• 한국농공학회논문집
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• 제64권4호
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• pp.55-64
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• 2022

The objectives of this study were to assess physical habitat suitability of fish species for different life cycle stages and to suggest appropriate ecological stream flows in a Bokha downstream reach. A dominant species of Zacco platypus was selected as the study fish of which three stages of spawning, juvenile and adult in life cycle were considered into assessment. The stream hydraulic environment was calibrated with HEC-RAS before the PHABSIM simulation. The hydraulics of flow velocity and depth were used to estimate Weighted Usable Area (WUA) by multiplying respective habitat suitability indices with stream area. Overall the WUAs tend to be great in gentle slopes with relatively shallow water depth regions. Maximum WUAs, ie, candidate for ecological flow rates were 1 m³/s, 7 m³/s and 8 m³/s for the respective spawning, juvenile and adult stages of Zacco platypus. Since the ecological flow rates for juvenile and adult stages appeared to be is greater than the abundant flow rate (3.67 m³/s) for the study reach, additional water supply may be needed but should be cautious to avoid the spawning period of Apr through May from the stream water management perspective.

• 한국지형학회지
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• 제28권2호
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• pp.1-13
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• 2021

It is very important to secure sufficient river maintenance flow for the ecosystem, since the ecosystem in the downstream section of the dam is greatly affected by the stream maintenance flow from the dam. However, the amount of discharge from the Seomjingang Dam is decreasing year by year, this study estimated the ecological flow required for the downstream section of the Seomjingang Dam, which is known as the habitat of the endangered Acheilognathus somjinensis, in order to secure the river flow of the Seomjingang Dam. For this purpose, the proper discharge was calculated using the PHABSIM model, which is a hydrological survey and physical habitat simulation method, and the proper discharge of other fish species were also comprehensively reviewed. As a result of this study, the current river maintenance flow at the Seomjingang Dam partially satisfies the ecological maintenance flow including the Acheilognathus somjinensis in the downstream section of the Seomjingang Dam. However, this is recognized as the minimum discharge to maintain the ecology in the downstream section of the Seomjingang Dam, and it would be more desirable to secure larger river maintenance flow than this. This study can contribute the determination of the river maintenance flow of the Seomjingang Dam by proposing the river maintenance flow considering the fish habitat environment in the river.

• 한국수자원학회논문집
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• 제52권spc2호
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• pp.811-822
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• 2019

본 연구에서는 용담댐 하류, 원주천댐, 홍천강을 대상으로 환경생태유량을 산정하였으며, 멸종위기종 및 국내고유종을 고려한 대상어종으로 용담댐 하류는 감돌고기, 원주천댐은 쉬리, 홍천강은 묵납자루를 선정하여 각 하천에서 환경생태유량을 산정하였다. 환경생태유량을 산정을 위한 물리서식처 분석은 수리모형과 서식처 모형이 결합된 Physical Habitat Simulation (PHABSIM)과 RIVER2D를 적용하여 수행하였다. 생태 환경 모니터링을 통해 연구 대상지별 대상종의 서식처 적합도 지수를 Instream Flow and Aquatic Systems Group (IFASG) 방법을 적용하여 성장단계별 서식처 작합도 지수를 산정하였다. 특히 어류 모니터링 성과를 바탕으로 대상종의 성장단계별 서식처 적합도 지수를 산정하였다. PHABSIM을 활용한 분석 결과, 조절 하천인 용담댐하류에서 산란기에는 $4.9m^3/s$, 치어기 $5.8m^3/s$, 성어기에는 $8.9m^3/s$에서 가중가용면적이 최대인 최적 환경생태유량이었다. 원주천댐에서는 쉬리의 산란기에는 $0.4m^3/s$, 치어기에는 $1.0m^3/s$, 그리고 성어기에는 $1.5m^3/s$의 최적 환경생태유량을 나타내었다. 또한 비조절하천인 홍천강에서는 묵납자루의 산란기 $5m^3/s$, 치어기 $4m^3/s$, 그리고 성어기에는 $6m^3/s$의 최적 환경생태유량이 산정되었다.

