• 한국환경과학회지
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• 제17권2호
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• pp.149-162
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• 2008

Aquatic and riparian vegetation of river ecosystems are very important both in ecological and management perspectives. Vegetation surveys were conducted to understand the characteristics of riparian vegetation in the mid and lower reaches of the Nakdong River, Korea. A total of 68 families and 260 species were identified at eleven survey sites. The numbers of taxa were similar to those reported in a previous survey in 1996,but the percentage of naturalized plants increased more than two times compared to that in the previous survey. Survey sites near Yangsan Bridge and Nambu Park in Yangsan showed the highest percentage of naturalized plant species. Urbanization indices of the survey sites were high at 18.8% on average. Therophytes were the most dominant plant life form at the survey sites with 39.2% of total plants identified, followed by phanerophytes (19.2%), hemicryptophytes (18.9%), aquatic plants (13.9%), cryptophytes (5.8%), and chamaephytes (3.1%). The relative composition of hemicryptophytes decreased whereas those of therophytes and chamaephytes increased compared to those in the survey in 1996. This may be due to increase in dryness of riparian soils or degradation of riparian areas. Plant compositions at sites near Jeokpo Bridge and Hwoicheon suggest that the composition and distribution of riparian vegetation are affected by land use pattern surrounding riparian areas or human accessibility to the areas.

• 환경영향평가
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• 제17권3호
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• pp.189-200
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• 2008

As a transition zone between terrestrial and aquatic ecosystems, riparian areas of rivers and streams play significant roles in production and decomposition for river and stream systems. Understanding of the physical and ecological characteristics of riparian areas are, therefore, important for the management of river and stream systems. It is especially important to understand the characteristics of riparian areas for the Nakdong River in Korea which has a large watershed area and diverse land uses. This study aimed at collecting field data, according to stream types, which are essential for the management of riparian areas of the middle and lower reaches of the Nakdong River, Korea. Most riparian areas surveyed in this study had roads within 100 meters from river edges. Distances from water edge to banks were less than 1m for most riparian areas neighboring agricultural lands, indicating that those areas might be very vulnerable to pollutant inputs from non-point sources. Water quality data indicated that soil erosion in the riparian areas could be a major source of phosphorus input to the Nakdong River and land use patters might have a significant influence on nitrogen concentration in the river. Heavy metal concentrations in soils of the riparian areas of the river were below soil quality standards, except arsenic and chromium. Vegetation surveys showed that therophytes were the most frequently occurred riparian plants in the Nakdong River. Number of aquatic plant species increased downstream, with the most diverse aquatic plants observed in wetlands and irrigation canals of the West Nakdong River. Occurrence rate of naturalized plants and urbanization index were high in the survey sites adjacent to urban and agricultural areas.

• 환경생물
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• 제17권2호
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• pp.139-146
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• 1999

온천배수에 의한 주변 식물상의 변화를 구명하기 위하여 고창 석정온천, 전주 죽림온천, 익산 왕궁온천을 대상으로 1997년부터 1998년까지 10회에 걸쳐서 조사하였다. 계절별 온배수에 의한 주변 식물종의 출현은 외부기온이 비교적 낮은 계절에 대조구보다 실험구에서 더 많은 종이 나타났다. 피도가 높은 종은 계절에 따라 바뀌지만 대조구와 실험구에서 차이가 없었다. 온배수에 의한 식물 엽면적의 계절별 변화는 대체로 2월, 4월, 10월에는 대조구값이 오염지역 식물보다 낮았다. 이것은 온배수에 의한 온도상승이 요인으로 판단되었다. 계절별 식물의 생체량과 건중량은 외부기온이 비교적 낮은 때에는 대조구 값이 실험구 값보다 저조하였다. 온천 배수지역의 식물체내에 함유된 무기염류의 분석결과 석정온천 지역의 Cu, Zn, Ni, Pb는 대조구보다 오염지역에서 4월부터 9월까지 증가하였고 10월에는 감소하였다. 왕궁온천 지역의 식물체 내에는 Zn, Pb함량이 대조구보다 오염지역의 값이 높았다. 그래서 온배수에 의한 식물의 영향은 기온이 낮은 계절에 나타나고, 기온이 높은 계절에 식물은 회복되는 것으로 밝혀졌다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 추계 학술대회 논문집
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• pp.321-331
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• 2005

