• Ecology and Resilient Infrastructure
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• v.1 no.2
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• pp.61-67
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• 2014

Dam construction changes flow regime and stream morphology in the downstream reach. These affect the ecosystem of downstream reach. This study provides the assessment of the impact of dam construction on the downstream fish habitat. For this, physical habitat simulations are carried out. The quasi-steady model is used for hydraulic simulation, The hydraulic model used in the present study is capable of simulating the morphological change due to sediment transport. The change of the fish habitat condition is investigated using the flow scenarios before and after the dam construction. Simulation results indicate that the habitat suitability decreases frequently due to hydropeaking after dam construction. In addition, erosion is expected to occur in a reach downstream of dam. This is a long term effect due to the shut-down of sediment supply from the upstream reach.

• Ecology and Resilient Infrastructure
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• v.6 no.3
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• pp.145-153
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• 2019

The present study performed the impact of the change of low-flow channel on aquatic habitat in a reach of the Wonju-cheon Stream, Korea. The target species was Zacco platypus, a dominant species in the middle- and upper-stream of Wonju Cheon. The River2D model was used for the computation of the flow and the habitat suitability index model was used to estimate the quantity and quality of fish habitat using habitat suitability curves. First, for the restoration to low-flow channel, the restoration was conducted in a form close-to-nature flow channel, and the width of the low-flow channel was expanded and reduced. The results indicated that the Weighted Usable Area (WUA) of the target species improved by about 72% when the width of the low-flow channel was expanded, and that the fish habitat decreased by about 25% when the width of the low-flow channel was reduced.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.184-184
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• 2011

하천과 같은 생태계와 생물 서식지 들은 생물학적 요소와 무생물학적 요소간의 다양한 상호작용을 포함하는 복잡한 관계를 맺고 있다. CASiMiR 모델은 선정된 특정종의 서식지 적합도를 결정하기 위해 하천시스템의 수리학적 및 지형학적 특성을 사용하는 모듈형식의 조합으로 모의를 실시하는 프로그램으로 입력되는 자료로는 수심, 유량 등의 수리학적 자료와 하저구성물의 크기 토지피복의 종류 등의 지형학적 자료 등이 필요하다. 또한 어류의 서식지 적합도 지수를 제공하기 위해 선호도 함수를 사용하거나 Fuzzy 모형을 사용한다. 본 연구에서는 이러한 CASiMiR-Fish 모형을 이용해 피라미 종의 Fuzzy 함수로 수통 수위표 지점 상하류 3km 구간에 대한 어류 서식지 모의를 실시하였다.

• Journal of Environmental Impact Assessment
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• v.21 no.6
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• pp.841-857
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• 2012

Preliminary ecological environmental assessments including physico-chemical constituents, water quality, fish fauna analysis, physical habitat health, and ecological health assessment were conducted as a primary step for Jeungchon micro-habitat ecosystem restoration in 2012. Water chemistry analysis of conductivity, dissolved oxygen, chlorophyll-a and etc. indicated that there were no significant differences(p < 0.05) among 6 sites between the headwaters and downstream. Multi-metric model analysis of Qualitative Habitat Evaluation Index(QHEI) showed that brooklets were at "good condition" as a mean QHEI of 158.7(n = 6) and the longitudinal differences of the model values between the sites were minor(QHEI range: 153 - 165). Total fish species and the number of individuals were 12 and 481, respectively, and dominant species were Zacco platypus(49.5%) and Zacco koreanus(36.8%). Tolerance guild analysis showed that the proportion of sensitive species($S_S$) had a negative linear function[$S_S=86.35-0.31(D_H)$; $R^2$ = 0.892, p < 0.01] with a distance from the headwaters, while the proportion of tolerant species($T_S$) had a positive linear function($R^2$ = 0.950, F = 90.28, p < 0.001) with the distance. Trophic feeding guild analysis showed that the proportion of insectivore species($I_n$) had a negative linear function($R^2$ = 0.934, p < 0.01) with a distance from the headwaters, while the proportion of omnivore species($O_m$) had a positive linear function($R^2$ = 0.958, p < 0.001) with the distance. Index of Biological Integrity(IBI) model, based on fish assemblages, showed a "fair condition" as a mean IBI of 23(n = 6), and there was a distinct differences of ecological health between the headwaters(S1 = 30; "good condition") and the downstreams(S6 = 14; "poor condition"). Overall, the preliminary environmental impact assessments suggest that water quality, physical habitat conditions(QHEI model), and ecological health(IBI model) were maintained well, even if the state was not an excellent conditions.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.10-17
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• 2013

