• Title/Summary/Keyword: Tributary

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Proposed approach for determination of tributary areas for scattered pressure taps

  • Aly, Aly Mousaad
    • Wind and Structures
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    • v.16 no.6
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    • pp.617-627
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    • 2013
  • In wind load calculations based on pressure measurements, the concept of 'tributary area' is usually used. The literature has less guidance for a systematic computational methodology for calculating tributary areas, in general, and for scattered pressure taps, in particular. To the best of the author's knowledge, there is no generic mathematical equation that helps calculate the tributary areas for irregular pressure taps. Traditionally, the drawing of tributary boundaries for scattered and intensively distributed taps may not be feasible (a time and resource consuming task). To alleviate this problem, this paper presents a proposed numerical approach for tributary area calculations on rectangular surfaces. The approach makes use of the available coordinates of the pressure taps and the dimensions of the surface. The proposed technique is illustrated by two application examples: first, quasi-regularly distributed pressure taps, and second, taps that have scattered distribution on a rectangular surface. The accuracy and the efficacy of the approach are assessed, and a comparison with a traditional method is presented.

Selection Priority of Tributary Catchments for Improving Water Quality using Stream Grouping Method (하천그룹화 방법을 이용한 수질개선 하천유역의 우선순위 선정)

  • Cho, Byungwook;Choi, Jeongho;Yi, Sangjin;Kim, Youngil
    • Journal of Korean Society on Water Environment
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    • v.28 no.1
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    • pp.18-25
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    • 2012
  • For effective watershed management, it is very important to select the tributaries through selection and concentration of targeted tributary catchments for improving water quality within the limited financial conditions. This study introduced the selection and diagnosis procedure of tributary catchments for improving water quality at Chungcheongnam-do based on water quality and flowrate monitoring, stream grouping method. The tributaries with high value of water quality and flowrate were selected for improving water quality according to stream grouping method. The diagnosis of selected tributaries for improving water quality was performed with analysis of the pollution load (generated, discharged, delivered) and point source discharged pollution load density. The plans for improving water quality of tributaries were suggested thorough various diagnosis of tributary catchments. For improving water quality of tributaries in Chungcheongnam-do, the tributary catchments in the Dangjin, Asan, Yesan, Cheonan, Hongseong area should be preferentially considered. The water quality improving plans for those tributary catchments, in accordance with the reduction of sources of pollution by population and livestock, should be established.

Comparative Evaluation of UAV NIR Imagery versusin-situ Point Photo in Surveying Urban Tributary Vegetation (도심소하천 식생조사에서 현장사진과 UAV 근적외선 영상의 비교평가)

  • Lee, Jung-Joo;Hwang, Young-Seok;Park, Seong-Il;Um, Jung-Sup
    • Journal of Environmental Impact Assessment
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    • v.27 no.5
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    • pp.475-488
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    • 2018
  • Surveying urban tributary vegetation is based mainly on field sampling at present. The tributary vegetation survey integrating UAV NIR(Unmanned Aerial Vehicle Near Infrared Radiance) imagery and in-situ point photo has received only limited attentions from the field ecologist. The reason for this could be the largely undemonstrated applicability of UAV NIR imagery by the field ecologist as a monitoring tool for urban tributary vegetation. The principal advantage of UAV NIR imagery as a remote sensor is to provide, in a cost-effective manner, information required for a very narrow swath target such as urban tributary (10m width or so), utilizing very low altitude flight, real-time geo-referencing and stereo imaging. An exhaustive and realistic comparison of the two techniques was conducted, based on operational customer requirement of urban tributary vegetation survey: synoptic information, ground detail and quantitative data collection. UAV NIR imagery made it possible to identify area-wide patterns of the major plant communities subject to many different influences (e.g. artificial land use pattern), which cannot be acquired by traditional field sampling. Although field survey has already gained worldwide recognition by plant ecologists as a typical method of urban tributary vegetation monitoring, this approach did not provide a level of information that is either scientifically reliable or economically feasible in terms of urban tributary vegetation (e.g. remedial field works). It is anticipated that this research output could be used as a valuable reference for area-wide information obtained by UAV NIR imagery in urban tributary vegetation survey.

Numerical Analysis of Flow and Bed Changes due to Tributary Inflow Variation at the Confluence of the Namhan River and the Geumdang Stream (남한강과 금당천 합류부 구간에서의 지류 유입유량 변화에 따른 흐름특성 및 하상변동 수치모의)

  • Ji, Un;Jang, Eun Kyung
    • Journal of Korea Water Resources Association
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    • v.47 no.11
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    • pp.1027-1037
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    • 2014
  • Flow and bed changes due to tributary inflow variation at the confluence of the Namhan River and the Geumdang Stream were analyzed in this study using a two-dimensional numerical model. As a result of the numerical analysis, the velocity downstream of the confluence was greater than the velocity upstream of the confluence in the main channel regardless of the magnitude of tributary inflow. However, as tributary discharge increased, the channel erosion was accelerated and the dry area was produced at the tributary. Due to the bed erosion at the tributary, sediment transport was increased and the eroded sediments were deposited in the confluence area. The deposition in the confluence area changed the flow direction at the main channel to the left side and the localized flow eroded the channel bed at the left side. Therefore, it is expected that bank failure due to continuous bed degradation is possible in this area.

