• Title/Summary/Keyword: sediment information

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Assessment of Sediment Yield according to Observed Dataset

  • Lee, Sangeun;Kang, Sanghyeok
    • Journal of Environmental Science International
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    • v.25 no.10
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    • pp.1433-1444
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    • 2016
  • South Korea is a maritime nation, surrounded by water on three sides; hence, it is important to preserve in a sustainable manner. Most areas, especially those bordering the East Sea, have been suffering from severe coastal erosion. Information on the sediment yield of a river basin is an important requirement for water resources development and management. In Korea, data on suspended sediment yield are limited owing to a lack of logistic support for systematic sediment sampling activities. This paper presents an integrated approach to estimate the sediment yield for ungauged coastal basins by using a soil erosion model and a sediment delivery rate model in a geographic information system (GIS)-based platform. For applying the sediment yield model, a basin specific parameter was validated on the basis of field data, that, ranging from 0.6 to 1.2 for the 19 gauging stations. The calculated specific sediment yield ranged from 17 to $181t/km^2.yr$ in the various basin sizes of Korea. We obtained reasonable sediment yield values when comparing the measured data trends around the world with those in Korean basins.

Prediction of total sediment load: A case study of Wadi Arbaat in eastern Sudan

  • Aldrees, Ali;Bakheit, Abubakr Taha;Assilzadeh, Hamid
    • Smart Structures and Systems
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    • v.26 no.6
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    • pp.781-796
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    • 2020
  • Prediction of total sediment load is essential in an extensive range of problems such as the design of the dead volume of dams, design of stable channels, sediment transport in the rivers, calculation of bridge piers degradation, prediction of sand and gravel mining effects on river-bed equilibrium, determination of the environmental impacts and dredging necessities. This paper is aimed to investigate and predict the total sediment load of the Wadi Arbaat in Eastern Sudan. The study was estimated the sediment load by separate total sediment load into bedload and Suspended Load (SL), independently. Although the sediment records are not sufficient to construct the discharge-sediment yield relationship and Sediment Rating Curve (SRC), the total sediment loads were predicted based on the discharge and Suspended Sediment Concentration (SSC). The turbidity data NTU in water quality has been used for prediction of the SSC in the estimation of suspended Sediment Yield (SY) transport of Wadi Arbaat. The sediment curves can be used for the estimation of the suspended SYs from the watershed area. The amount of information available for Khor Arbaat case study on sediment is poor data. However, the total sediment load is essential for the optimal control of the sediment transport on Khor Arbaat sediment and the protection of the dams on the upper gate area. The results show that the proposed model is found to be considered adequate to predict the total sediment load.

An Efficient Method Of The Suspended Sediment-Discharge Measurement Using Entropy Concept

  • Choo, Tai-Ho
    • Water Engineering Research
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    • v.1 no.2
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    • pp.95-105
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    • 2000
  • A method is presented which enables easily the computation of the suspended sediment discharge as the mean sediment concentration and mean flow velocity. This method has significant advantages over the traditional method, which principally depend on a set of measured concentration data. The method is based on both a new sediment concentration and mean sediment concentration equations which have been derived from the entropy concept used in statistical mechanics and information theory: (1) The sediment concentration distribution equations derived, are capable of describing the variation of the concentration in the vertical direction. (2) The mean concentration equation derived, is capable of calculating easily the mean concentration by using only one measured concentration in open channel. The present study mainly addresses the following two subjects : (1) new sediment concentration and mean sediment concentration equations are derived from the entropy concept : (2) An efficient and useful method of suspended sediment-discharge measurements is developed which can facilitate the estimation of suspended sediment-discharge in open channel. Flume and laboratory data are used to carry out the research task outlined above. An efficient method for determining the suspended sediment-discharge in the open channel has been developed. The method presented also is efficient and applicable in estimating the sediment transport in rivers and the sediment deposit in the reservoirs, and can drastically reduce the time and cost of sediment measurements.

