• 한국환경복원기술학회지
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• 제11권2호
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• pp.40-54
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• 2008

Small and large dams are installed in the course of a stream for maintaining the water level of the stream or obtaining agricultural water. Currently about 18,000 of them are installed in Korea to supply water. However, the environmental problems of small dams are well known : the interruption of stream eco-corridors, deterioration of water quality in the upper reaches of the small dam, changes in the habitats of riparian organisms, damages to the stream scenery. In a very few of these small dams artificial eco-corridors like fishways are installed, but the number is very minimal.Accordingly, to efficiently restore stream eco-corridors by removing these small dams, it will be necessary to closely examine physical impacts, such as changes in the riverbed and changes in the shape of the stream caused by the removal, chemical impacts, such as changes in water quality, and transport and accumulation of contaminated sediments and biological impacts, such as changes in the habitats of organisms, and develop related technologies in advance, and have these technologies verified through demonstration application in the sites. In this study, we analyzed the physical, chemical and ecological impacts of the removal of the above-mentioned small dams, and conducted a research on the demonstration small dam removal project for a spot investigation. As a result, the small dam removal will restore the eco-corridor, there by improving the habitat of fishes and crustaceans. The number of major underwater organisms inhabiting the Gokreungcheon, such as Korean spotted sleepers, Chinese minnows, Microphysogobio yaluensis, Abbottina rivularis, stone morokos, striped shinners, long-nosed barbels, and Chinese mitten crabs, is expected to increase, and the food chain in the ecosystem will improve so that species diversity will improve as well.

• 한국수산과학회지
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• 제48권4호
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• pp.542-554
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• 2015

Grain size, the content of ignition loss (IL), and the concentrations of chemical oxygen demand (COD), acid volatile sulfide (AVS), and trace metals (Fe, Mn, Cu, Pb, Zn, Cd, Cr, As, and Hg) in surface sediments from the Taehwa River estuary, Ulsan, were measured to evaluate pollution levels and potential ecological risks of organic matter and trace metals in estuarine sediment. The mean grain size (Mz) of sediments in the study region ranged from $-0.8-7.7{\varphi}$ (mean $2.8{\pm}2.4{\varphi}$). Surface sediments in the upstream region of the Taehwa River were mainly composed of coarse sediments compared to the downstream region. The concentrations of IL, COD, AVS and trace metals in the sediment were much higher at downstream sites of Myeongchon Bridge in the vicinity of industrial complexes than at upstream sites of those in the vicinity of the residential areas due to the anthropogenic input of organic matter and trace metals by industrial activities. On the basis of several geochemical assessment techniques [sediment quality guidelines (SQGs), enrichment factor (EF), geoaccumulation index ($I_{geo}$), pollution load index (PLI) and ecological risk index (ERI)], the surfaces sediments in the study region are not highly polluted for trace metals, except for As. However, the higher concentrations in downstream study regions of the Taehwa River could impact benthic organisms including shellfish (i.e. Manila clam) in sediments.

• 한국물환경학회지
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• 제27권3호
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• pp.349-356
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• 2011

This study, which evaluated the contribution of the real economic value and system in the Nakdong River Basin, estimated the emergy analysis for environmental accounting of the TMDL program. And an environmental accounting for TMDL is evaluated before and after adopting TMDL program respectively. The value of emergy after adopting the TMDL was 7.90 E+20 sej/yr. Although the real yield of the river after governmental investment was high (before: 9.7118 E+20 sej/yr and after: 9.7224 E+20 sej/yr), the effects of improvement was not great, in terms of an investment cost. The benefit/cost ratio resulted from environmental accounting has decreased from 1.493 to 1.230 due to the cost of managing treatment facilities. The method of improving water quality in the Nakdong River Basin by the TMDL program should be changed into an ecological treatment facilities using resources efficiently from a control of water quality depending on expansion of the wastewater treatment facilities and advanced treatment plant using high cost and non-renewable energies.

