• Water for future
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• v.17 no.2
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• pp.85-97
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• 1984

Measuring the river flow and water quality in the midstream of the Nakdong River, the natural purification status in examined through the analyses of the elements which affect the variation of dissolved oxygen, and DO model is evaluated to the midstream reach of the river. The major results of this study are as follows; the pruification factor of the of the river is relatively high, it is worried over eutrophication considering much production of algae, and it is evaluated that important factor affecting the DO value computed by the proposed DO model are in order of reaeration coefficient, carbonaceous BOD and deoxygenation constant.

• Journal of Environmental Science International
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• v.2 no.4
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• pp.291-297
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• 1993

The COD values and chloride ion concentrations of the Taewha river flowing through Ulsan area were determined along the main stream and the relationships between CODs and chloride ion concentrations were described. The results showed that the middle-upper stream and downstream of the Taewha river were polluted deeply with municipal sewage and self-purification occured in the middle-downstream of the river. When domestic sewage is a main source of pollutants, and is especially the only source of chloride in the stream water, the ratio of COD/[$\textrm{Cl}^{-}$] will be utilizable as a measure of self-purification of the stream.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.12-17
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• 2006

Natural rivers have water purification functions called Gravel Contact Oxidation Process, which decontaminate river water by biological absorption, oxidation and degradation on riverbed gravels. This function has been developed and applied to many small/medium-sized urban rivers in Japan as one of the direct river water purification methods. However the method hasn't been verified in the tropics, which have different climate conditions and river characteristics. A preliminary experiment carried out at a polluted urban tributary in the outskirts of Kuala Lumpur, Malaysia where an increasing attention has been paid to river environment, showed a good applicability to the tropical conditions as a technically practical water purification measure with some maintenance cares for sludge management.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1182-1183
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• 2005

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.127-127
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• 2017

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.39-40
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• 2009

The goal of sustainable and environmental management of Yeongsan river are maintain of water quality and have a enough a water volume and supply to the use of water purpose, we also prevent water disaster from it keep going purification, life and activity in river forever.

• Korean Journal of Environmental Agriculture
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• v.1 no.1
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• pp.39-47
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• 1982

Dissolved oxygen, BOD and flow pattern of the Nakdong River stream were measured for 3 years from 1978 to 1980 at quarterly intervals of January, April, June and October at 12 sites along the main stream from Sangju to Imhaejin and at 2 sites of Geumho and Nam River tributaries. With these data, the self-purification factors of the river were computed to obtain the following results: 1) The average BOD loads per day at the tributary of Geumho River were 94 tons in January, 39 tons in April, 60 tons in July and 54 tons in October, and these are considered to be the main source of water pollution toward the main stream of the Nakdong River. 2) Self-purification factors for the Hwawon-Hyunpung region of the main stream after receiving Geumho River water were computed to give $0.21{\sim}0.59$ of deoxygenation $constant(K_1)$ and $0.56{\sim}2.27$ of reaeration $constant(K_2)$. The oxygen-sag curves constructed for the main stream showed a remarkable decline at Hwawon and a quick recovery at Hyunpung, indicating a rapid decomposition of pollution loads received from the Geumho River. It was confirmed that the self-purification capacity of the Nakdong River was relatively high.

• Journal of Korea Water Resources Association
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• v.38 no.3 s.152
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• pp.235-244
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• 2005

This study was carried out in Osan river to quantitatively investigate behavior of attacked microbial community (AMC) for enhancing self-purification process of river. We gained the results such as follows throughout long-term monitoring at in-situ river. The biomass of AMC had higher in the riffle than the almost stagnant pool and they were more developed in the riffle with high current velocity (HCV). Although the fast flowing current affects negatively to growth of the AMC during the early phase when the community gets attached to the benthic substrate, it was observed that it affected positively to their growth during the intermediate and later phase after the community is adapted to the substrate. When turbulence due to external pressure (storm or discharge of dam and reservoir) occurs, the degree of separation depends upon the flowing strength and the type of the external pressure. Since the community is not all separated, recovery is rather fast. Therefore, this study found that the degree of reduction of the pollutant by self-purification of the stream is depended upon the riverbed shape and the AMC contributes to self-purification positively or negatively in river. Therefore, the riverbed shape must be constructed in accordance with the characteristics of water quality in stream. Furthermore, the technique of installing the water channel structure appropriate for each section must be developed to maximize self-purification ability.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.153-165
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• 2003

This study was conducted to get some information on plants abilities to enhance water purification and to find out away to conserve the ecosystem in Mankyeong river. Vegetation were surveyed at 4 sites pointing by 1:5,000 topographical map, from June 2001 through March 2002. T-N content in water were high in all sites of Mankyeong river, the average T-N levels were 8.59 and 17.23 mg/L, summer and winter, respectively. The average T-P level during summer was 0.47 mg/L but that was 1.79 mg/L during winter. The BOD level in Mankyeong upstream ranged from 0.95 to 2.57 mg/L which would be in I or II grade according to water quality criteria by Ministry of Environment but BOD level in Mankyeong downstream ranged from 6.87 to 9.72 mg/L. The plant species of river flora were found 251, 98 and 85, upstream midstream and down stream, respectively. Among the surveyed plants, Ceratophyllum demersum, submerged plant and Nuphar subinteperrimum took up higher contents of phosphate and nitrogen than other piano. The Phragmites communis and Zizania latifolia having much biomass were thought to be suitable plants for enhancement of e natural water purification.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.734-738
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• 1999

This study is to modify the EUTRO5(sub-model of WASP5) for applying river water quality simulation. Because previous version of EUTRO5 has unique kinetic constant for all segement on each constituent, EUTRO5 is not adequate for some river simulation. As this version have each kinetic constant for all segment on each constituent, it will be suitable for model application with rapid changing geometry and kinetic purification of upstream river.