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The Effects of Hydrologic Characteristics on Sediment Discharge in Streams with Small and Medium Size Watersheds (중소유역의 수문학적 특성이 하천유사량에 미치는 영향)

  • 김활곤;서승덕
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.38 no.3
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    • pp.127-136
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    • 1996
  • The purpose of this study is to provide with information for the water resources development and management in stream management planning, such as information on the sediment trensport, design of dam and water facilities, river improvement and flood plains management. The major results obtained from the field measurement and analysis of the watershed characteristics, hydraulic and sediment characteristics are as follows ; 1. The rating curve formulas obtained from the analysis of the hydraulic characteristics data collected are ; Q-=110.563 $(H-0.474)^2$ for 0.7m$(H-0.146)^2$ for 0.4m$Sr=aX{^2} {_1} X^{c}{_2}$, in the experimental watershed.

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Parcel based Information System for Sediment Disaster by using Mobile GIS (모바일 GIS를 이용한 필지별 토사재해정보시스템 개발)

  • Lee, Geun-Sang;Choi, Yun-Woong
    • Journal of Cadastre & Land InformatiX
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    • v.46 no.1
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    • pp.59-74
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    • 2016
  • The collapses of retaining walls or embankments, the soil erosion and landslides around urban areas are occurring by heavy rainfalls because of the recent climate change. This study conducts the soil erosion modeling, while applying the spatial information such as soil maps, DEM and landcover maps to the RUSLE model. Especially this study draws up the soil erosion grade map and the unit soil erosion grade map by parcels through coupling the soil erosion with the cadastral map, and by that can calculate the number of parcels by soil erosion grades. Also the sediment disaster information system based on the mobile GIS is developed to identify the soil erosion grades of site in the urban plannings and the construction fields. The sediment disaster information system can identify the present conditions of the registers of lands, buildings and roads, and confirm the RUSLE factors, the soil erosion, the sediment disaster grades by parcels. Also it is anticipated that this system can support the sediment disaster work of site effectively through searching the locations and attributes of the specific parcels by Administrative Dong and the soil erosion grades.

Time-series Changes in Particle Size Characteristics of Suspended Sediment at the Seungchon and the Juksan Weir in the Yeongsan River (영산강 부유하중의 시계열적 입도 특성 변화: 승촌보, 죽산보를 중심으로)

  • Lim, Young Shin;Kim, Jin Kwan
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.4
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    • pp.1-20
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    • 2019
  • In order to establish appropriate policy to control sediment-associated problems, it is necessary to identify the physical characteristics of the reservoir sediments in particulate form in the Yeongsan River. Two time-integrated suspended sediment samplers were installed at Seungchon and Juksan weir on the upper and middle Yeongsan River in July 2012. Reservoir sediment samples were obtained at monthly intervals until October 2014. During the monitoring period, a total of 38 sediment samples were obtained and analyzed. Seasonal trends of suspended sedimentation rates and grain size distributions were examined based on variations in precipitation and discharge fluctuations. Moreover, stream flow characteristics, which has a great influence on the physical characteristics of the river sediment, was analyzed using flow duration curve for the period 2003-2019 at Naju gauging station. Sedimentation rates during summer, when heavy rainfall was concentrated due to the monsoonal front and typhoon, were very high, indicating the positive relationship between sediment concentration and discharge. Particle size analysis of the collected sediment showed that coarse silt and very fine sand-sized sediment dominated most of the Seungchon weir sediment. On the other hand, medium silt-sized sediment dominated the downstream Juksan weir except for a few summer samples. These results implied that the physical characteristics of the suspended sediment are determined not only due to flow fluctuations, but also with regard to the antecedent rainfall conditions, hillslope-channel connectivity, and the supply of materials from various contributing regions. This information about flow characteristics and temporal variations in reservoir sediment can be used for safe management of the weir and discussing the issues on the dismantling of the weirs.

