• 한국수산과학회지
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• 제54권2호
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• pp.194-207
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• 2021

It is necessary to assess and manage the different elements of the marine ecosystem, such as climate change, habitat, primary and secondary production, energy flow, food web, potential yield, and fishing, to maintain the health of the ecosystem as well as support sustainable development of fishery. We set up an ecosystem model around the Korean peninsula to produce scientific predictions necessary for the assessment and management of marine ecosystems and presented the usability of the model with scenario experiments. We used the Atlantis ecosystem model based on the marine food web; Atlantis is a three-dimensional end-to-end model that includes the information and processes within an entire system, from an abiotic environment to human activity. We input the ecological and biological parameters, such as growth, mortality, spawning, recruitment, and migration, to the Atlantis model via functional groups using existing research and local measurements. During the simulation period (2018-2019), we confirmed that the model reproduced the observed data reasonably and reflected the actual ecosystem characteristics appropriately. We thus identified the usability of a marine ecosystem model with experiments on different environmental change scenarios.

• 한국물환경학회지
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• 제36권6호
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• pp.636-650
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• 2020

A modeling system that can consider the overall water environment and be used to integrate hydrology, water quality, and aquatic ecosystem on a watershed scale is essential to support decision-making in integrated water resources management (IWRM). In adapting imported models for evaluating the unique water environment in Korea, a platform perspective is becoming increasingly important. In this study, a modeling platform is defined as an ecosystem that continuously grows and provides sustainable values through voluntary participation- and interaction-of all stakeholders- not only experts related to model development, but also model users and decision-makers. We assessed the conceptual values provided by the IWRM modeling platform in terms of openness, transparency, scalability, and sustainability. I We also reviewed the technical aspects of functional and spatial integrations in terms of socio-economic factors and user-centered multi-scale climate-forecast information. Based on those conceptual and technical aspects, we evaluated potential modeling platforms such as Source, FREEWAT, Object Modeling System (OMS), OpenMI, Community Surface-Dynamics Modeling System (CSDMS), and HydroShare. Among them, CSDMS most closely approached the values suggested in model development and offered a basic standard for easy integration of existing models using different program languages. HydroShare showed potential for sharing modeling results with the transparency expected by model user-s. Therefore, we believe that can be used as a reference in development of a modeling platform appropriate for managing the unique integrated water environment in Korea.

• 한국물환경학회지
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• 제36권6호
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• pp.592-610
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• 2020

In South Korea, the concept of water environment was expanded to include aquatic ecosystems with the Integrated Water Management implementation. Watershed-scale modeling is typically performed for hydrologic component analysis, however, there is a need to expand to include ecosystem variability such that the modeling corresponds to the social and political issues around the water environment. For this to be viable, the modeling must account for several distinct features in South Korean watersheds. The modeling must provide reasonable estimations for peak flow rate and apply to paddy areas as they represent 11% of land use area and greatly influence groundwater levels during irrigation. These facts indicate that the modeling time intervals should be sub-daily and the hydrologic model must have sufficient power to process surface flow, subsurface flow, and baseflow. Thus, the features required for watershed-scale modeling are suggested in this study by way of review of frequently used hydrologic models including: Agricultural Policy/Environmental eXtender(APEX), Catchment hydrologic cycle analysis tool(CAT), Hydrological Simulation Program-FORTRAN(HSPF), Spatio-Temporal River-basin Ecohydrology Analysis Model(STREAM), and Soil and Water Assessment Tool(SWAT).

• Journal of Ecology and Environment
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• 제43권1호
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• pp.14-21
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• 2019

Background: Stoichiometry plays an important role in understanding nutrient composition and cycling processes in aquatic ecosystems. Previous studies have considered C:N:P ratios constant for both DOM (dissolved organic matter) and POM (particulate organic matter). In this study, water samples were collected in the six major rivers in Korea and were incubated for 20 days. C:N:P ratios were determined during the time course of the incubations. This allowed us to examine the changes in N and P contents of organic matter during decomposition. Results: POM and DOM showed significant differences in N and P content and the elemental ratios changed during the course of decomposition; DOM showed higher C:N and C:P ratios than POM, and the C:N and C:P ratios increased during decomposition, indicating the preferential mineralization of P over N and N over C. Conclusions: The N and P contents of organic matter in aquatic ecosystem are far from constant and vary significantly during decomposition. More detailed information on the changes in C:N:P ratios will provide improved understanding of decomposition processes and improved modeling of aquatic ecosystems.

