River, and Nak-dong River. Perchlorate was not found at Han River, Guem River, and Yeong-san River. However, all the 4 tap water samples in Nak-dong River recorded high level of perchlorate. Among others, NT1 located at Daegu posted the highest value of $22.3{\mu}g/L$. This level is lower than $24.5{\mu}g/L$, the threshold recommended by US EPA. Still, perchlorate contamination in drinking water can deal a heavy blow to nerve development of infants and children by causing iodine deficiency. At the 1st and 2nd investigations, perchlorate concentration reached $18.7{\sim}95.6{\mu}g/L$ and $4.0{\sim}25.6{\mu}g/L$ respectively, both of which are relatively higher. The high perchlorate concentration in Nak-dong River was possible because of the waste water discharged from LCD manufacturing factory which was located at NS3 in Gumi, Korea. Perchlorate concentration of waste water from the factory was $730{\sim}1,858{\mu}g/L$.

• River and Culture
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• v.5 no.2
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• pp.47-49
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• 2009

• River and Culture
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• v.10 no.3
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• pp.116-121
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• 2014