• 국제초고층학회논문집
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• 제1권2호
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• pp.81-85
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• 2012

Vertical meteorological conditions encountered by super tall buildings, such as wind speed, temperature and humidity, vary due to their height. Therefore, it is necessary to consider these environmental changes to properly estimate the heating and cooling loads, and to minimize the energy demands for HVAC in super tall buildings. This paper aims to analyze how vertical meteorological changes affect heating and cooling loads of super tall buildings by using numerical simulation. A radiosonde, which observes atmospheric parameters of upper air such as wind speed, wind direction, temperature, relative humidity and pressure, was used to provide weather data for the building load simulation. A hypothetical super tall building was used for the simulation to provide quantified characteristics of the heating and cooling loads, comparing the lower, middle and upper parts of the building. The effect of weather data on the heating and cooling loads in super tall building was also discussed.

• 한국수자원학회논문집
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• 제46권6호
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• pp.629-642
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• 2013

본 연구에서는 낙동강 본류의 강정고령보에 설치된 인공하도식 어도의 효율성을 2차원 물리서식처 모형인 River2D를 이용하여 평가해 보았다. 강정고령보 상하류단의 실측 수위를 이용하여 모형을 보정 및 검정하였다. 모의조건은 2012년 풍수량, 평수량, 저수량을 기준으로 어도 입구 및 어도 내부의 흐름장을 분석하였다. 특히 본 연구의 목표종인 피라미가 산란기인 봄철에 주로 이동을 하므로, 저수기를 기준으로 어도가 기능을 잘 유지하는지 살펴보았다. 분석결과, 풍수 및 평수기에는 본류 수위가 높아 어도로의 피라미 유입 효율성이 떨어져 보였다. 반면 저수기에는 본류의 낮은 수위로 인해 어도 입구에 상대적으로 적절한 유속이 발생하여 유입효율과 이동효율이 높아질 것으로 평가되었다. 어도 내 흐름은 어류가 소상하기에 무리가 없는 유속장이 발생하는 것으로 파악되었다.

• 국제초고층학회논문집
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• 제11권3호
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• pp.227-240
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• 2022

Under the Korean Enforcement Decree of the Building Act, all high story apartment houses more than 5 stories high are mandated to install a fire evacuation system to ensure safe evacuation from fire accidents and providing quick and easy bidirectional escape route when main entrance is blocked by flame or toxic smoke. However, the current fire evacuation system shows a lack of understanding from residents and thus is widely ignored for having insufficient safety functions, especially vis-à-vis fire emergencies. Studies have found that an alternative evacuation method, the escapable fire evacuation system, has been analyzed for safety evaluation compared with the conventional passive fire escape system and can bring efficient and safer solutions, providing high rise residents escape from fire accidents. Evaluation for safety evacuation has been performed by the Fire Dynamics Simulation and applying Pathfinder simulation. This resulted in providing appropriate escape routes within the safety escape time and allowed for people in high rise building fires to get to safety.

• 대한환경공학회지
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• 제38권2호
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• pp.47-55
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• 2016

본 연구에서는 유량점증방법론에 입각하여 물리 서식처 모의 시스템의 기반을 둔 2차원 수리 및 서식처 모의인 River2D를 적용하였다. 대상 지점은 전주천 상류부이며, 수리모의 결과에 대한 비교는 갈수량 조건에서 검정된 HEC-RAS 수리모의 결과를 바탕으로 River2D와 유속, 수심 모의 결과를 비교, 평가하였다. 그 결과 유속의 RMSE는 0.18, NSE는 0.71, 결정계수는 0.78이고, 수심의 RMSE는 0.02, NSE는 0.71, 결정계수는 0.73으로 수리모의 결과가 실측치에 잘 반영되는 것으로 평가된다. 서식처 적합도 지수를 구축하기 위해 선정한 대표 어종은 10년간 어류 모니터링을 통하여 가장 출현빈도가 높은 피라미, 쉬리 어종에 대하여 선정하였다. 또한 평수량, 조건에서의 서식처 적합도 지수를 바탕으로 가중가용면적-유량 관계곡선을 산출하였으며, 한강 및 금강 수계에서 적합도 지수를 구축한 강형식(2010)의 지수를 가지고 모의한 결과와 비교, 평가하였다. 생태유량 산정 결과 피라미는 $1.5{\sim}2.0m^3/s$ 쉬리는 $1.8{\sim}2.0m^3/s$으로 산정되었다. 대상유역의 수질, 하도 구성, 생물 다양성 등이 매우 양호한 생태이고, 모의 결과 값을 유황분석과 비교해볼 때, 산정된 어류별 생태유량은 전주천 상류부에 적합한 것으로 평가된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.28-28
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• 2023

