• Title/Summary/Keyword: midstream

Search Result 135, Processing Time 0.026 seconds

An Analysis of Long-term Changes in Water Quality of Geumho River using Statistical Techniques

  • Jung, Kang-Young;Cho, Sohyun;Ha, Don-woo;Kang, Tae-woo;Lee, Yeong Jae;Han, Kun-Yeun;Kim, Kyunghyun
    • Journal of Environmental Science International
    • /
    • v.27 no.10
    • /
    • pp.883-899
    • /
    • 2018
  • In this study, water quality data of eight main sites in the Geumho River watershed were collected and analyzed for long-term changes in water quality over the period from 2005 to 2015. The results showed that BOD concentration was gradually improved by the Total Maximum Daily Load (TMDL), stages 1 and 2. Recently, a tendency of increasing BOD concentration was observed in the downstream section of the river. The concentration of COD was analyzed to be contaminated throughout the water system regardless of the water quality improvement project, and the TN concentration tended to increase in the midstream of the river from 2013. The TP concentration has clearly decreased from 2012 after the second stage of TMDL. For the statistical analysis of PCA ordination, monthly water qualities (pH, DO, Electrical Conductivity (EC), Water Temperature (WT), BOD, COD, TN, TP, TOC, and SS) and flow rate data for 5 years from 2012 to 2016 were used. Seasonally the Geumho River showed an increase in the TN concentration at point sources during the dry season (December to February). TP showed the effect of non-point sources in the summer, because rainfall has caused a rise in flow rate in the upstream. Besides, the origin of pollution source was changed from non-point sources with BOD, COD, and TOC.

A Study on Exploring Accumulation Zone and Composition Investigation of Floating Debris in Nakdong River Basin (낙동강 유역 부유쓰레기의 집적 구간 탐색 및 성상 조사 연구)

  • JANG, Seon-Woong;KIM, Dae-Hyun;CHUNG, Yong-Hyun;YOON, Hong-Joo
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.18 no.2
    • /
    • pp.45-58
    • /
    • 2015
  • The aim of this study is to find out major accumulation zones through field survey and moving route tracking trials on floating debris of Nakdong River. It also identified composition and accumulated amount of the floating debris by sample survey for accumulation zones. As a result, total 5 accumulation zones were selected from the midstream and downstream of the Nakdong River. There was a large amount of floating debris, including vegetation debris, in the accumulation zones. And two accumulation zones located in the downstream region, it is much more likely to flow into the ocean along river. From the sample survey on the major accumulation zones, more than $40{\ell}$ of floating debris were collected including vegetation and artificial debris. As a result of composition analysis for artificial debris, plastic(49%) and styrofoam(36%) were the majority in number. The present study is expected to help to plan an efficient pre-collecting activity and to reduce floating debris flowing into the ocean from the Nakdong River.

Structural Characteristics and Maintenance Mechanism of Ulmus pumila Community at the Dong River, Gangwon-do, South Korea

  • Choung, Heung-Lak;Kim, Chul-Hwan;Yang, Keum-Chul;Chun, Jae-In;Roh, Huan-Chuen
    • The Korean Journal of Ecology
    • /
    • v.26 no.5
    • /
    • pp.255-261
    • /
    • 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.

An Analysis of Changing River Sections Using GIS Spatial Analysis - Nonsan River - (공간분석기법을 이용한 하천단면 변화분석 - 논산천을 대상으로 -)

  • Lee, Jae-Yil;Lee, Gyu-Sung;Ha, Sung-Ryong
    • Journal of Environmental Impact Assessment
    • /
    • v.19 no.1
    • /
    • pp.91-97
    • /
    • 2010
  • The systematic data management system in the area of river flow analysis has not yet constructed, even though the need is evident due to the complicated process of tremendous input/output data in the modeling study and the importance of visualization of spatial flow variation. The objectives of this study are to suggest the method for analysis of changing river sections affecting ecological habitat characteristics. The effects of ecological habitat characteristics are assessed with respect to changing river sections. A GIS special analysis is created representing in the past section of Nonsan-river using historical data. Topographic surfaces are subject to erosional and depositional forces that a specific set of surface characteristics unique to elevation data. GIS spatial analyst is used to generate surface grids from historical point data. Using the GIS spatial analyst can be constructed sections for anywhere of river. The change of depth between 1979 and 1988, the left bank elevations of a river are increased about 1.5m. But the right bank elevations of a river are decreased about 2.3m caused by erosion. In addition, the change of spatial between 1988 and 2002, the regions of a river from upper stream to midstream are decreased the elevation. But the downstream regions are increased the elevation. These changes are analyzed in GIS program to assess methods for affecting ecological habitat.

