• Title/Summary/Keyword: Tributary

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The Distribution of Organic Carbon and its Decomposition Rate in the Kum River, Korea (금강수계에서 수중 유기탄소의 분포와 분해속도)

  • Jang, Chang-Won;Kim, Jai-Ku;Kim, Dong-Hwan;Kim, Bomchul;Park, Ju-Hyun
    • Journal of Korean Society on Water Environment
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    • v.24 no.2
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    • pp.174-179
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    • 2008
  • The distribution of organic carbon and its decomposition rate were studied in the middle and down stream reaches of the Kum River system, Korea. Water samples were collected from May to June in 2006 at seven mainstream sites and three tributary sites from the river mouth to the Daechung Reservoir outlet. The change of DOC and POC were measured during incubation for the determination of decomposition rate. The reduction of organic carbon during 20 days' incubation was regarded as labile or biodegradable organic carbon (LDOC, LPOC), and the remaining organic carbon was regarded as recalcitrant organic carbon. The mean TOC was $5.17({\pm}1.49)mgC{\cdot}L^{-1}$ in the mainstream sites and $7.09({\pm}1.48)mgC{\cdot}L^{-1}$ in tributary sites, respectively. TOC comprised of 62% DOC and 38% POC. LPOC was approximately 68% of POC, while LDOC was only 24% of DOC. Mean decomposition rate of TOC was about $0.03day^{-1}$. Mean decomposition rates of LPOC ranged from $0.10day^{-1}$, and that of LDOC was approximately $0.08day^{-1}$. The decomposition rate of both LPOC and LDOC did not show significant difference between mainstream and tributary sites. The result of this study can give a guide to the selection of parameters in the calibration processes of water quality models.

A Study on Water Quality Changes of Geum River Subwatersheds: In Cases of Tributary (금강수계 소유역내 수질 변화 분석 -소하천을 대상으로-)

  • Han, Ah-Won;Hong, Sun-Hwa;Hwang, Soon-Hong;Kim, Dong-Ho;Lee, Jun-Bae;Lee, Young-Joon
    • Korean Journal of Environmental Agriculture
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    • v.31 no.4
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    • pp.328-343
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    • 2012
  • BACKGROUND: For effective subwatershed management, it is very important to select the tributaries for improving water quality and understand the characteristics of tributaries. Until now, however, the case study of main streams has been managed. 17 tributaries in Geum river subwatershed were monitored to regulate the source of water contaminations and identify their current situations in this study. METHODS AND RESULTS: As pollution indicators, such as biological oxygen demand($BOD_5$), chemical oxygen demand($COD_{Mn}$), suspended solid(SS), total nitrogen (T-N), total phosphate(T-P) and total organic carbon(TOC) in Geum river were examined from January to December in 2011. The results were as follows : The annual average concentration of nutrients in Yongdam reservoir upsteam was 0.7 mg/L for BOD, 3.0 mg/L for COD, 8.4 mg/L for SS, 2.905 mg/L for T-N, 0.035 mg/L for T-P and 1.6 mg/L for TOC. Water quality of Daechung reservoir upstream was mostly similar tendency in comparison to Yongdam reservoir upstream. Among the 22 tributaries, water quality in Daechung reservoir downstream was more polluted. T-N contents were significantly high in Miho B4 located Daechung reservoir downstream(annual average concentration: 13.53 mg/L). In cases of Miho A1, A2 and C1, pollution degree was worsened during rainy season expecially. CONCLUSION(S): For improving water quality of Geum river subwatershed, the tributaries in the Mihocheon area should be preferentially considered. Mihocheon tributary is the highest in pollution site, and thus a study on long-term effects should be research.

A Study on the Evaluation of Pollution Characteristics of Sincheon Stream and Its Tributaries in Gyeonggi-do Province (경기도 신천 및 유입지천의 오염특성 평가)

  • Son, Yeong-Geum;Im, Heung-Bin;Lee, Kang-Hyuck;Kim, Jin-Guil;Im, Yun-Jung;Choi, Jeong-In;Lee, Ho-Jung;Oh, Jo-Gyo
    • Journal of Environmental Health Sciences
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    • v.43 no.5
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    • pp.422-430
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    • 2017
  • he objective of this study is to evaluate and analyze Sincheon basin water environment system. The data were collected from 2010 August to 2016 December including BOD, SS, T-N, T-P. The results were as followed. As the result of comparing the amount of BOD generated by pollution sources in the Sincheon water system, industrial was the highest at 33,259.4 kg/day. In comparison with the tributary, it was estimated that Dong-Du water system reveals the highest level of BOD in the industry. Population and livestock was high in CheongDam and Sang-Pae water system. With the inflow stream of Hyo-Chon, Suk-Woo and Sang-Pae, the pollution degree of BOD and T-N level of Sincheon increased and pollution degree of tributary was higher than that of Sincheon's main stream. The main reason of pollutant of Suk-Woo was from untreated wastewater, and it influenced downstream of Suk-Woo. Hyo-Chon stream satisfy the water quality standard, but Zn was designated as a Monitoring contaminants, was high as 14.670 mg/L (standard 0.02~2.45mg/L)because of textile wastewater. And Sang-Pae stream was polluted by livestock wastewater of livestock farms as a nonpoint source.