Most countries worldwide are finding it difficult to make decisions regarding the utilization of water resources and the ecological flow protection of rivers because of serious water shortages and global climate warming. To overcome this difficulty, accurate ecological flow processes and protected ecological objectives are required. Since the introduction of the concept, ecological flow calculations have been developed for more than 60 years. This technical development has always been dominated by countries such as the United States, Australia, and the United Kingdom. The technical applications, however, vary substantially worldwide. Some countries, for instance, did not readjust the method because of a lack of understanding of the ecological effect or because they failed to achieve elaborate scheduling. Mostly, readjustments were not made because the users could not make their choices from among numerous methods for ecological flow. This paper presents three research results based on a systematic review of 240 methods with clear connotation boundaries. First, the ecological flow algorithm was developed along with the scientific and technological progress in the river ecosystem theory, ecohydrological relationship, and characterization and simulation of hydrological and hydrodynamic processes. In addition, the basis of the method has evolved from the hydrological process of the ecosystem, hydraulics-habitat conditions, and social development interference to whole ecosystem simulation. Second, 240 methods were classified into 50 sub-categories to evaluate their advantages and disadvantages according to the ecological flow algorithms of hydrology, hydraulics, habitat, and other comprehensive methods. According to this evaluation, 60% of the methods were not suitable for further application, including the method based on the percentage of natural runoff. Furthermore, the applicability of the remaining methods was presented according to the evaluation based on the aspects of allocation of water resources, water conservancy project scheduling, and river ecological evaluation. Third, In the future, most developing countries should strengthen the guarantee of high-standard ecological flow via a coordination mechanism for the ecological flow guarantee established under a sustainable framework or via an ecological protection pattern at the national level according to the national system. Concurrently, a reliable ecological flow demand process should also be established on the basis of detailed investigation and research on the relationship between river habitats, ecological hydrology, and ecological hydraulics. This will ensure that the real-time evaluation of ecological flow forces the water conservancy project scheduling and accurate allocation of water.

• 국제초고층학회논문집
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• 제8권4호
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• pp.255-264
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• 2019

This paper describes large eddy simulation of wind pressures on a square cylinder in a uniform flow and a high-rise building immersed in an atmospheric turbulent boundary layer. For the atmospheric boundary layer case, the inflow turbulence is generated by a numerical wind tunnel. In the numerical simulation, particular attention is devoted to the performance of an auto hexahedral non-structural mesh. Both simulations are performed for three grid systems: an auto hexahedral non-structured grid, a structured Cartesian grid and a non-structured triangular prism grid, and for three grid numbers. The present study shows that the auto hexahedral unstructured mesh achieves the best simulation results for wind pressures on the square cylinder and the high-rise building. When the grid number is sufficiently large, the differences among the results obtained from the three investigated grid systems are not significant. However, the advantage of the auto hexahedral unstructured mesh becomes clear when the grid number decreases, because it enables a balanced distribution of orthogonal grids. The results described in this paper demonstrate that the auto hexahedral non-structured mesh has good potential applicability to simulation of urban flows.

• 환경영향평가
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• 제20권3호
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• pp.367-379
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• 2011

This study was conducted to develop an ecological park planning model to enhance the functions of habitats and ecological corridors in Green Belt Areas, because changing policies have resulted in the degredation of the Green Belts due to progressive fragmentation of ecosystems. The principal outcome of the study is to plan an ecological park model through the restoration of habitats. In order to evaluate the capacity of the model to enhance the ecological functions of habitats and ecological corridors in Green Belt Areas, a simulation of habitats was carried out in the Sungnam-Yusoo region. The model was developed via following steps: 1. Selection of candidate sites and selection of the study site by analyzing development factors; 2. Selection of target species that can represent the habitat at the site; 3. Analysis of the site's suitability index for the target species; 4. Establishment of a conceptual plan to enhance and expand the currently produced suitability index; 5. Creation of a master plan based on the conceptual plan; and 6. Evaluation of the enhanced and expanded suitability index of the site. The study showed that the Habitat Unit (HU) of Rana coreana, which was selected as the target species of the study, increased from $28,044m^2$(3.6%) to $224,352m^2$(28.8%), and the HU of the site as the ecological corridor for wild animals increased from $4,674m^2$(0.6%) to $152,684m^2$(19.6%). The study results show that the ecological deficits of the Green Belt Area can be overcome by enhancing the ecological functions of the region, which should be beneficial. The model could be utilized for effective enhancement and management of other Green Belt Areas.