Syntaxonomy and Distribution Characteristics of the Herbaceous Vegetation on Running Waterside in the Main Stream of Geumho River, Daegu and Gyeongsanbuk-do, Korea (금호강(대구, 경북)본류에서 유수변초본식생의 군락분류와 그 분포특성)

  • Lee, Ho-Joon;Choung, Heung-Lak
    • Korean Journal of Environmental Biology
    • /
    • v.19 no.4
    • /
    • pp.239-247
    • /
    • 2001
  • The Herbal Vegetation on Running Waterside in the Main Stream of Genmho River, Daegu and Gyeongsanbuk-do, Korea was investigated by the methodology from June to August of 1994 and analyzed distribution characteristics of vegetation that was related Water Environment. The vegetation is divided into 6 communities of Persicaria sieboldi-Persicaria hydropiper community, Persicaria thunbergii community, Impatiens textori community, Zizania latifoloa community, Phragmites communis community and Echinochloa crus-galli var. oryzicola community. A BOD and COD that indicate degree of contamination in water were showed 0.9 ppm and 1.6 ppm at upstream and 15.9 ppm and 24.8 ppm at downstream, respectively. The distribution patterns of vegetation have dominated by Impatiens textoricommunity in the upstream, by Persicaria sieboldi-Persicaria hydropiper community from upstream to mid-upstream, by Persicaria thunbergii community from upstream to midstream, by Zizania latifoloa community from nidstream to mid-downstream and by Phragmites communis community and Echinochloa crus-galli var. oryzicola community from mid-downstream to downstream. Especially, I suggested that Persicaria sieboldi-Persicaria hydropiper community and Persicaria thunbergii community will use as biotic indicator in water environment.

  • PDF

Future Image of Fashion Industry According to Level of Consumer Knowledge and Anxiety Level of the 4th Industrial Revolution (4차 산업혁명에 대한 소비자의 지식수준과 불안수준에 따른 패션산업의 미래이미지)

  • Seo, Sangwoo
    • Journal of Fashion Business
    • /
    • v.22 no.4
    • /
    • pp.130-144
    • /
    • 2018
  • This study aims to examine the future image of the fashion industry according to the level of consumer knowledge and anxiety about the 4th industrial revolution. An online survey was carried out from March 13 to 23, 2018. A total of 698 consumers participated in the survey. The results of the study are as follows. The consumer knowledge level about the 4th industrial revolution was 10.2% for the first recognition, 48.3% for the term recognition, and 41.5% for the content understanding. The level of consumer anxiety about the 4th industrial revolution was 36.5% lower than average and 63.5% higher than the average. An ANOVA was conducted to confirm the anxiety according to the knowledge level of the 4th industrial revolution. The results revealed that consumers with higher knowledge level felt more anxiety than consumers with a lower level of knowledge. Consumer's knowledge level about the 4th industrial revolution did not affect the future image of fashion industry and individual phases of the fashion industry. Consumer's anxiety level about the 4th industrial revolution had a partial influence on the future image of the fashion industry and on each phase of the fashion industry. In the midstream and downstream areas of the fashion industry, significant differences were observed in the future image according to the level of anxiety.

Assessment of Fecal Pollution and Bacterial Community Structure in Restored Section of Cheonggyecheon Stream (청계천 복원구간 내 분변오염도 평가와 미생물 군집 연구)

  • Park, Youngbin;Lee, Heetae;Kim, Seiyoon;Ko, GwangPyo
    • Journal of Korean Society on Water Environment
    • /
    • v.25 no.1
    • /
    • pp.76-83
    • /
    • 2009
  • In 2005, the 5.84-Km length of Cheonggyecheon stream, previously covered with concrete road, was uncovered in the middle of Seoul, Korea. We investigated microbial water quality in various sites in Cheonggyecheon stream. We took water samples on three different days. The sampling sites included inflow water from upper stream (Mojeongyo), midstream (Ogansugyo), and downstream (Muhakgyo). Fecal pollution indicator microorganisms were measured by both IDEXX $Colilert^{(R)}$ and $Enterolert^{(R)}$. Microbial community from these sampling sites was also characterized based on 16S rRNA gene sequences. The average concentrations of total coliform are 5 CFU/100 mL, 1474 CFU/100 mL, and 1776 CFU/100 mL at Mojeongyo, Ogansugyo, and Muhakgyo, respectively. The average concentrations of fecal coliform were 28 CFU/100 mL, 47 CFU/100 mL in Ogansugyo, and Muhakgyo, respectively. The concentrations of other fecal indicator microorganisms including E. coli and Enterococcus sp. increased in downstream. When we characterized the microbial community, unique microbial community were discovered at different sampling sites. This study suggests that Cheonggyechoen stream is likely affected by non-point fecal sources and has unique microbial environment as the river flows downstream.