History of Instream Flow Incremental Methodology (IFIM) Following the large reservoir and water development era of the mid-twentieth century in North America, resource agencies became concerned over the loss of many miles of riverine fish and wildlife resources in the arid western United States. Consequently, several western states began issuing rules for protecting existing stream resources from future depletions caused by accelerated water development. Many assessment methods appeared during the 1960's and early 1970's. These techniques were based on hydrologic analysis of the water supply and hydraulic considerations of critical stream channel segments, coupled with empirical observations of habitat quality and an understanding of riverine fish ecology. Following enactment of the National Environmental Policy Act (NEPA) of 1970, attention was shifted from minimum flows to the evaluation of alternative designs and operations of federally funded water projects. Methods capable of quantifying the effect of incremental changes in stream flow to evaluate a series of possible alternative development schemes were needed. This need led to the development of habitat versus discharge functions developed from life stage-specific relations for selected species, that is, fish passage, spawning, and rearing habitat versus flow for trout or salmon. During the late 1970's and early 1980's, an era of small hydropower development began. Hundreds of proposed hydropower sites in the Pacific Northwest and New England regions of the United States came under intensive examination by state and federal fishery management interests. During this transition period from evaluating large federal reservoirs to evaluating license applications for small hydropower, the Instream Flow Incremental Methodology (IFIM) was developed under the guidance of the U.S. Fish and Wildlife Service (USFWS).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1B
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• pp.71-78
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• 2012

The habitat suitability is an important factor to estimate the distribution and size of the physical habitat in river. This suitability is also a key factor to decide the ecological flow discharge for the fish. For the ecological analysis in river, accurate values of habitat suitability index for various fishes are necessary. In general, fish habitat is affected by the physical factor of the flow depth and velocity as well as the chemical and biological factors of nutrient and attached algae. Thus, the condition of the fish habitat is expected to be changed with each watershed and tributary. In this study, the habitat suitability indices for fishes were proposed by using the field monitoring data in the rivers of the Han and Geum river watersheds. The proposed indices for three fishes are compared: Zacco platypus, Zacco temminckii, and Coreoleuciscus splendidus. The results show that Zacco platypus has a similar distribution of habitat suitability index in two watersheds. Zacco temminckii and Coreoleuciscus splendidus, however, have different distributions with watersheds. Also, for Zacco platypus, the developed indices at three tributaries of the Han river are compared: Cheng-mi stream, Dal stream, and Hong-cheon stream. The comparision shows that the index in the Cheng-mi stream is different with those in the other rivers. This is expected to be because of a high nutrient concentration at the Cheong-mi stream.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.221-230
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• 2014

In order to restore an ecologically damaged river, freshwater fish which inhabit at the target aquatic ecosystem have a great applicability as one of the essential indicators. Although the informations about the habitat conditions of freshwater fish are key elements reflecting biological, physical, and chemical properties of the aquatic environment, because of the lack of preceding related research and insufficient database with scattered data, they have not been applied effectively for the ecological river restoration projects in Korea. To cope with these problems, based on the nation-wide detailed investigation for domestic freshwater fish habitat conditions, we have selected 70 species considering the possibility for the candidates of flagship species, constructed a database for their population, physical, and chemical habitat properties, and suggested its application methodology for the river restoration projects. In particular, the utilization of the database has been enhanced by the additional statistical analysis to present their resistance and optimum ranges for physical, and chemical habitat properties respectively. It is expected that the database constructed in this study can be utilized for the calculation and evaluation of the appropriate ecological flow rate and target water quality for the selected flagship species (fish), and the basic data for the restoration of river environment.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.516-527
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• 2009

