• Title, Summary, Keyword: Sediment cell

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Development and Evaluation of SWAT Topographic Feature Extraction Error(STOPFEE) Fix Module from Low Resolution DEM (저해상도 DEM 사용으로 인한 SWAT 지형 인자 추출 오류 개선 모듈 개발 및 평가)

  • Kim, Jong-gun;Park, Youn-shik;Kim, Nam-won;Chung, Il-moon;Jang, Won-seok;Park, Jun-ho;Moon, Jong-pil;Lim, Kyoung Jae
    • Journal of Korean Society on Water Environment
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    • v.24 no.4
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    • pp.488-498
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    • 2008
  • Soil and Water Assessment Tool (SWAT) model have been widely used in simulating hydrology and water quality analysis at watershed scale. The SWAT model extracts topographic feature using the Digital Elevation Model (DEM) for hydrology and pollutant generation and transportation within watershed. Use of various DEM cell size in the SWAT leads to different results in extracting topographic feature for each subwatershed. So, it is recommended that model users use very detailed spatial resolution DEM for accurate hydrology analysis and water quality simulation. However, use of high resolution DEM is sometimes difficult to obtain and not efficient because of computer processing capacity and model execution time. Thus, the SWAT Topographic Feature Extraction Error (STOPFEE) Fix module, which can extract topographic feature of high resolution DEM from low resolution and updates SWAT topographic feature automatically, was developed and evaluated in this study. The analysis of average slope vs. DEM cell size revealed that average slope of watershed increases with decrease in DEM cell size, finer resolution of DEM. This falsification of topographic feature with low resolution DEM affects soil erosion and sediment behaviors in the watershed. The annual average sediment for Soyanggang-dam watershed with DEM cell size of 20 m was compared with DEM cell size of 100 m. There was 83.8% difference in simulated sediment without STOPFEE module and 4.4% difference with STOPFEE module applied although the same model input data were used in SWAT run. For Imha-dam watershed, there was 43.4% differences without STOPFEE module and 0.3% difference with STOPFEE module. Thus, the STOPFEE topographic database for Soyanggang-dam watershed was applied for Chungju-dam watershed because its topographic features are similar to Soyanggang-dam watershed. Without the STOPFEE module, there was 98.7% difference in simulated sediment for Chungju-dam watershed for DEM cell size of both 20 m and 100 m. However there was 20.7% difference in simulated sediment with STOPFEE topographic database for Soyanggang-dam watershed. The application results of STOPFEE for three watersheds showed that the STOPFEE module developed in this study is an effective tool to extract topographic feature of high resolution DEM from low resolution DEM. With the STOPFEE module, low-capacity computer can be also used for accurate hydrology and sediment modeling for bigger size watershed with the SWAT. It is deemed that the STOPFEE module database needs to be extended for various watersheds in Korea for wide application and accurate SWAT runs with lower resolution DEM.

Evaluation of the Applicability of Sediment Discharge Measurement in Mountain Stream using the Load-cell Sensor (Load-cell Sensor를 이용한 산지 토사유출량 계측의 현장 적용성 검토)

  • Seo, Jun-Pyo;Lee, Ki-Hwan;Kim, Dong-Yeob;Woo, Choong-Shik;Lee, Chang-Woo;Lee, Heon-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.644-653
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    • 2018
  • Landslides occur frequently due to the effects of heavy rainfall and typhoons caused by climate change. Erosion control measures are needed to effectively prevent landslide damage. In order to improve their efficiency, it is necessary to quantitatively measure the sediment discharge from the mountain stream. In this study, a load cell sensor was installed in a mountain stream and the measured values were compared according to the applicability and load test type in the mountain stream. The result of the load test showed that the effect of the loading type (load test 1, 2) was low at average (loadings) of 0.4kgf and 0.6kgf at sites 1 and 2, respectively. The load factor was also derived by regression analysis to increase the accuracy of the measured values. According to the results of the load factor (normalized) to the load-cell measurement value, the output value increased by 14.8% and 24.6% in sites 1 and 2, respectively, and was calculated to be similar to the reference value. The load cell sensor enabled us to quantitatively estimate the amount of sediment discharge in the mountain stream through time series analysis with the water level and rainfall information. If the monitoring is carried out for a long time, it can be used to find the sediment discharge mechanism for the mountain stream. In addition, applying sensors such as load-cells to a mountain stream is expected to contribute to the development of related industries, such as the manufacturing of measurement sensors.

