• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.195-195
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• 2016

Kon - Ha Thanh River basin is the largest and the most important river basin in Binh Dinh, a province in the South Central Coast of Vietnam. In the lower rivers, frequent flooding and inundation caused by heavy rains, upstream flood and or uncontrolled flood released from upstream reservoirs, are very serious, causing damage to agriculture, socio-economic activity, human livelihood, property and lives. The damage is expected to increase in the future as a result of climate change. An advanced flood warning system could provide achievable non-structural measures for reducing such damages. In this study, we applied a modelling system which intergrates a 1-D river flow model and a 2-D surface flow model for simulating hydrodynamic flows in the river system and floodplain inundation. In the model, exchange of flows between the river and surface floodplain is calculated through established links, which determine the overflow from river nodes to surface grids or vice versa. These occur due to overtopping or failure of the levee when water height surpasses levee height. A GIS based comprehensive raster database of different spatial data layers was prepared and used in the model that incorporated detailed information about urban terrain features like embankments, roads, bridges, culverts, etc. in the simulation. The model calibration and validation were made using observed data in some gauging stations and flood extents in the floodplain. This research serves as an example how advanced modelling combined with GIS data can be used to support the development of efficient strategies for flood emergency and evacuation but also for designing flood mitigation measures.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.265-265
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• 2019

기후변화로 의한 기온의 상승은 가뭄, 홍수와 같은 재해를 일으킬 뿐만 아니라 깊은 호수나 저수지와 같은 수자원에도 용존 산소, 물질, 영양소 및 식물플랑크톤의 수직적 분포 등과 같은 다양한 부분에 영향을 미친다. 본 연구의 목적은 SWAT, HEC-ResSim 및 CE-QUAL-W2(이하 W2)모델을 사용하여 미래의 기후 변화에 따른 소양호의 수온, 성층강도 및 열적 안정성의 변화를 장기 예측하고 그 영향을 평가하는데 있다. W2 모델의 보정은 2005 년부터 2015 년까지의 실측 과거 데이터를 이용하여 보정하였고 기후변화 시나리오는 IPCC의 AR5 RCP 4.5 시나리오를 사용하였다. 기후자료는 GCM 모델인 HadGEM2-AO 결과를 상세화하여 모의기간의 자료를 생성하였다. SWAT모델을 이용하여 모의기간인 2016 년부터 2070 년까지 일단위로 저수지 유입을 예측했으며 HEC-ResSim모델을 이용하여 소양강댐 저수지 운영 조건에 따라 저수지 방류량 및 수위 변화를 모의하였다. 수온 해석을 위해 W2를 적용하여 저수지의 장기간의 수온 변화를 예측하였다. 결과적으로 대기 온도는 $0.0279^{\circ}C/year$(p < 0.05) 상승할 것으로 예측되었으며, 동일기간 상층(수면으로부터 5m 깊이)과 하층 (바닥으로부터 5m 높이) 수온은 각각 $0.0191^{\circ}C$/년(p < 0.05) 및 $0.008^{\circ}C$/년(p < 0.05) 상승할 것으로 예측되었다. 모의된 수온을 계절별로 분석했을 때 상층수온은 여름철 가장 큰 폭으로 상승하였으며 하층의 경우 겨울철에 가장 큰 폭으로 상승하였다. 계절별 상-하층 수온의 차는 여름이 가장 컸으며, 겨울에 온도차가 가장 작았다. 또한 미래 온도의 상승에 따라, 소양호의 성층 강도가 강해지는 경향을 보였으며 상층 및 하층의 온도차 $5^{\circ}C$를 기준으로 성층이 형성되는 기간은 큰 변동이 없었으나 소멸되는 시점이 점점 늦어지는 추세를 보여 성층 형성 기간이 길어지는 것으로 나타났다. 저수지 표면의 수온 상승은 식물플랑크톤의 계절 성장률에 영향을 미쳤는데, 특정 조건에서 규조류는 최적 성장 범위를 벗어나는 고온 조건에서 성장속도가 감소하였으나 녹조류와 남조류의 출현 시기가 빨라지며 장기화될 것으로 예측되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.56-60
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• 2008

Increasing urban sprawl and climate changes have been causing unexpected high-intensity rainfall events. Thus there are needs to enhance conventional disaster management system for comprehensive actions to secure safety. Therefore long-term and comprehensive flood management plans need to be well established. Recently torrential snowfall are occurring frequently, causing have snow traffic jams on the road. To secure safety and on-time operation of the Bi-modal tram system, well-structured disaster management system capable of analyzing the urban flash flooding and snow pack melt/freezing due to unexpected rainfall event and snowfall are needed. To secure safety of the Bi-modal tram system due to torrential snowfall, the snow melt simulation capability was investigated. The snow accumulation and snow melt were measured to validate the SWMM snow melt component. It showed that there was a good agreement between measured snow melt data and the simulated ones. Therefore, the Bi-modal tram disaster management system will be able to predict snow melt reasonably well to secure safety of the Bi-modal tram system during the winter. The Bi-modal tram disaster management system can be used to identify top priority area for snow removal within the tram route in case of torrential snowfall to secure on-time operation of the tram. Also it can be used for detour route in the tram networks based on the disaster management system predicted data.