Use of Tributary Water Quality and Flowrate Monitoring Data for Effective Implementation of TMDL (수질오염총량관리제의 효율적인 시행을 위한 지류하천 수질.유량모니터링 자료의 활용)

  • Kim, Young-Il;Jeong, Woo-Hyeok;Kim, Hong-Su;Yi, Sang-Jin
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.2
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    • pp.119-125
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    • 2012
  • The tributary water quality and flowrate monitoring result, which is fundamental data for the establishment of the water environmental policy, is used as very important data for the implementation of TMDL. This study introduced how to use the tributary water quality and flowrate monitoring data for the analysis of the watersheds, the satisfactory assessment of water quality standards in the watersheds, the selection of watersheds for the establishment of the implementation plan, and the selection of the tributary catchments for improving the water quality using a stream grouping method. According to the analytical results of tributary catchment using water quality and flowrate monitoring data of thirty-seven tributaries in the Geum-River watershed at Chungcheongnam-do, the value of flowrate in the tributaries, which is located in the middle-lower Geum-River watershed, was greater than the other areas and the concentration of the water pollutants regardless of water quality parameters in the tributaries at Nonsancheon catchment was relatively higher than the other areas. The problems, which have the determination of satisfaction of water quality standards and selection of target watersheds for establishment of the implementation plan regardless of the water quality of tributary in the watershed due to the water quality and flowrate monitoring results of the main river, were improved use of the results of tributary water quality and flowrate monitoring. Also, the tributary catchments for improving the water quality, according to stream grouping method based on the results of tributary water quality and flowrate monitoring, were selected. In the Geum-River watershed at Chungcheongnam-do, the tributary in the Nonsancheon, Byeongcheoncheon, Seokseongcheon, Jocheon catchments, which has a large flow and a high concentration of water pollutants, should be preferentially selected for improving the water quality of the tributary in accordance with the reduction of the source of pollution.

Water quality of an Indian tributary affected by various industrial effluents- a case study

  • Bharti, Bharti;Jangwan, J.S.;Kumar, Amrish;Kumar, Vivek
    • Advances in environmental research
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    • v.9 no.1
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    • pp.41-54
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    • 2020
  • Industrialization and urbanization are modern need and trends. Such trends affect the natural ecosystem of rivers. Indian rivers face such problems in a high ratio. The aim of this study is to investigate the cause and amount of pollution in a tributary river Krishni. Pre-monsoon sampling of Krishni river water was performed as per APHA standard. Water samples were collected from different sites of Krishni river. Physiochemical parameters as well as trace elements concentrations have been analysed and results were compared with BIS-2012, WHO-2017 and EPA-2001 recommendations. The presence of high BOD, COD, TDS and others physiochemical parameters along with heavy metals reveals that tributary is highly polluted owing to industrial and domestic discharge either directly or through drains. High values of these parameters are harmful for the ecological health of the river because it makes survival of aquatic flora and fauna at risk. On the basis of the results obtained by the present study, it was concluded that level of the pollution in river Krishni is at alarming phase, where if strong action for the rejuvenation of river not takes place, river becomes a dead pool.

Analysis of Functional Habitat Groups of Benthic Macroinvertebrates according to Changes in the Riverbed (하상 변화에 따른 저서성 대형무척추동물의 서식기능군 분석)

  • Lee, Seul Hee;Lee, Mi Jin;Seo, Eul Won;Lee, Jong Eun
    • Journal of Environmental Science International
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    • v.26 no.3
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    • pp.373-380
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    • 2017
  • This study identified the effect of changes in the riverbed on the benthic macroinvertebrate communities. The benthic macroinvertebrates collected from the surveyed sites belonged to 119 species, 65 families, 20 orders, and 7 classes in 4 phyla. The number of Ephemeroptera, Plecoptera, and Trichoptera (E.P.T) species was 42, 10, and 8, respectively, in the tributary, confluence, and Nakdong River sites. Lotic species (Hydropsychidae) showed a high density at the tributary sites, whereas lentic species (Chironomidae) showed a high density at the confluence and Nakdong River sites. Community analysis showed that the Dominance Index (DI) was 0.54 in tributary sites, and dominance indices increased closer to the Nakdong River sites. The diversity index (H') was inversely proportional to DI. The ratio of Burrowers species (BU) at the surveyed sites increased closer to the Nakdong River sites. Analysis of common species showed 37 species (34.6%) between the tributary and confluence sites and 66 species (51.5%) between the confluence and Nakdong River sites.