Performances of Metallic (sole, composite) and Non-Metallic Anodes to Harness Power in Sediment Microbial Fuel Cells

  • Haque, Niamul;Cho, Daechul;Kwon, Sunghyun
    • Environmental Engineering Research
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    • v.19 no.4
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    • pp.363-367
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    • 2014
  • One chambered sediment microbial fuel cell (SMFC) was equipped with Fe, brass (Cu/Zn), Fe/Zn, Cu, Cu/carbon cloth and graphite felt anode. Graphite felt was used as common cathode. The SMFC was membrane-less and mediator-less as well. Order of anodic performance on the basis of power density was Fe/Zn ($6.90Wm^{-2}$) > Fe ($6.03Wm^{-2}$) > Cu/carbon cloth ($2.13Wm^{-2}$) > Cu ($1.13Wm^{-2}$) > brass ($Cu/Zn=0.24Wm^{-2}$) > graphite felt ($0.10Wm^{-2}$). Fe/Zn composite anode have twisted 6.73% more power than Fe alone, Cu/carbon cloth boosted power production by 65%, and brass (Cu/Zn) produced 65% less power than Cu alone. Graphite felt have shown the lowest electricity generation because of its poor galvanic potential. The estuarine sediment served as supplier of oxidants or electron producing microbial flora, which evoked electrons via a complicated direct microbial electron transfer mechanism or making biofilm, respectively. Oxidation reduction was kept to be stationary over time except at the very initial period (mostly for sediment positioning) at anodes. Based on these findings, cost effective and efficient anodic material can be suggested for better SMFC configurations and stimulate towards practical value and application.

Removal of Cochlodinium polykrikoides using a novel material produced from sediment - A field study

  • Song, Young-Chae;Sivakumar, S.;Ko, Sung-Chung;Hwang, Eung-Ju;Jo, Q-Tae
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.200-201
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    • 2007
  • The present study was conducted in three fields at Namhae to examine the removal efficiency of organic free, heavy metal immobilized sediment on Cochlodinium polykrikoidesand and on sea water quality. The present study results concluded that removal efficiency was depends on the initial number of red tide cells. There was no drastic change in the sea water quality after sediment spray. For the comparison of effectiveness of betonite, zeolite and lime were mixed with sediment did not show any marked difference in removal. Finally, the present study evaluated 50g/$m^{2}$ sediment is sufficient to remove 100% cells density, even though various environmental factors are interfering the mechanism.

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Comparison of the effects of physico-chemical factors on the zonation and vertical distribution of benthic microalgal communities in the tidal flats of south-west Korea (한국 남서부 갯벌의 저서성 미세조류의 대상분포와 수직분포에 미치는 이화학적 요인의 효과에 관한 비교)

  • 이학영
    • Journal of Environmental Science International
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    • v.11 no.6
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    • pp.529-535
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    • 2002
  • Efffcts of physico-chemical factors on the zonation and vertical distribution of benthic microalgal communities in the tidal flats of Youngkwang and Canaiin, Korea, were studied. Concentrations of nutrients were low throughout the study period. A 38 species of benthic microaigae was identified. Most of the algae were pennate diatoms with small size. Cell numbers at silty sediments were higher than sandy sediments, and showed high patchy distribution. Zonal distributions of benthic microalgae showed higher variation from silty sediment than sandy sediments. Benthic microalgae showed vertical migration within the upper few mm of sediment with periodicity closely related to tidal cycles. Maximum cells were observed from 0 mm depth both sandy and silty sediments. Cells of benthic microalgae in the 1 - 2 mm depth decreased after desiccation of sediments. The variation of cells was higher at sandy sediments than silty sediments. Cell numbers of benthic microalgae showed no positive relationships with pH and nutrinets except NH$_4$-N.

Cyanobacteria Community and Growth Potential Test in Sediment of Lake Paldang (팔당호 퇴적층 남조류의 군집과 남조류 성장잠재성 분석)

