• 지역사회간호학회지
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• 제21권2호
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• pp.242-251
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• 2010

Purpose: This study investigated the factors of C. sinensis infection among the residents in vicinity of the Nakdong River and the infection status of fishes in the stream with C. sinensis maetacercaria. Methods: Selected five regions of the Nakdong River and collected freshwater fishes from the stream to examine their metacercarial infections; and studied the status and causes of C. sinensis infection in 552 residents living within 5 kilometers from the river. Results: Among the 552 residents studied, 13.8% were infected with C. sinensis, and among 379 freshwater fishes of 20 species collected from the five regions, 41 fishes of 8 species were infected with C. sinensis metacercaria. Conclusion: In order to prevent human C. sinensis infection and transition to chronic liver ions, we need to develop and apply good programs such as continuous health education, personal hygiene improvement, active medical treatment for those infected with C. sinensis, and residents’ voluntarily stop of eating freshwater fishes in the raw state.

• The Korean Journal of Ecology
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• 제22권6호
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• pp.337-342
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• 1999

Rotifer grazing rates in both species and community levels on bacteria and phytoplankton were determined by using representative models (fluorescent beads: 0.75$\mu m$ for bacteria and 10 $\mu m$ for phytoplankton) at biweekly intervals. One-year study at the lower part of the Nakdong River (Mulgum) indicated that the seasonal pattern of rotifer biomass was similar to that of total zooplankton biomass. Total mean biomass of rotifers was significantly higher than that of other groups (rotifers, 148$\pm $327 $\mu g$C/l; cladoceran. 25$\pm 69$$\mu g$C/l; copepodids. 58$\pm 159$$\mu g$C/l). For laboratory grazing experiments. mean specific filtering rate (SFR: $ml\cdot \; l^{-1}\cdot \; day^{-1}$) for rotifers varied from 0.001 to 0.726, and > 90% individuals of rotifer species took up fluorescent microspheres. The high SFRs were achieved by Brachionus angularis, B. calyciflorus, and Filinia longiseta. Community filtering rates (CFRs, $ml\cdot \; l^{-1}\cdot \; day^{-1}$) varied in the range from 2 ~ 1,670. Rotifer filtering rates on phytoplankton were much higher than bacterial filtering rates, especially in the late growing season (May. June, and November). Rotifers appear to be important in transferring both bacterial and phytoplankton carbon to higher trophic levels at the lower Nakdong River.

• 한국농공학회논문집
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• 제57권6호
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• pp.153-162
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• 2015

In this study, we analyzed the trends of water quality along the main stream in Nakdong river basin using the recent data and seasonal Mann-Kendall test. Monthly averaged values of DO, BOD, SS, COD, TN, and TP from 1989 to 2014 for 14 stations (including 2 TMDLs stations) were used in the study. The trend analysis results showed that BOD and TP at most stations has decreasing temporal trend except a few stations while COD and SS showed increasing trend at most stations. Temporal trends in TN at 8 stations were found to be statistically significant and 5 of them showed increasing temporal trend. Temporally averaged BOD, COD, TN and TP were generally increasing as going downstream and the worst water quality were found at Goryeong and Hyunpung station. Overall, water quality of Nakdong river especially in COD, SS, and TN getting worse in time at most stations and as going downstream.

• 한국농공학회논문집
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• 제54권3호
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• pp.103-111
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• 2012

Works for dam heightening plan have dual purposes: flood disaster prevention by securing additional storage volume and river ecosystem conservation by supplying stream maintenance flow. Now, the dam heightening project is in progress and there are 93 dam heightened reservoir. After the dam heightening project, 2.2 hundred million ton of flood control volume in reservoirs will be secured. Thus it is necessary to evaluate the effects of the dam heightening project on watershed hydrology and stream hydraulics, and resulting flood damages. This study was aimed to assess the impact of outflow from the dam heightened reservoir group on the Whangryong river design flood. The HEC-HMS (Hydrologic Engineering Center-Hydrologic Modeling System) model was used for estimating flood discharge, while HEC-5 (Hydrologic Engineering Center-5) was used for reservoir routing. This study analysed flood reduction effect on 100yr and 200yr return periods about the before and after heightening of agricultural dams. Based on the results of this study, the reduction of flood peak discharge at downstream of the reservoir group was estimated to be about 41% and 53% for 100yr and 200yr frequencies, respectively.

• 한국산학기술학회논문지
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• 제8권1호
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• pp.130-135
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• 2007

국내 수질의 부식성을 파악하기 위해 RTW 모델과 LPLWIN 모델을 이용하여 탄산칼슘포화지수를 포함한 다양한 지수를 산정하는 절차를 연구하였다. RTW 모델을 이용하여 LI, RI, AI 를 산정할 수 있었고, LPLWIN 모델을 이용하여 LI, LR, CCPP를 산정하였다. 한강 수계와 낙동강 수계를 취수원으로 하는 수돗물 자료를 적용하여 지수값에 근거하여 부식성 여부를 판단하였다. 산정결과에 의하면, 낙동강 수계는 한강수계보다 부식성이 양호한 수질인 것으로 나타났다. 겨울철이 여름철에 비하여 부식성이 큰 것으로 나타나, 온도가 증가할수록 부식성은 감소하는 것으로 조사되었다.