• 지구물리
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• 제9권2호
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• pp.135-145
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• 2006

미국 해양대기청의 CCM3 기후모델을 이용하여 마지막최대빙하기 (Last Glacial Maximum(LGM)의 기온 및 물. 이용된 수치모델의 수평해상도는 약 75 km로 비교적 상세한 기후 기작들이 표현된다. LGM 실험은 CLIMAP 프로젝트에서 복원된 표층해수가 경계조건으로 이용되었으며 , LGM에 낮았던 대기 이산화탄소농도(200 pm) 이 적용되었고, 대륙빙하를 포함한 LGM 지표지형이 표현되었다 . LGM 경계조건하에서 전구온도는 겨울철 6.1도 여름철 5.6도 그리고 연평균 6도정도 감소한 것으로 시뮬레이션 된다 . 표층 기온의 감소는 14% 감소하고 여름에 17% 그리고 연간 13% 감소한다. 하지만, 미국, 남부유럽, 동아프리카, 남아메리카 등은 겨울에 현재보다 더 습하게 나타나며 , 캐나다 와 중동 지방은 여름철에 습윤하게 시뮬레이션 된다 . 이런 결과들은 호수면 변화기록으로부터 복원한 고기후 프락시 물수지 자료들과도 대체로 잘 일치한다 . 전체적으로 고해상도 기후모델은 지상에서 나타나는 세부적인 특징들을 잘 재현해내고 있다 .

• 한국산림과학회지
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• 제110권3호
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• pp.453-461
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• 2021

기후변화 대응과 탄소중립 실현을 위해 산림 바이오매스의 에너지 이용은 중요한 과제이다. 이 연구의 목적은 목재칩 보일러를 주력으로 사용하는 산림에너지자립마을의 투자 타당성을 분석하고 시설의 지속적 운영을 위해 필요한 적정열 보조금 수준을 산출하는 데 있다. 분석을 위해 순현재가치법과 선택의 유연성을 고려한 콜옵션 가격결정모형을 이용하였다. 분석결과에 따르면, 현재와 같이 국비 50%를 지원하고 전력에만 REC를 인정하면 산림에너지자립마을의 순현재가치와 내부수익률은 모두 음(-)이며, 실물옵션 모형으로 평가한 투자가치도 0으로 나타났다. 따라서 에너지 시설의 지속적 가동을 위해 정부 보조금이 필요하다. 시뮬레이션을 통해 사업의 옵션가치를 0보다 크게 만드는 열보조금 수준을 도출하였는데, 최소 0.0248원/kcal으로 나타났다.

• 한국태양에너지학회 논문집
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• 제39권2호
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• pp.33-43
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• 2019

In this study, reflecting long-term climate characteristics, we analyzed electricity generation and generation characteristics of 3kWp PV system, which was semi-integrated with air duct behind. Using PVsyst as a simulation analysis tool, we inputted "National reference standard weather data" of 16 regions as a typical climatic data. The result is summarized as follows: First, the national average annual electricity generation was 1,312 kWh/kWp (StDev, ${\sigma}=71$). It was most abundant in Mokpo with 1,434 kWh/kWp, which was average 21% greater than the lowest with 1,165 kWh/kWp in Seoul and 1,197 kWh/kWp in Jeju. National average daily generating time based on STC was 3.6 hours (${\sigma}=0.43$), and that of Mokpo and Seoul was 3.9 and 3.2 hours respectively. Second, Jeju showed the great difference of annual monthly generation by month (annual average = 99.7 kWh/kWp, ${\sigma}=25.5$), while Jinju showed the smallest difference (annual average = 115.5 kWh/kWp, ${\sigma}=10.6$). Generation in Jeju was at the largest in April with 132.2 kWh/kWp, which was 2.3 times greater than the lowest 55.2 kWh/kWp in January. However, generation in Jinju was at the largest in March with 129.3 kWh/kWp, which was only 1.3 times greater than the lowest 101.1 kWh/kWp in June. Third, the annual average PR was the highest in Incheon with 85.8% and the lowest in Jeju with 83.2%. PR of Mokpo was 84.3%, which was lower than that of national average.