• 한국환경복원기술학회지
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• 제26권6호
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• pp.1-19
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• 2023

This study aimed to identify the characteristics of the plant growth forms within the Amsa-dong Ecological and Landscape Conservation Area, a floodplain along the Han River, based on 20 years of flora monitoring data. The analysis revealed that there were 106 taxa identified in 2003, 158 taxa in 2006, 107 taxa in 2013, and 202 taxa in 2020. Compared to 2003 and 2013, the number of taxa increased significantly by approximately 50 taxa in 2006 and around 100 taxa in 2020. It is presumed that this is due to the influx of seeds caused by the flooding of the Han River due to record-breaking heavy rains during the rainy seasons of 2006 and 2020, leading to a rapid increase in the number of taxa. This was also confirmed in aquatic plants(HH) as a result of comparison of life style analysis by year. The analysis revealed that there were 19 aquatic plant(HH) in 2003, 32 aquatic plant(HH) in 2006, 9 aquatic plant(HH) in 2013, and 30 aquatic plant(HH) in 2020. The number of aquatic plants(HH) increased slightly in 2006 and 2020 compared to 2003 and 2013, and the influx of rare aquatic plants in urban rivers was confirmed. Consistent with the results of the vascular flora analysis above, these plants are believed to have been introduced from the upper reaches of the Han River when the Han River flooded due to heavy rains during the record-breaking rainy season in 2006 and 2020.

• 한국환경복원기술학회지
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• 제18권6호
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• pp.151-165
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• 2015

This study surveys and analyzes the ecology of Gangseo area to be developed near Nakdonggang River and West Nakdonggang River in Busan - before its development. With the result of the surveys as its basis, the study also finds ways to conserve the area's bird habitats in response to the planned development. According to the site surveys over four seasons, West Nakdonggang River which is near the targeted development area is a wintering ground for migratory birds. Some representative bird types in this area are ducks, geese, and other water birds. There are even six legally protected species. The average altitude of their flight is calculated to be $92.4{\pm}18.8m$ and the main purpose for the migration is determined to be for food. According to evalution of the conservation value of the area, Nakdonggang River and West Nakdonggang River turns out to have the highest conservation value. Other areas are developable as long as it was environmentally friendly. Therefore, this study suggests incorporation of ecological parks and biotopes within the targeted development area along with the proposal for spaces in the surroundings where the wintering birds can rest and feed. Especially for the wintering birds that rest at Nakdonggang River and West Nakdonggang River, their flight direction and pattern was examined to determine that their resting ground should be located 50~100m off of the river bank. Furthermore, this study proposes ways to maximize bird habitat by building ecological corridors between the agricultural channel and other small streams in the targeted development area and the habitats in the surroundings. Lastly, the study suggests the construction of low buildings, at most 20m in height, near Nakdonggang River and West Nakdonggang River considering the birds' flight altitude and direction.

• 한국물환경학회지
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• 제25권6호
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• pp.951-963
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• 2009

The community structure and ecological characteristics of fish community in Lake Paldang were investigated from May to September 2008. During the survey period, 53 species belonging to 13 families were collected. Dominant species was Squalidus japonicus coreanus representing 81.8% of total number and 25.7% of total biomass of collected fish and subdominant species was Lepomis macrochirus representing 3.3% of total number and 18.9% of total biomass of collected fish. There were 20 Korean endemic species (38% of collected species number) including Cottus koreanus and 4 exotic species (7.5%) including Micropterus salmoides. The similarity analysis of fish communities among water areas of Lake Paldang using UPGMA showed that fish community of North-Han River was similar to that of South-Han River area and was different from that of Gyeongan River area. Long-term variation of fish community from 1972 to present study in Lake Paldang showed decrease of the species numbers after dam construction until 1994, and gradual increase from 1996 to present study indicating the disturbance of lentic system by dam construction in the 1980s. The increase of species number in the late 2000s may results in part from the increase of survey sites of successive studies. L. macrochirus which was designated as a domestic ecosystem-disturbing alien species with wide food niche have shown more than 20% of relative abundance since 1996 indicating the adverse effect on not only fish community but also aquatic ecosystem food web of Lake Paldang.

• 대한환경공학회지
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• 제36권3호
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• pp.221-230
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• 2014

수생태적 건전성이 훼손된 하천을 자연형 생태하천으로 복원하고자 할 경우, 대상 수생태계에 서식하고 있는 담수어류는 핵심적 지표생물로서의 활용 가능성이 매우 크다. 어류의 서식환경에 대한 정보는 수환경의 생물학적 및 물리 화학적 특성을 반영할 수 있는 핵심적 요소임에도 불구하고 관련 연구가 미비하고 기존 데이터 또한 산재해 있는 등 데이터베이스(DB)화가 미흡하여 생태하천 복원사업의 추진 과정에서 이를 충분히 연계하지 못하고 있는 실정이다. 이러한 문제에 대응하기 위하여 국내에 서식하고 있는 주요 담수어종의 서식환경에 대한 전국 규모의 상세조사 결과를 바탕으로, 깃대종으로서의 활용도가 높을 것으로 판단되는 70종을 선정하여 각 어종별로 개체군 특성, 물리적 및 이화학적 서식특성을 DB화하고, 이를 생태하천 조성사업에 활용하는 방안을 제시하였다. 특히, 물리적, 이화학적 서식환경에 대해서는 서식범위와 최적범위를 산출하는 통계분석을 추가 수행하여 DB의 활용성을 제고하였다. 본 연구에서 구축한 DB는 생태하천 복원시 선정된 깃대종(어류)에 적합한 생태유량과 목표수질의 산정, 평가 및 서식환경 복원을 위한 기초자료로 활용될 수 있을 것으로 기대된다.