• 한국물환경학회지
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• 제36권6호
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• pp.621-635
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• 2020

Water quality models are scientific tools that simulate and interpret the relationship between physical, chemical and biological reactions to external pollutant loads in water systems. They are actively used as a key technology in environmental water management. With recent advances in computational power, water quality modeling technology has evolved into a coupled three-dimensional modeling of hydrodynamics, water quality, and ecological inputs. However, there is uncertainty in the simulated results due to the increasing model complexity, knowledge gaps in simulating complex aquatic ecosystem, and the distrust of stakeholders due to nontransparent modeling processes. These issues have become difficult obstacles for the practical use of water quality models in the water management decision process. The objectives of this paper were to review the theoretical background, needs, and development status of water quality modeling technology. Additionally, we present the potential future directions of water quality modeling technology as a scientific tool for national environmental water management. The main development directions can be summarized as follows: quantification of parameter sensitivities and model uncertainty, acquisition and use of high frequency and high resolution data based on IoT sensor technology, conjunctive use of mechanistic models and data-driven models, and securing transparency in the water quality modeling process. These advances in the field of water quality modeling warrant joint research with modeling experts, statisticians, and ecologists, combined with active communication between policy makers and stakeholders.

• 한국수산과학회지
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• 제35권4호
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• pp.386-394
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• 2002

패류 양식 해역의 서식 환경과 양식 생물간의 상호 관계를 파악하고 지속적인 생산 방안을 위하여 굴 성장과 관련된 생리 대사 과정인 섭이, 소화, 배설, 호홉 등의 제 인자를 수식화하여 기존에 개발된 생태계모델 (EUTRP2)에 연계하여 환경용량 산정 모델을 구축하였다. 구축된 모델이 굴 성장과 서식환경과의 상호관계를 재현함에 있어 타당성 여부를 검정한 결과, 굴 성장에 따른 서식환경 중 식물플랑크톤 현존량이 감소하고 영양염 농도가 증가하는것으로 보아, 패류양식해역의 생태계 환경관리를 위한 도구로 사용할 수 있는 것으로 나타났다. 그리고, 생태계 구성 요소에 영향을 미치는 생물 인자에 대한 민감도 분석 결과, 구성 요소들은 식물플랑크톤의 증식 속도와 높은 민감도를 보였고, 굴 성장의 경우 동물플랑크톤 최대 섭이 속도와는 민감도가 낮은 반면, 식물플랑크톤 증식 속도, 사멸 속도와 굴의 먹이 흡수 효율에 매우 민감하였다.

• Water Engineering Research
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• 제7권1호
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• pp.29-41
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• 2006

The Imha watershed is vulnerable to severe erosion due to the topographical characteristics such as mountainous steep slopes. Sediment inflow from upland area has also deteriorated the water quality and caused negative effects on the aquatic ecosystem of the Imha reservoir. The Imha reservoir was affected by sediment-laden density currents during the typhoon 'Maemi' in 2003. The RUSLE model was combined with GIS techniques to analyze the mean annual erosion losses and the soil losses caused by typhoon 'Maemi'. The model is used to evaluate the spatial distribution of soil loss rates under different land uses. The mean annual soil loss rate and soil losses caused by typhoon 'Maemi' were predicted as 3,450 tons/km2/year and 2,920 ton/km2/'Maemi', respectively. The sediment delivery ratio was determined to be about 25% from the mean annual soil loss rate and the surveyed sediment deposits in the Imha reservoir in 1997. The trap efficiency of the Imha reservoir was calculated using the methods of Julien, Brown, Brune, and Churchill and ranges from 96% to 99%.

• Ecology and Resilient Infrastructure
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• 제2권3호
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• pp.198-205
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• 2015

