• Journal of Korea Water Resources Association
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• v.44 no.4
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• pp.315-325
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• 2011

There are not many practical measures to solve a water conflict, when a hydromorphologically asymmetric situation in international rivers exists whereby downstream users may not affect upstream users but upstream users do cause downstream impacts. In taking advantage of this merit, North Korea has built Imnam Dam in upstream of North Han River and uses water for trans-basin hydropower generation. As an impact of this dam South Korean' area as a downstream user has been suffered from water deficit and dry river. It is very critical for South Korea to solve a key problem such as water allocation for water supply and river maintenance. Therefore, this study is aim to suggest alternatives for equitable water allocation in consideration of special circumstances between the South and the North. For this, reviewing the allocation methods of water rights is carried using lessons obtained from international river cases. The results show that the minimum desired streamflow is calculated at 7.3 $m^3/sec$; water budget analysis by the equitable distribution of streamflows at the border line of the North Han River, the difference in water supply deficiency is at 3.7 $m^3/sec$ before and after Imnam Dam; in the determined distribution method, the difference in water deficiency is at 11.38 $m^3/sec$. These results show that South Korea should be secured 11.38 $m^3/sec$ from North Korean's Imnam Dam in respective of water use right and sound river maintenance.

• Journal of the korean society of oceanography
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• v.33 no.3
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• pp.64-70
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• 1998

Forty sediment samples from Kyeonggi Bay, Korea were analyzed for butyltins, including tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) to determine their distribution and source in this area. Total butyltin concentrations in Kyeonggi Bay sediments ranged from 0.8 to 297 ng/g dry wt. with a mean value of 38 ng/g. The highest butyltin concentration was found in the innermost site in Incheon Harbor basin. The mouth of Han River had higher butyltin levels in sediments compared to open ocean. Butyltin levels correlated well with organic carbon content of sediment, but the major factor was the distance from the source area where antifouling paints were used for vessels and marine structures. Butyltin concentrations in the study area were lower than those reported for bays in other parts of the world. Considering the high toxic potential and sediment/water partition coefficient of TBT, further studies are needed to assess its biological effect in the marine ecosystem of Kyeonggi Bay.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.474-477
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• 2005

The Industrial development and the Increase in population have brought out a rapid increase of wastewater discharge. To deal with this matter, much estimate has been spend on construction and management of a large scale sewage treatment plant. Although every effort has been carried out, river water quality has no significantly improved. Especially. the aggravation of the water quality in dry season is brought out a serious social problem. The purpose of this study Is the development of an optimal water quality management technique considering the efficient control of the multiple pollutant load associated with the total pollutant load control. A GUI(Graphical User Interface) system named 'QL2-XP' model is developed by object-oriencted language for the user convenience and practical usage. Suggested GUI system consist of hydraulic analysis. water quality analysis, optimized model calibration processes, and postprocessing the simulation results.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.319-320
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• 2011

Lax-Wendroff 기법을 기반의 천수방정식에 대한 유한요소 모형을 낙동강 상류부 단호교 지역에 적용하였다. 모형의 검증을 위하여 이동경계에 대한 Thacker (1981)의 정확해와 침수-노출 기법(wet-dry scheme)을 이용한 본 모형의 수치해를 비교하여 대체로 잘 일치함을 알게 되었다. 또한, U자형 만곡부를 포함한 수로의 흐름에 적용하여, 기존의 수리실험 결과, 수치모의 결과와 비교하고, 모형의 적용 가능성을 확인하였다. 낙동강 상류지역에 위치한 단호교 지역에 본 모형을 적용하고, 이를 기존 유한차분법에 의한 수치해와 비교하였다.

• 한국해양학회지
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• v.16 no.1
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• pp.24-30
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• 1981

In order to investigate water pollution of heavy metals in the Nagdong Estuary, samples were collected five times from August 1978 to April 1979 every other month, and analyzed for Cd, Cu, Pb and Zn by atomic absorption spectrophotometry. The results showed no significant heavy metal pollution in most parts of the studied areas, except near the outfalls of the Sasang Industrial Complex. In general, the heavy metal contents were higher in the dry season than in the rainy season due to the dilution effect of river water flow. Distribution of heavy metals in the dissolved and the particulate fractions were also investigated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.257-260
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• 2002