• 한국습지학회지
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• 제21권spc호
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• pp.16-27
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• 2019

자연적 기후변화와 댐 건설로 인한 인위적 수문환경의 변화로 인하여 하천의 유황(flow regime) 변화가 발생하며, 이러한 유황의 변화는 하천의 생태계뿐만 아니라 하천의 물리적 구조와 어류서식처 등에도 심각한 변화를 야기한다. 본 연구에서는 감천유역의 부항댐 건설로 인하여 나타난 수문특성변화와 동시에 하천의 생태건강성 및 수질, 하천단면 변화를 분석하였다. 감천의 유황 변화를 정량적으로 파악하기 위해 수문변화지표(Indicators of Hydrologic Alteration, IHA)에 의한 분석 결과, HA(Hydrologic Alteration)가 대부분 ±1 이상으로 댐 건설 후 하천생태계에 다양한 변화가 발생한 것으로 판단된다. 또한, 생태건강성등급 및 수질은 각 요소마다 상이한 반응이 나타났으며, 하천의 하상 및 단면의 경우에는, 댐 건설 후에 하상 단면의 저하가 뚜렷하게 나타났다. 본 연구의 성과는 하천의 유황 변화에 의한 하천생태계의 변화를 평가하기 위한 효율적인 방법으로 활용될 수 있을 것으로 기대된다.

• Ecology and Resilient Infrastructure
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• 제3권4호
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• pp.307-314
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• 2016

최근 하천복원 사업은 과거 인공적인 부분을 개선하는 범위를 벗어나 격리차단된 구하도까지 복원하는 수준에 이르렀다. 구하도 복원은 하천 제방과 같은 종적 구조물에 의해 차단된 공간의 수리적 연결성 회복이 중요하다. 그러나 하천복원이 적절히 수행되었는지 관한 평가방법이 부족한 상황이기에 본 연구에서는 대상하천에서의 생태적 연결성 평가를 위한 수단을 제공하고자 한다. 이 연구에서 강우에 의한 유역유출 및 하도흐름 해석이 동시에 가능한 1차원 수치모형을 개발하여 청미천 유역에 적용한 바 있다. 특히 이 연구에서 1차원의 홍수추적 결과를 2차원의 공간분포로 변환시키고 시간에 따른 2차원의 수리특성으로부터 서식처적합도까지 산출하여 연결성 회복정도를 평가하는 수치모형을 개발하였으며, 이를 청미천 구하도 복원지역에 적용하였다. 복잡할 뿐만아니라 시간도 많이 소요되는 2차원의 분석을 수행하지 않고서도 1차원 수리특성 결과를 확장해서 2차원 수리특성을 쉽게 구할 수 있도록 한 것이 본 연구의 특징이다. 본 연구의 결과를 이용하면 구간별 대상종별 서식처적합도를 용이하게 산정할 수 있다.

• 한국지리정보학회지
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• 제7권3호
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• pp.57-69
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• 2004

본 연구는 낙동강 하구 일대의 생태계 변화와 생태 관련자료를 GIS DB로 구축하고 생태지도를 작성하였다. 생태지도 작성을 위해 1984년 11월 21일, 1997년 5월 17일에 촬영된 공간해상도 30m의 Landsat TM 위성영상과 국립지리원에서 발행된 1:25,000 수치지형도, 부산시에서 조사한 생물현황 자료를 바탕으로 DB를 구축하였다. 생태지도를 작성하기 위해, 첫째, 낙동강 하구 생태계 조사 보고서와 현재까지 진행된 생태지도에 대한 문헌 연구, 둘째, 시계열적 토지피복분류도 제작, 셋째, 동 식물상, 수질 등 생태계 항목별 DB 구축과 3단계 방식에 의한 생태계 평가, 최종적으로는 이러한 분석 결과를 바탕으로 생태계 관리를 위한 생태지도를 작성하였다.