Study of Freshwater Fish Fauna and Distribution of Introduced Species of Mankyeong River, Korea (만경강의 담수어류 및 외래어종의 분포)

  • Lee, Wan-Ok;Kim, Kyeong-Hwhan;Kim, Jong-Hwa;Hong, Kwan-Eui
    • Korean Journal of Ichthyology
    • /
    • v.20 no.3
    • /
    • pp.198-209
    • /
    • 2008
  • During studies of the fish fauna and communities of Mankyeong River, which flows to the Yellow Sea, 14 families in 44 genera and 63 species of freshwater fishes were caught. Zacco platypus (27.7%) was the dominant species and Z. koreanus (11.3%) the subdominant species in this river. Twenty-three species of Korean endemic fishes appeared, and two of these, Pseudopungtungia nigra and Liobagrus obesus, represented endangered Korea species. Community structure of each branch stream was stable, showing appropriate dominant species: Z. koreanus in Jeonju Stream, Z. platypus in Kosan and Soyang Streams, and Carassius auratus in Mankyeong main stream. Three introduced species appeared: C. cuvieri, Micropterus salmoides, and Lepomis macrochirus. Among these introduced species, M. salmoides expanded its territory from midstream to downstream because of its strong carnivorous tendency and it favoring of lentic waters. This distribution of M. salmoides affected the number and distribution of small native freshwater fishes, especially those in the subfamily Acheilognathinae.

An Experimental Study on the Depth Variation of Water Flow on Steep Open Channel with Constant Width (一定幅 急傾斜 開水路上을 流動하는 물의 깊이 變化에 관한 實驗的 硏究)

  • 박이동
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.10 no.1
    • /
    • pp.86-95
    • /
    • 1986
  • A study on film water flow on steep open channel has been seldom found up to date. Therefore, this paper dealed with the depth variation of film thickness of water (city supply normal water) flowing on steep open channel. For this purpose, Experimental apparatus (made of a normal glass with 160cm of length and 15cm of width) was made and the depths of the water flowing on the channel were measured experimentally, changing the channel slope angle from 30 to 80 degree (5 steps) and the flow rate from 0.25 to 10CPM (11 steps). The results obtained, some characteristics of the film flow on the channel are as follows. (1) When thin film water flowed on steep open channel, the depths of flow tended to increase after decreasing and was kept nearly constant in its downstream in case of laminar and transitional flow region. The turining point of the depths of flow from decrease to increase tended to move downward with the increase of Reynolds number. In turbulent flow region, the depths of flow showed reapid decrease in its upper stream, gradual decrease in its midstream and were kept nearly constant in its downstream. (2) While the differences between the depths of flow along the channel slope got small in its upper stream and got large in its downstream in case of laminar flow region, they got very large in its upper stream and were kept nearly constant in its downstream in case of transitional and turbulent flow region. And the move flow rate increases, the more the differences between the depths of flow along the channel slope got large in its upper stream.

Hematuria Screening Test for Urinary Bladder Mucosal Infiltration in Cervical Cancer

  • Chuttiangtum, Ayuth;Udomthavornsuk, Banchong;Chumworathayi, Bandit
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.10
    • /
    • pp.4931-4933
    • /
    • 2012
  • Objective: To determine the diagnostic performance of hematuria as a screening test for urinary bladder infiltration in cervical cancer patients with a prospective study design. Materials and Methods: Newly diagnosed cervical cancer patients at Srinagarind hospital from 14 June 2011 to 30 April 2012 were enrolled in this study. We collected midstream urine samples for urinalysis from every patient before routine cystoscopic exam for clinical staging. The presence of 3 or more red blood cells (RBCs) per high power field was defined as positive for hematuria. A two-by-two table was used to determine the diagnostic performance of hematuria to detect urinary bladder mucosal infiltration using cystoscopy and biopsy as the gold standard. Result: A total of 130 were patients included, 54 of which (41.5%) had hematuria. Of these, four patients (3.08%) had pathological report from cystoscopic biopsy confirmed metastatic squamous cell carcinoma. The sensitivity, specificity, PPV, NPV, and accuracy of hematuria as a screening test to detect urinary bladder mucosal infiltration of cervical cancer were 100%, 60.3%, 7.4%, 100%, and 61.5%, respectively. There was no single case of urinary bladder mucosal infiltration in patients initially staged less than stage III. Conclusions: Hematuria can be used as a screening test to detect urinary bladder mucosal infiltration of cervical cancer. This can reduce the number of cervical cancer patients who really need to undergo cystoscopy as a staging procedure to less than half and to less than 20% if stage III or more were included without missing a single case of urinary bladder mucosal infiltration.