Selection of Priority Management Target Tributary for Effective Watershed Management in Nam-River Mid-watershed (남강 중권역의 효율적인 유역관리를 위한 중점관리 대상지류 선정)

  • Jung, Kang-Young;Kim, Gyeong-Hoon;Lee, Jae-Woon;Lee, In Jung;Yoon, Jong-Su;Lee, Kyung-Lak;Im, Tae-Hyo
    • Journal of Korean Society on Water Environment
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    • v.29 no.4
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    • pp.514-522
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    • 2013
  • The major 24 tributaries in Nam-River mid-watershed were monitored for discharge and water quality in order to understand the characteristics of the watershed and to select the tributary catchment for improving water quality. According to the analytical results of discharge and water quality monitoring data of 24 tributaries, the mean value of discharge below $0.1m^3/s$ was 62.5% among the monitored tributaries and it mostly exceeded the water quality standards of Nam-river mid-watershed ($BOD_5$ = 3 mg/L, T-P = 0.1 mg/L over). According to the stream grouping method and the water quality delivery load density ($kg/day/km^2$) based on the results of tributary discharge and water quality monitoring, the tributary watersheds for improving the water quality were selected. In the Nam-River mid-watershed, tributaries in the GaJwaCheon, HaChonCheon catchment (Group D, $BOD_5$ = 3 mg/L over) and in the UirYeongCheon, SeokGyoCheon catchment (Group A, T-P = 0.1 mg/L over), which have a small flow (and/or large flow) and a high concentrations of water pollutants. The various water quality improving scheme for tributaries, in accordance with the reduction of potential point source pollution by living sewage and livestock wastewater, should be established and implemented.

Investigating of Nitrosamines in Small tributary rivers, Sewage Tretment Plants and Drinking Water Treatment Plants (하천수 및 상하수도처리공정에서의 니트로사민류 조사)

  • Kim, Gyunga;Roh, Jaesoon;Bin, Jaehun;Kim, Changwon
    • Journal of Korean Society on Water Environment
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    • v.26 no.3
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    • pp.446-453
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    • 2010
  • This study was investigated nine nitrosamines in small tributary rivers, sewage treatment plants (STPs) and drinking water treatment plants. They are N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), N-nitrosodi-n-propylamine (NDPA), N-nitrosomorpholine (NMOR), N-nitrosopiperidine (NPIP), N-nitrosodi-n-butylamine (NDBA) and N-nitrosodiphenylamine (NDPHA). The nine nitrosamines were analyzed by gas chromatography mass spectrometry (GC/MS) using solid phase extraction (SPE) with a coconut charcoal cartridge. Among the nine nitrosamines, NDMA, NMEA, NDEA, NDPA NDBA and NDPHA were detected in small tributary rivers and sewage tretment plants. In small tributary rivers, NDMA, NMEA, NDEA, NDPA, NDBA and NDPHA were obtained as ND~16.4 ng/L, ND~17.7 ng/L, ND~102.4 ng/L, ND~455.4 ng/L, ND~330.1 ng/L and ND~161.0 ng/L, respectively. Also NDMA, NMEA, NDEA, NDPA and NDBA were investigated ND~821.4 ng/L, 22.5~55.4 ng/L, 53.2~588.5 ng/L, ND~56.6 ng/L and ND~527.9 ng/L in STPs, respectively. In drinking water treatment plants, NMEA and NDEA concentration were increased to as high as 38.8 ng/L after ozonation process. However nitrosamines were decreased subsequent biological activated carbon (BAC) treatment process. It was supposed that nitrosamines were formed by $O_3$ oxidation and were removed by biodegradation of BAC.

Fluctuating wind loads across gable-end buildings with planar and curved roofs

  • Ginger, J.D.
    • Wind and Structures
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    • v.7 no.6
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    • pp.359-372
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    • 2004
  • Wind tunnel model studies were carried out to determine the wind load distribution on tributary areas near the gable-end of large, low-rise buildings with high pitch planar and curved roof shapes. Background pressure fluctuations on each tributary area are described by a series of uncorrelated modes given by the eigenvectors of the force covariance matrix. Analysis of eigenvalues shows that the dominant first mode contributes around 40% to the fluctuating pressures, and the eigenvector mode-shape generally follows the mean pressure distribution. The first mode contributes significantly to the fluctuating load effect, when its influence line is similar to the mode-shape. For such cases, the effective static pressure distribution closely follows the mean pressure distribution on the tributary area, and the quasi-static method would provide a good estimate of peak load effects.