과학기술부고시 2003-12호 "원자로시설부지 수문 및 해양특성 조사평가 기준" 이 신규 제정되어, 원전 액체 방사성 유출물에 대한 삼차원적인 해양확산 평가 필요성이 커지고 있다. 한국수력원자력(주)와 전력연구원은 신고리, 신월성, 신울진 원 전등 다수의 신규원전 건설이 계획 또는 추진되고 있는 동해안을 대상으로 광역 및 부지별 입지특성을 반영한 해양확산 평가기술을 개발하고 있다. 동해안의 해수유동은 동해 해수순환에 의해 영향을 받기 때문에 원전 주변의 방사성 물질의 해양확산을 보다 정확히 평가하기 위해서는 동해 해수순환에 대한 이해가 선행되어야한다. 따라서 본 연구에서는 일본 큐슈대학교 응용역학연구소에서 개발한 RIAMOM 모델을 근간으로 동해 해수순환 모델링을 수행하였다. 모델 영역은 $126.5^{\circ}E{\~}142.5^{\circ}E$ $33^{\circ}N{\~}52^{\circ}N$, 수직층은 20개로 나누었다. 이 모델은 JODC, KNFRDI, 그리고 ECMWF로 부터 구하였다. 모델링 결과, 동해 해수순환을 비교적 잘 모의하고 있는 것으로 나타났다. 향후 모델링 결과를 정량적으로 평가하기 위해 인공위성 추적 부이를 이용하여 확산 검증 실험을 실시할 예정이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.142-142
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• 2023

Humans inevitably and continuously produce wastewater in daily life worldwide. To decrease the degradation of river water bodies and aquatic ecosystem therein, humans have built systems at different scales to collect, drain, and treat household-produced wastewater. Particularly, municipal wastewater treatment plants (WWTPs) with centralized controls have played a key role in reducing loads of nutrients in domestic wastewater for the last few decades. Notwithstanding such contributions, impaired rivers regarding water quality and habitat integrity still exist at the whole river basin scale. It is highly attributable to the absence of dilution capacity of receiving streams and/or the accumulation of the pollutant loads along flow paths. To improve the perspective for individual WWTPs assessment, the first crucial step is to achieve systematic understanding on spatial distribution characteristics of all WWTPs together in a given river basin. By taking the initiative, our former study showed spatial hierarchical distributions of WWTPs in three large urbanized river basins in Germany. In this study, we uncover how municipal WWTPs in the contiguous United States are distributed along river networks in a give river basin. The extended spatial scope allows to deal with wide ranges in geomorphological attributes, hydro-climatic conditions, and socio-economic status. Furthermore, we identify the relation of the findings with multiple factors related to human activities, such as the spatial distribution of human settlements, the degree of economy development, and the fraction of communities served by WWTPs. Generalizable patterns found in this study are expected to contribute to establishing viable management plans for recent water-environmental challenges caused by WWTP-discharges to river water bodies.

• Fisheries and Aquatic Sciences
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• 제3권2호
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• pp.78-82
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• 2000

The influence of daily water temperature changes on chemiluminescent (CL) response of phagocytes, plasma glucose level and mortality in cultured gray mullet (Mugil cephalus) was investigated. Among three experimental temperature groups, the fish in group I and group II were maintained constantly at $27^{\circ}C$ and $29^{\circ}C$, respectively, and those in group III were suffered daily elevation of water temperature from $27^{\circ}C$ to $29^{\circ}C$ for 5 hours, then restored again to $27^{\circ}C$. After 1 week of maintaining at each experimental tank, the fish in group III showed significantly lower CL peak value (p < 0.01) and higher plasma glucose levels (p < 0.05) than those in group I and group II. The cumulative mortality of group III was $86.9\%$ within 3 days after being subjected to acute handling stress. On the other hand, the cumulative mortalities of group I and group II were $12.5\%$ and $19.2\%$, respectively. In conclusion, gray mullet farms, especially, in the vicinity of thermoelectric power plants should avoid stressing the fish during periods of high water temperature.