  • Kim, Yong-Jin;Baek, Jun-Soo;Youn, Seok-Jea;Kim, Hun-Nyun;Lee, Byoung-cheun;Kim, Gueeda;Park, Songeun;You, Kyung A;Lee, Jae-Kwan
    • Journal of Korean Society on Water Environment
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    • v.32 no.3
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    • pp.261-270
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    • 2016
  • We analyzed cyanobacterial community including akinete, resting cell, and benthic cyanobacteria in sediment of Bukhan, Namhan-River, Paldang-Lake, and Kyeongan-Stream and compared the physicochemical factors for water and pore water. We also performed cyanobacteria growth potential test through incubating sediment. As a result of physicochemical analysis, the concentrations of nutrients were similar for each depth of Bukhan-River. For Namhan-River and Lake Paldang sites, the concentrations of TP and DTN in bottom and deep water had higher levels. DTN in water body composed of NO3-N(73%) while DTN in pore water composed of NH3-N(77.8%). Benthic cyanobacteria in the sediment such as Oscillatoria tenuis, O. limosa, Phormidium tenue, Pseudanabaena limnetica, and Lyngbya sp. were dominant (between 0.0∼243.3×103 cells/g, w/w). Cell densities of cyanobacteria in sediment depth of 0∼2 cm in most sites were higher compared to those in other depths. The cell density of cyanobacteria in sediment correlated with pH, conductivity, BOD5, TP, DTP, and chl. a. Increased phytoplankton and organic matters were found to be able to inhibit the growth of benthic cyanobacteria. Results of cyanobacteria growth potential test after incubating sediment revealed that harmful cyanobacteria (Anabaena, Aphanizomenon, Microcystis, and Oscillatoria) appeared at 7 days post culturing. Base on these results, the methods used in this study are considered to be able to determine the appearance of harmful cyanobacteria.

Distribution of Electrochemically Active Bacteria in the Sediment (Sediment에서의 전기활성 박테리아 분포 특성)

  • Son, Hyeng-Sik;Son, Hee-Jong;Kim, Mi-A;Lee, Sang-Joon
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.12
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    • pp.1094-1101
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    • 2010
  • Microbial fuel cells (MFC) were enriched using sediment Nakdong river, Hoidong river and protected water area in Gijang. The microbial community of sediment and enriched MFC was analyzed by FISH (fluorescent in situ hybridization) and 16S rDNA sequencing. ${\alpha}$-Proteobacteria, Acidobacter and Cyanobactia group were dominant in sediment by FISH. The coulombs of the final 10 peak of the 3 MFC (Nakdong, Hoidong, Gijang) were 0.64 C, 0.50 C, 0.61 C, respectively. When MFCs were enriched by sediment, ${\beta}$-, ${\gamma}$-Proteobacteria, Acidobacter and Firmicutes group increased 45~90%, 50~90%, 40~80% and 45~125%, respectively. In results of 16S rDNA sequencing, Roseomonas sp., Azospillium sp., Frateuria sp., Dyella sp., Enterobacter sp. and Deinocossus were isolated from Nakdong river and Azospillium sp., Delftia sp., Ralstonia sp., Klebsiella sp. and Deinococcus sp. were isolated from protected water area in Gijang and Pseudomonas sp., Klebsiella sp., Deinococcus sp., Leifsonia sp. and Bacillus sp. were isolated from Hoidong river.

The Characteristics and Experimental Application of AGNPS Model for Pollution Predicting in Small Watershed (소유역 오염예측모형 AGNPS 의 특성과 실험적 적용)

  • Choi, Jin-Kyu;Lee, Myung-Woo;Son, Jae-Gwon
    • Journal of Environmental Impact Assessment
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    • v.3 no.2
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    • pp.47-56
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    • 1994
  • AGNPS model is an event-based model to analyze nonpoint-source and to examine potential water quality problems from agricultural watershed. This model uses a square grid-cell system to represent the spatial variability of watershed conditions, and simulates runoff, sediment, and nutrient transport for each cell. AGNPS model was applied on Yeonwha watershed, and the test results were compared with the measured data for runoff volume, peak runoff rate, suspended solids, and phosphorus concentration. The watershed of 278.8 ha was divided into 278 cells, each of which was 1 ha in size. The coefficients of determination for runoff volume and peak flow were (0.893 and 0.801 respectively from regression of the estimated values on the measured values. The concentration of suspendid solid was increased but decreased that of phosphate with runoff volume.

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The Analysis of Optimum Resolution with Different Scale of Soil Map for the Calculation of Soil Loss (토양침식량 산정에서 토양도 축척에 따른 적정 해상도 분석에 관한 연구)

  • Lee, Greun-Sang;Jang, Young-Ryul;Cho, Gi-Sung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.6 no.3
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    • pp.1-10
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    • 2003
  • RUSLE(revised universal soil loss equation) has been widely used for estimating soil loss. It is very difficult to validate the model estimation since the calculated soil loss should be compared with the survey data for quantification. The input variables for RUSLE model were estimated to grid cell for raster analysis in Bosung basin. Both reconnaissance(1:250,000) and detailed(1:25,000) soil maps were used to derive the input variables for soil erodibility factor. Soil loss calculated using RUSLE were compared to the unit sediment deposit surveyed by KICT(Korea Institute of Construction Technology, 1992) in Bosung basin for assessment. Unit sediment deposit from the cell size of 120m and 150m were the closest to the survey data in 1:250,000 and 1:25,000 map scale, respectively.

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