We assessed fish fauna and habitat suitability indexes in the Geum river basin. Field monitoring was conducted for ecological and habitat condition assessment at 23 sites from October 2007 to March 2009. The habitat suitability indexes established for dominant fish species using the monitoring data were employed to assess riverine health conditions such as composition ratio of fish species, richness and dominance indexes, bio-diversity(dominance index, diversity, evenness and richness), and water depth, velocity and substrate size. Twenty-one species(42%) including Rhodeus uyekii and Pseudopungtungia nigra were found endemic out of the 50 species in 11 families sampled during this study period. The most frequently found one was Zacco platypus(34.3%) followed by Z. koreanus(10.2%) and Coreoleuciscus splendidus(8.4%). For Z. platypus, the dominant fish species in the basin, the favored habitat conditions were estimated to be 0.1~0.9 m for water depth, 0~0.9m/s for flow velocity and silt(<0.1mm)~cobbles(100.0~300.0mm) for substrate size, respectively. Overall, it was concluded that the Geum river basin has been relatively well protected from the anthropogenic disturbance for the legally protected species including the endemic species studied in this study.

• Journal of Korea Water Resources Association
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• v.38 no.9 s.158
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• pp.771-778
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• 2005

In this study, flow duration analysis was conducted at the Gumbo stage gauging station due to construction of the Youngchun dam. The flow duration characteristics were $10.49\;m^3/s$ of drought flow, $13.30\;m^3/s$. of low flow, $15.65\;m^3/s$ of normal flow, and $25.00\;m^3/s$ abundant flow before construction of Youngchun dam. But after construction of Youngchun dam, the flow duration characteristics were $2.07\;m^^3/s,\;2.89\;m^3/s,\;4.0\;m^3/s,\;9.36\;m^3/s$ and they had been deteriorated. Applying the Physical Habitat Simulation Model by Instream Flow Incremental Methodology, the Weighted Usable Area(WUA)-Discharge Curve was developed for Zacco Platypus according to the growth stages. Using the WUA-Discharge Curve, the WUA Duration Curve was developed with exceedance probability of daily flow and evaluated fish habitat conditions due to the construction of Youngchun dam. As an evaluation result, the WUA was reduced and fish habitat environment was deteriorated due to the construction of Youngchun dam during the spawning and growth period of Zacco Platypus. However the exceedence probability of the $90\;\%$, irrigation water supply from the Youngchun dam improved flow duration characteristics and Weighted Usable Area as well as fish habitat.

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.119-128
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• 2006

Fish assemblages associated with eelgrass beds and unvegetated area were compared based on specimens collected every month in Jindong Bay. The common fish species were Hexagrammos otakii, Acanthopagrus schlegeli, Lateolabrax japonicus, Pholis nebulosa, P. fangi, Leiognathus nuchalis, Repomucenus valenciennei, and Acanthogobius flavimanus. H. otakii, A. schlegeli, P. nebulosa and L. japonicus were higher abundance in an eelgrass bed than unvegetated area, whereas P. fangi, R. valenciennei and A. flavimanus were higher in unvegetated area. Sillago japonicus, Hippocampus japonica, Takifugu niphobles, Pseudoblennius percoides, Sebastes inermis, Syngnathus schlegeli, Sebastes schlegeli were found in an eelgrass bed, but not in unvegetated area. Most of fish species were primarily small fish species or juveniles of fish species in an eelgrass bed, while larger fish species were found in unvegetated area. The eelgrass bed in Jindong Bay seem to play a nursery role for fishes. Seasonal variations in both species composition and abundance were large in two habitats; higher number of species and individuals occurred May 2002, and April 2002 to July 2002, while biomass was the highest in April 2002 and July 2002. Fish numbers as well as biomass were lowest in January 2002. Species richness, number of individuals and biomass of fishes in an eelgrass bed were significantly higher than those of in unvegetated area. These result suggest that differences in fish species richness and abundances are primarily related to habitat structure. Different habitat preferences were evidenced for the juveniles and adult of several fish species.