• 한국지형학회지
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• 제23권1호
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• pp.61-75
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• 2016

This study aims to reconstruct sea level change and paleogeomorphology since the middle Holocene by diatom analysis and 14C-dating from the sedimentary facies of three trenches on alluvial plain of Taehwa River, Taehwa-dong, Ulsan-si, South Korea. The Taewha-dong area was a narrow bay located between Bangeojin and eatuary of Taehwa River was a narrow bay which has been detached from the open sea during middle Holocene. Taewa-dong area at bay area was developed into alluvial plain by the sediments had been come from the Taewa river basin. The sea level change during the middle Holocene effected on the development of Taewha-dong alluvial plain and its information is included in the sediment facies.

• 대한토목학회논문집
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• 제38권6호
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• pp.819-829
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• 2018

한강 하구 신곡수중보 하류에서 하상변동 조사를 실시하고 평균 하상고와 하상변동량을 계산하여 하상변동 경향에 대해 검토하였다. 저수로 하상변화에 초점을 맞추기 위해 부등류 계산을 통한 시행착오법으로 '저수로 만제 유량'을 설정하여 평균 하상고를 산정하였다. '평균 하상'을 기준으로 계산된 하상변동량 덕분에 여러 시기 하상을 일관된 기준으로 비교할 수 있었다. 한강 하구에서 하상변동 경향은 홍수에 따른 저하와 비홍수기 조석에 따른 상승의 순환으로 드러났다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.658-659
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• 2015

GCM and scenario uncertainties are first investigated for 5 major watersheds (Han River, Paldang dam, Namhan River, Bukhan River and Imjin River watersheds). As a result of this study, it is found that CCSM3-based annual precipitation increases linearly with respect to the 10-year moving average values while CSIRO-based precipitation does not show much of trend. The results from annual DJF mean precipitation show a similar trend with respect to their 10-year moving average values. Both CCSM3- and CSIRO-based annual JJA mean precipitation do not show much of trend toward 21^st century. In general, CCSM3-based precipitation values are slightly higher than CSIRO-based values with respect to their annual and annual JJA mean precipitation values, but CSIRO-based annual DJF mean precipitation values are slightly higher than CCSM3-based values. In case of mean air temperature between CCSM3 and CSIRO during 21^st century, all of results show a clear trend in warming with the passage of time for 5 watersheds. However the upward trends from CCSM3-based values slow down toward end of 21^stcentury while CSRIO-based values increases almost linearly.

• 한국도시환경학회지
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• 제18권4호
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• pp.455-463
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• 2018

본 연구는 영산강 수계에 위치한 하천의 표층 퇴적물 중 유기물과 영양염류들의 농도 분포와 오염도를 평가하기 위하여 수행하였다. 표층 퇴적물 시료는 2015년부터 2016년까지 2년 동안 하천 중 본류 12개 및 지류 4개 지점으로부터 채취하여 입도와 유기물(Ignition Loss, COD, TOC) 및 영양염류(TN, TP, SRP)를 분석하여 평가하였다. 입도 분포는 상류와 하류로 구분하여 모래와 양질사토가 우세하였으나, 상류에 보가 설치된 MS3와 MS6 지점의 경우 각각 양질사토와 미사양토로 나타났다. 상관성 평가 결과, 유기물 항목들은 입도들과 강한 상관관계를 보인 반면 TN을 제외한 영양염류 항목들은 약하게 나타났다. 유기물 및 영양염류 농도의 분포 특성은 상류보다 하류 그리고 보가 설치된 지점들에서 높았고, 특히 MS3 지점의 TP 농도는 상반기보다 하반기에 높은 특성을 보였다. 국내외 오염기준과 비교 평가한 결과, 유기물 및 영양염류 항목들은 전 지점들에서 심각한 오염상태가 아닌 것으로 평가되었다.

• 환경분석과 독성보건
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• 제21권4호
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• pp.292-303
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• 2018

The particle sizes and heavy metal concentrations (Pb, Zn, Cu, Cd, Hg, As, Cr, Ni, Li, Al) of surface sediments of the Yeongsan River were analyzed to assess the distribution and pollution level of heavy metals. The distribution of particle sizes was dominated by sand in the upstream sites (MS1-MS7) and by silt loam in the downstream sites (MS8-ML3), but MS3 and MS6, located slightly upstream of the two weirs, were found to be loamy sand and silt loam, respectively. The concentrations of Pb, Zn, Cu, Cd and Hg were higher at the upstream sites, while As, Cr, Ni and Li were higher at the downstream sites. The heavy metals of crustal origin (As, Cr, Ni and Li) were strongly correlated with particle size, while the other heavy metals (Pb, Zn, Cu, Cd and Hg) were weakly correlated with particle size. Considering their concentrations, most of heavy metals were evaluated as having almost no toxic effects on benthic organisms, at all sites. In addition, anthropogenic contamination by the $I_{geo}$, EF and CF were found to have no impact at most sites, with only low levels of pollution at the others. Using the PLI method, the MS2 and MS3 sites, located upstream, were assessed to be affected by anthropogenic contamination. Most importantly, Zn, Cu and Hg were found to be the elements responsible for most pollution, and they were highest at the upstream sites, implying pollution by domestic sewage and urban discharge.