The main purpose of this research is to find suitable treatment methods of wastewater effluent for artificial recharge. For this purpose, we search the effluent quality of wastewater treatment plant and possibility of additional filtration process. Particles ranged 2 ~ 5 ${\mu}{\textrm}{m}$ and 15~20 ${\mu}{\textrm}{m}$ in "T" WWTP(Waste Water Treatment Plant) effluent were relatively dominant. In dual-media filtration system operation, head-loss development of column 1 was about two times faster than column 2, and head-loss development within 5 cm from surface was very important factor in operation, Conclusively, for the stable filtration and running time of 1.5~2 day, influent turbidity must keep 5 NTU or below, and filtration system must operated at 280 m/day or below. After filtration of WWTP effluent, water quality reached satisfactory level. This water has potential of agricultural reusing, flushing water in building, recharging water to river or stream at dry season and artificial recharge of ground water.und water.

• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.172-176
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• 2008

To develop a potent strain for the production of coenzyme $Q_{10}$, a photosynthetic bacterium was isolated from silt of the Nakdong River in Korea. Using l6S-rDNA sequence analysis, the isolated strain was identified as Rhodobacter sphaeroides. A stable improvement in its $CoQ_{10}$ content was achieved by chemical mutation, upon which the content of $CoQ_{10}$(2.94 mg/g dry cell) was increased by approximately 1.9-fold, comparable to that of R. sphaeroides reported in other studies. The isolate is a potentially valuable microorganism for mass production of $CoQ_{10}$, and may provide an appropriate model for further study of economical mass production.

• Animal cells and systems
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• v.2 no.2
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• pp.165-176
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• 1998

Seasonal changes in microzooplankton abundance were identified in the mesohaline Chesapeake Bay and several tributaries from July 1992 through December 1995. Ciliates numerically dominated, comprising over 90% of the total microzooplankton density and aloricate ciliates usually outnumbered loricate ciliates. Copepod nauplii accounted for the highest microzooplankton biomass (>75% in dry weight). Rotifers made small contributions to the total microzooplankton density and biomass (<5%). Time series analysis indicated a twelve month cycle in microzooplankton abundance, and mid-summer(August) peaks for copepod nauplii, and a spring through fall peaks (May-October) for ciliates. Rotifers showed two seasonal peaks: one in mid-summer(August) at the river stations and the other in mid-winter(February) at the mesohaline stations. Seasonal peaks of copepod nauplii and rotifers coincided with the mesozooplankton abundance peak. On the other hand, ciliate maximum usually occurred between the phytoplankton and mesozooplankton peaks. This pattern of microzooplankton seasonality suggests the intermediate trophic role of microzooplankton (especially ciliates) between the phytoplankton(especially picophytoplankton) and mesozooplankton in Chesapeake Bay and its tributaries.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.159-163
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• 2011

천수방정식에 대한 Lax-Wendroff 기법을 기반으로 한 유한요소 모형을 낙동강 상류부 단호교 지역에 적용하였다. 모형의 검증을 위하여 이동경계에 대한 Thacker (1981)의 정확해와 젖음-마름 기법(wet-dry scheme)을 이용한 본 모형의 수치해를 비교하여 대체로 잘 일치함을 알게 되었다. 또한, U자형 만곡부를 포함한 수로의 흐름에 적용하여, 기존의 수리실험 결과, 수치모의 결과와 비교하고, 모형의 적용 가능성을 확인하였다. 낙동강 상류지역에 위치한 단호교지역에 본 모형을 적용하고, 이를 기존 유한차분법에 의한 수치해와 비교하였다.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.658-665
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• 2008

One of the characteristics of fluvial river channel with sand bed-material is the existence of movable sand bars not occupied with vegetation. However, sand bars at the Hahoe's reach of the Nakdong River showing a double-meandering channel has been changed into expanding vegetation area. Moreover, sand material, in recent years, has stopped moving to downstream in channel and the number and area of bare bars which did not occupied by vegetation have been decreased. In order to find out the mechanism, we carried out the channel characteristics surveys such as hydro-geomorphologic, soil physio-chemical and vegetation surveys were conducted twice on autumn season in 2005,2006. The results so far achieved showed that the reduced discharge of transported sediment and duration of dry season might be critical factors for the spread of luxuriant vegetation. The vegetation area was significantly expanded by floods exceeding the subsequent dominant flow discharge. Furthermore, the expansion of vegetation area was highly correlated with the supply of organic matter, nutrients and alteration of soil texture by sediment deposition during the flooding event.