기후변화에 의한 수생태계의 영향은 수생생물의 생리작용의 변화에서부터 종분포에 이르기까지 광범위할 것으로 예상된다. 본 연구에서는 기후변화에 따른 금강유역의 어류 종분포를 예측하기 위하여 비출현 정보를 요구하지 않고도 좋은 예측력을 가지고 있는 MaxEnt 모형을 활용하였다. 금강유역 134개 지점의 2007년부터 2009년까지 어류 출현 자료 (고유종 17종 포함 총 47종)와 9개의 환경인자 (월별 최저기온, 최고기온, 평균기온, 강수량, 최저수온, 최고수온, 평균수온, 고도, 경사)를 사용하여, RCP 8.5 기후변화 시나리오에 따라 2050년과 2100년의 어류 종분포를 예측하였다. MaxEnt 모형은 평균 0.798의 적절한 모형적합도를 보여 주었으며, 종분포 예측에 기여도가 높은 환경인자는 고도, 강수량, 최저수온 순이었다. 기후변화가 진행됨에 따라 얼룩동사리와 줄납자루와 같은 고유종의 출현확률은 감소한 반면, 배스와 블루길과 같은 외래종의 출현확률은 증가하였다. 특히 2100년에는 5종 (줄몰개, 미꾸라지, 강준치, 줄납자루, 칼납자루)의 어류가 금강유역에서 더 이상 서식하지 못하는 것으로 예측되었다. 그리고 기후변화에 따라 종풍부도가 높은 지역이 금강유역 내에서 북상하는 것으로 예측되었다. 이러한 결과는 기후변화로 인한 수온 상승이 금강유역 수생태계의 교란을 심화시킬 수 있다는 것을 의미한다.

• 한국수자원학회논문집
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• 제54권9호
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• pp.719-730
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• 2021

본 연구에서는 상류의 휴·폐광산을 비롯한 다양한 점오염원과 비점오염원으로부터 유실되는 오염물질의 영향을 받는 안동호를 대상으로 수질 및 수생태 모델인 SWAT-WET을 구축하고, 적용성을 평가하고자 한다. 안동호르 유입되는 오염물질에 대한 정량적인 평가를 위해 유역모델인 SWAT을 안동댐 유역(1,584 km²)을 대상으로 구축하여, 검보정을 수행하였다. 유출량과 수질 부하량(SS, T-N, T-P)에 대한 검보정 결과 R²는 각각 0.76, 0.69, 0.84, 0.60 이상으로 분석되었다. 검보정된 SWAT의 유출량과 영양물질의 농도를 WET의 입력자료로 적용하여 안동호에 대한 수질, 수생태 모델 WET을 구축하였다. WET의 매개변수 민감도 분석 결과를 이용하여, 안동호의 수온, 용존산소, 수질농도(T-N, T-P)를 대한 검보정을 수행하였다. 검보정 결과 PBIAS는 각각 +19%, -13%, +4%, +26.5% 로 분석되었으며, 관측 자료를 유의한 수준으로 모의하는 것을 확인하였다. 저서동물의 관측 건중량(gDW/m²)은 0.5 이하였으나 모의 건중량의 평균은 0.8로 분석되었으며, 이는 WET 모델이 더 넓은 개념의 저서동물을 고려하기 때문으로 나타났다. 관측자료 부족으로 정확한 검보정은 어렵지만, 유역모델과의 연계를 통한 장기간 모의와 상류 유역환경변화가 호소에 미치는 영향을 분석할 수 있으므로 안동호의 수환경 관리를 위한 기초 자료로 활용될 수 있을 것으로 판단된다.

• Journal of Ecology and Environment
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• 제36권1호
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• pp.73-83
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• 2013

The object of this study was to evaluate lotic ecosystem health using multiple eco-metric approaches such as water chemistry diagnosis, physical habitat health evaluations, and biological integrity modeling at 100 streams of four major watersheds. For the study, eight chemical water quality parameters such as nutrients (N, P) and organic material were measured and 11-metric models of Qualitative Habitat Evaluation Index (QHEI) and multiple eco-metric health assessment model (MEHA) were applied to the four major watershed. Nutrient analysis of nitrogen (N) and phosphorus (P) in all watersheds indicated a eutrophic state depending on the locations of sampling streams. Physical habitat health, based on the QHEI model, averaged 114 (range: 56 - 194), judging as a "good condition" by the criteria of Plafkin et al. (1989). In addition, primary (H1 - H4), secondary (H5 - H7), and tertiary habitat metric variables (H8 - H11) were analyzed in relation to the physical habitat degradations. The plots of tolerant species ($P_{TS}$) and sensitive species ($P_{SS}$) to water quality showed that the proportions of $P_{TS}$ had positive linear functions with nutrients, and that the $P_{SS}$ had inverse linear relations with the chemical variables. The model of eco-metric health assessment showed that mean MEHA was 20.4, indicating a fair condition. Overall, our data suggest that water chemistry, based on nutrients and organic matter, directly modified the trophic structures in relation to food chain in the aquatic ecosystems, and then these directly influenced the compositions of tolerance/sensitive species, resulting in degradations of overall ecological health.