• 한국환경복원기술학회지
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• 제21권4호
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• pp.25-42
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• 2018

The purpose of this study is to present the basic data for management of ecologically restored stream by surveying and analysing the vascular plants distributed in Chunghyocheon stream, Gyeongju-si. The survey of vascular plants in this site was conducted before and after restoration. The number of vascular plants were summarized as 276 taxa including 68 families, 188 genera, 242 species, 1 subspecies, 29 varieties and 4 forms. The rare plants were 2 taxa including Prunus yedoensis Matsum. and Iris ensata var. spontanea (Makino) Nakai, and the Korean endemic plant was Lespedeza maritima Nakai. The specific plants by floristic region were 13 taxa including 1 taxa of grade V, 3 taxa of grade III, 1 taxa of grade II and 8 taxa of grade I. The naturalized plants were 62 taxa including Persicaria orientalis (L.) Spach, Lepidium virginicum L., Poa compressa L. and so forth. The invasive alien plants were 3 taxa including Ambrosia artemisiifolia L., Aster pilosus Willd. and Lactuca scariola L.. The hydrophytes were 34 taxa including 26 taxa of emergent plant, 1 taxa of floating-leaved plant, 2 taxa of free-floating plant and 5 taxa of submerged plant.

• 한국환경복원기술학회지
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• 제15권2호
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• pp.57-75
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• 2012

This study was carried out to investigate the flora of estuary regions, Namdaecheon, Jusucheon, and Maeupcheon, placed in the east coast of Gangwon-do. The vascular plants were summarized as 441taxa, including 90 families, 277 genera, 388 species, 2 subspecies, 35 varieties, and 6 forms. Number of species in each investigated region was 271taxa of Namdaecheon, 247taxa of Jusucheon, and 285taxa of Maeupcheon, respectively. Among the investigated 441taxa, 7 Korean endemic, 5 rare plants and 37 specially designated plants by Ministry of Environment were also included. Aquatic and hydrophyte plants were collected 41taxa, and the thinophyte and halophyte plants were investigated 22taxa. The naturalized plants were 59taxa, and the percent of naturalized plant species was estimated as 13.3%. Based on the floristic composition, Maeupcheon was estimated as well conserved estuary region among the investigated 3 rivers.

• Ocean and Polar Research
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• 제41권2호
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• pp.89-97
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• 2019

Long chain plant waxes (n-alkanes, n-alkanoic acids, and n-alcohols) and their carbon isotopic compositions (${\delta}^{13}C$) in geologic archives are valuable tools for paleovegetation reconstruction. However, the sensitivity of different plant wax constituents to vegetation shift is not well understood. This study explores controls on the variation in ${\delta}^{13}C$ values of long-chain n-alkanes ($C_{27}$ to $C_{33}$) and n-alkanoic acids ($C_{26}-C_{30}$) in the Gulf of Mexico core sediments (ODP 625B) near the Mississippi River delta. n-Alkanoic acids' ${\delta}^{13}C$ values were higher than those of n-alkanes by 1-2‰ on average and such a pattern is the opposite from their isotope fractionation observed in living plants: 1-2‰ smaller in n-alkanes than n-alkanoic acids. We attribute this offset to contributions from aquatic plants or microbes that produce high concentrations of $^{13}C-enriched$ long-chain n-alkanoic acids. The sensitivity of n-alkanes and n-alkanoic acids to vegetation and climate varied among chain lengths. The $n-C_{33}$ alkanes were most sensitive to $C_4$ grassland expansion among n-alkane homologues, while no specific trend was observed in n-alkanoic acids. This is due to the similarity in n-alkanoic acid concentrations between $C_3$ and $C_4$ plants by homologues and low terrestrial plant-derived n-alkanoic acid contributions to the sediments. The results of this study suggest that long chain n-alkanoic acids' ${\delta}^{13}C$ values in sediments may be influenced by contributions from different sources such as aquatic plants or microbial inputs and therefore interpretations regarding this matter should be cautiously formulated. We suggest that there is a need for further studies on characterizing long-chain n-alkanoic acids ($C_{26}-C_{34}$) in aquatic plants and microbes from various climates and environments in order to investigate their production and integration into sedimentary archives.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.152-152
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• 2003

The majority of the SKYBIO will be used in the treatment of water in food processing plants, swimming pools and cooling towers, in the manufacture fabric softeners in Australia. Most will eventually be released into domestic sewage system as a consequence of product use. The SKYBIO is not readily biodegradable (0% over 28 days), and is expected to have a low partition coefficient and high water solubility (285 g/L), all indicating that the material would be mobile in both aquatic and terrestrial compartment. The PEC/PNEC ratio for the aquatic environment is 56. This value is significantly greater than 1, indicating an immediate concern to the aquatic compartment. However as a consequence of it's cationic character, the SKYBIO will be expected to associate to negatively charged organic matter in soil and sediment.