Flume Experiments on Channel Morphology at a Tributary Junction (하천 합류점의 하도형상에 관한 수로실험)

  • Taeho Kim
    • Journal of the Korean Geographical Society
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    • v.33 no.3
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    • pp.355-364
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    • 1998
  • Flume experiments are conducted to describe the channel morphology at a tributary junction and to examine the influence of channel arrangements and hydrologic conditions on the channel morphology. When flow momenta of two tributaries are equal, a receiving stream tends to align with an axis bisecting junction angle. It causes lateral migration of a receiving stream according to an initial channel arrangement. As a result, the post-fonfluent channel morphology varies with plan geometry of a confluence such as symmetry, transition and asymmetry. Bed scour is the most notable morphology within a junction site. Its shape is characterized by steep walls which are primarily influenced by junction angle. Key control of scour dimension is also junction angle. Although the principle of accordant junction has been undoubtedly accepted, discordance is commonly developed at model and natural stream confluences. Unit discharge ratio of confluent streams is the most crucial factor because both discharge and sediment concentration ratios have an effect on discordance at a junction.

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A study on the application of River Monitoring Activities for Residents Participatory Watershed Management - Focusing on the Musim River Basins - (주민참여형 유역관리를 위한 하천모니터링 활동의 적용가능성 연구 - 무심천유역을 대상으로 -)

  • Lee, Eunjeong
    • Journal of Environmental Impact Assessment
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    • v.26 no.1
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    • pp.57-67
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    • 2017
  • Recently, Looking at the watershed management policy in Korea, It is preparing to manage sub-watershed and tributary from the government-led mainstream management, such as the selection of algae focused management tributary, application of tributary-TMDLs. At this point, this study is attempted to propose the residents participatory watershed management methods that is possible daily, voluntary and customized management in the sub-watershed. As a results, through this study, we found out the importance of sub-watershed unit based watershed management because of the pollutants in blind spot. It is the prerequisite for watershed management to arrange practicable bottom-up approach that these investigated contents can be reflected in the various planning.

Fish Community and Stream Health Assessment in Lake Chungju and its Tributaries (충주호의 어류상과 유입하천의 생태건강성 평가)

  • Choi, Myung-Jae;Park, Hae-Kyung;Yun, Seuk-Hwan;Lee, Jangho
    • Journal of Korean Society on Water Environment
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    • v.28 no.2
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    • pp.185-196
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    • 2012
  • The fish community within the lake and 5 tributaries of Lake Chungju in spring and autumn, 2009 was surveyed. In this study, the total 128,506 individuals were collected belonging to 11 families 29 genera 34 species. The most dominant species was Squalidus japonicus coreanus that account for 91.6% of population and 49% of biomass of fish community. In the point of population, dominant species were small-sized species, which became the prey of big-sized predatory species. In the point of biomass, dominant species were predatory species which were large-sized. The most dominant species in lacustrine area was S. japonicus coreanus which accounted for 92.2% of total population and 49.1% of total biomass. The most dominant species of tributary streams was Tridentiger brevispinis which accounted for 66.4% of total population and 55.1% of total biomass. The site of C3 in lacustrine area and Dongdal-cheon in tributary streams collected the most number of species. Through ecological health evaluation of five tributary streams using 8 metric index of biological integrity (IBI) model, two streams (Dongdal-cheon, Kwang-cheon were evaluated as, "B", "good" condition, and Jangsung-cheon obtained grade C indicating "Fair" condition, Jecheon-cheon obtained grade D indicating "Poor" condition based on IBI model. Lepomis macrochirus which was designated as a domestic ecosystem-disturbing alien species with wide food niche have shown tendency to increase the number of individuals since 1991 indicating the adverse effect on not only fish community but also aquatic ecosystem food web of Lake Chungju.

An Analysis on the Characteristics of Separation Zone Due to a Bed Discordance at Confluence (합류부 하상고 불일치에 의한 분리구역 특성분석)

  • Choi, Heung Sik;Mo, Sun Jea
    • Journal of Korea Water Resources Association
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    • v.48 no.8
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    • pp.625-634
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    • 2015
  • The diverse patterns of separation zone according to the marked bed discordance by dredging at confluence in addition to the confluence angle of tributary and discharge ratio between tributary and main channels have been analyzed by CCHE2D model simulation. The separation zone is defined by inside of zero velocity boundary at down-stream of confluence. The separation zone dose not formed at the $30^{\circ}$ of confluence angle of tributary. The size of separation zone increases as the discharge ratio and confluence angle increase in general. The separation zone decreases as the dredging depth increases which shows the relative momentum reduction compared by the flow volume increasing by dredging at confluence. The contraction factor with the variation of confluence angle and discharge ratio has been investigated and confirmed the corresponding conveyance decreasing results in backwater effect. The regression equation of shape factor with confluence angle and discharge and dredging depth ratios has been suggested.