Simulation of Sediment Deposition Behavior in a Reservoir using a SED2D model: Focusing on Sensitivity of Simulation Time Step (SED2D모형을 이용한 저수지 퇴사거동 모의-모의시간간격의 민감도를 중심으로)

  • Kim, Dae Guen
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.1
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    • pp.87-95
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    • 2012
  • In this study, the following conclusions were obtained from an investigation of the effect of the simulation time step on the simulation results of the two-dimensional, vertically averaged sediment transport model SED2D and an analysis of the deposited sediment distribution in suspended sediments of reservoirs according to grain size. The simulation time step has a significant effect on the deposited sediment distribution in a reservoir. In particular, if the simulation time step is set to be excessively large, physically invalid results are obtained. Additionally, in order to determine an appropriate simulation time step for SED2D, the selection of a simulation time step that will allow the analysis of the suspended sediment concentration profile at the main points of the simulation domain is necessary. The deposited sediment distribution in a reservoir according to grain size, including suspended sediments of clay, silt, and sand, was successfully simulated. Such information will prove valuable in application to the establishment of efficient management and reduction measures of reservoir sediment deposits.

Application of a Sediment Quality Index to the Masan Bay, Korea

  • Shim, Won-Joon;Hong, Sang-Hee
    • Ocean and Polar Research
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    • v.29 no.4
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    • pp.367-378
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    • 2007
  • A sediment quality index (SQI) and a mean sediment quality guideline quotient (M-SQGQ) were applied for the assessment of sediment quality in Masan Bay, Korea where metals and organic pollutants are of concern. The SQI was calculated by two functions, 'scope' (the number of variables that do not meet guideline objective) and 'amplitude' (the magnitude by which variables exceed guideline objective), with six different sediment quality guideline values from Canada, USA and Australia/New Zealand. Categorization of sediment quality was on the basis of SQI scores. The SQI values were compared with six guideline values applied as well as with the M-SQGQs. The SQI values were severely influenced by a few variables of high exceedance in the degree of non-compliance. The SQI values were very dependent on both the numbers and values of guideline variables used in index caluculation. Nevertheless, the SQI could provide integrated and simplified information from a large number of chemical data set. It is required to further evaluate protocols and guideline applied for deriving SQI and to compare it with field based sediment toxicity test and ecosystem integrity.

The Suspended Sediment Change Detection of Imha Dam Using Multi-Temporal Satellite Data (다중시기 위성영상을 이용한 임하댐 부유사 변화탐지)

  • Jeong, Jong-Chul
    • Spatial Information Research
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    • v.15 no.1
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    • pp.25-33
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    • 2007
  • The purpose of this study is to assess spatio-temporal variation of Imha Dam water quality according to suspended sediment algorithm using Landsat and SPOT 5 data. In order to learn synchronous suspended sediment concentrations(SSC) in Imha Dam waters, the satellite remote sensing data are analyzed. The key procedure of this research is that we should know the relationships between suspended sediment concentrations and satellite-detected reflectance. However, the SSC algorithm has the limitation that it must be compared calculated SSC with synchronous ground-truth data in the Dam water. Based upon the linear response from satellite-detected reflectance, SSC algorithm validated an efficient algorithm to estimate proportional factor and then derived an empirical equation far SSC estimations.

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Analyzing the Effectiveness of a Best Management Practice on Sediment Yields Using a Spatially Distributed Model (공간분포형 모델을 이용한 최적관리방안의 토사 유출 저감 효과에 관한 연구)

  • Lee, Taesoo
    • Journal of the Korean Geographical Society
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    • v.52 no.1
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    • pp.15-24
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    • 2017
  • Management of non-point sources for water quality control practice is complicating but very important. Sediments mainly from croplands are prioritized in non-point source management due to the sediment attached phosphorous. In this study, flow and sediment yields are modeled in Oenam watershed located in Hwasun, Jeollanam-do, a upstream of Juam Lake. A spatially distributed model and GIS(Geographic Information System) data was used to find out hot spots of sediment yields, to analyze the effectiveness of filter strips, and to visualize the effectiveness. The impacts of filter strips was estimated on the reduction of flow and sediments at 17.2% and 46.4% respectively when the filter strips were installed in the sub-watersheds with the most serious sediment yields.

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