Environmental Impacts of Stone Quarry Exploitation - Aquatic Macroinvertebrate Community and Quarry Locality (수생태계에 미치는 석산개발의 영향 - 생물군집과 입지유형을 중심으로)

  • Lee, Sung Jin;Kim, Myoung Chul;Kim, Ji Young;Ro, Tae Ho
    • Journal of Korean Society on Water Environment
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    • v.21 no.4
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    • pp.368-378
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    • 2005
  • Inorganic matters originated from stone quarries and manufacturing plants could alter the ecological characteristics of adjacent aquatic systems, especially the structure and function of benthic macroinvertebrate community. In such situation, the locality of stone quarry and the quantity of inorganic matters would be important factors that determined the disturbing strength to the benthic macroinvertebrate community. Locality patterns of stone quarries were classified into 3 types in relation to the stream ecosystem; stream-proximity, upstream-inclusion and tributary-inclusion type. In the result of species:abundance analysis, stone quarry B (upstream-inclusion type) showed geometric distribution, while others showed broken-stick distribution pattern. The benthic macroinvertebrate communities closer to stone quarries showed smaller species numbers and standing crops among all types of stone quarries. However the values of species evenness index were not seriously different between controls and directly affected sites. These results indicated that the effect of inorganic disturbance would differ from those of organic pollution that induced the highly dominant state occupied by tolerant species. Number of occurred species, standing crops, community indices and biotic indices indicated that the community of upstream-inclusion type was the most seriously damaged from the inorganic disturbance, and the community would be very simple and unstable. Tributary-inclusion stone quarry heavily damaged to tributary system in biologically, but influence to the main stream seemed to be depended on the scale of main stream. Among 3 types of stone quarry localities, stream-proximity type induced the least damages to benthic macroinvertebrate community, though the degrees of damage were different along with distances between stream and stone quarry.

A Study on Selection Method of Management Watershed for Total Pollution Load Control at Tributary (지류총량관리를 위한 관리유역 선정 방법에 관한 연구)

  • Hwang, Ha Sun;Lee, Sung Jun;Ryu, Jichul;Park, Ji Hyung;Kim, Yong Seok;Ahn, Ki Hong
    • Journal of Korean Society on Water Environment
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    • v.32 no.6
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    • pp.528-536
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    • 2016
  • The purpose of Total Pollution Load Control at Tributary is to obtain maximum improvement effect of water quality through finding the most impaired section of water-body and establishing the proper control measure of pollutant load. This study was implemented to determine the optimal management of reach, period, condition, watershed, and pollution source and propose appropriate reduction practices using the Load duration curve (LDC) and field monitoring data. With the data of measurement, LDC analysis shows that the most impaired condition is reach V (G4~G5), E group (flow exceedance percentile 90~100%) and winter season. For this reason, winter season and low flow condition should be preferentially considered to restore water quality. The result of pollution analysis for the priority reach and period shows that agricultural nonpoint source loads from onion and garlic culture are most polluting. Therefore, it is concluded that agricultural reuse of surface effluent (storm-water runoff with non-point sources) and low impact farming that includes reducing fertilization and controlling the height of drainage outlet are efficient water quality management for this study watershed.

Influence Analysis for Natural River Bed with Dam Construction (댐 건설이 하류하천 하상에 미치는 영향 분석)

  • Choo, Tai Ho;Chae, Soo Kwon
    • Journal of Wetlands Research
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    • v.14 no.4
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    • pp.715-723
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    • 2012
  • The Hoelyongpo in the Naeseong River as tributary basin of the Nakdong River is broadly well-known a tourist attraction, which is made of sandy beach, and is called "Island of Inland". But Construction of the Dam was planned at upstream of river. In other words, an influx of sediment is blocked from upstream of river. In this situation, through sediment discharge coming from tributary of the Naeseong river, the whether to go ahead of sand beach of the Hoelyongpo is analyzed by using 1-D and 2-D model. The sediment discharge is estimated through ratio raw with basin area, and the instream flow requirement of river coming from dam and the flow rate and sediment coming from tributary are inputted for model. The 1-D model uses HEC-6 and the 2-D model uses SMS(RMA2 and SED2D). The analysis using the HEC-6 is performed from cross section data 10 year ago to the present cross section. Consequently, Yang equation presenting similar result to the present cross section data is determined, using this, the prediction is conducted for the cross section after 20 years. The 2-D analysis is conducted for the present cross section data. The value of distinction between a deposition and erosion with the results presented in the 1, 2-D models is occur, however, the appearance between the deposition and the erosion is similar.