• 농업과학연구
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• 제48권3호
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• pp.515-526
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• 2021

The frequency of typhoons and torrential rainfalls has increased due to climate change, and the concurrent risk of breakage of dams and reservoirs has increased due to structural aging. To cope with the risk of dam breakage, a more accurate emergency action plan (EAP) must be established, and more advanced technology must be developed for the prediction of flooding. Hence, the present study proposes a method for establishing a more effective EAP by performing flood and inundation analyses using one- and two-dimensional models. The probable maximum flood (PMF) under the condition of probable maximum precipitation (PMP) was calculated for the target area, namely the Gyeong-cheon reservoir watershed. The breakage scenario of the Gyeong-cheon reservoir was then built up, and breakage simulations were conducted using the dam-break flood forecasting (DAMBRK) model. The results of the outflow analysis at the main locations were used as the basis for the one-dimensional (1D) and two-dimensional (2D) flood inundation analyses using the watershed modeling system (WMS) and the FLUvial Modeling ENgine (FLUMEN), respectively. The maximum inundation area between the Daehari-cheon confluence and the Naeseong-cheon location was compared for each model. The 1D flood inundation analysis gave an area of 21.3 km², and the 2D flood inundation analysis gave an area of 21.9 km². Although these results indicate an insignificant difference of 0.6 km² in the inundation area between the two models, it should be noted that one of the main locations (namely, the Yonggung-myeon Administrative and Welfare Center) was not inundated in the 1D (WMS) model but inundated in the 2D (FLUMEN) model.

• 한국물환경학회지
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• 제36권6호
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• pp.508-520
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• 2020

Dam reservoirs have been reported to contribute significantly to global carbon emissions, but unlike natural lakes, there is considerable uncertainty in calculating carbon emissions due to the complex of emission pathways. In particular, the method of calculating carbon dioxide (CO2) net atmospheric flux (NAF) based on a simple gas exchange theory from sporadic data has limitations in explaining the spatiotemporal variations in the CO2 flux in stratified reservoirs. This study was aimed to analyze the spatial and temporal CO2 distribution and mass balance in Daecheong Reservoir, located in the mid-latitude monsoon climate zone, by applying a two-dimensional hydrodynamic and water quality model (CE-QUAL-W2). Simulation results showed that the Daecheong Reservoir is a heterotrophic system in which CO2 is supersaturated as a whole and releases CO2 to the atmosphere. Spatially, CO2 emissions were greater in the lacustrine zone than in the riverine and transition zones. In terms of time, CO2 emissions changed dynamically according to the temporal stratification structure of the reservoir and temporal variations of algae biomass. CO2 emissions were greater at night than during the day and were seasonally greatest in winter. The CO2 NAF calculated by the CE-QUAL-W2 model and the gas exchange theory showed a similar range, but there was a difference in the point of occurrence of the peak value. The findings provide useful information to improve the quantification of CO2 emissions from reservoirs. In order to reduce the uncertainty in the estimation of reservoir carbon emissions, more precise monitoring in time and space is required.

• 대기
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• 제32권3호
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• pp.223-233
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• 2022

Recent studies have shown that Madden-Julian Oscillation (MJO) is modulated by Quasi-Biennial Oscillation (QBO) during the boreal winter; MJO becomes more active and predictable during the easterly phase of QBO (EQBO) than the westerly phase (WQBO). Despite growing evidences, climate models fail to capture the QBO-MJO connection. One of the possible reasons is a weak static stability change in the upper troposphere and lower stratosphere (UTLS) by neglecting QBO-induced ozone change in the model. Here, we investigate the possible impact of the ozone-radiative feedback in the tropical UTLS on the QBO-MJO connection by integrating the Global Seasonal Forecasting System 5 (GloSea5) model. A set of experiments is conducted by prescribing either the climatological ozone or the observed ozone at a given year for the EQBO-MJO event in January 2006. The realistic ozone improves the temperature simulation in the UTLS. However, its impacts on the MJO are not evident. The MJO phase and amplitude do not change much when the ozone is prescribed with observation. While it may suggest that the ozone-radiative feedback plays a rather minor role in the QBO-MJO connection, it could also result from model biases in UTLS temperature and not-well organized MJO in the model.

• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1135-1145
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• 2022

Due to increase in concerns related to the climate change, state-wide promotion of the carbon neutrality has been in progress thus far. Smart City could be one of the measures as the initiative to mitigate the missions process. The primary purpose of Smart City can be summarized to be maximization of the social net-beneift to be returned for the local citizens and derivation of the optimal pattern of the energy consumption could belong to one of the elements included in the net-benefit. Currently, the energy consumption by the buildings has been determined to be responsible for the greatest consumption among the sectors considered to be energy-intensive. Moreover, considering the fact that the consumption by operations of HVAC is responsible for nearly 40% in the commercial buildings, it is virtually not possible to optimize schedules for the energy consumption with considerable deliverables from the perspective of the urban planners. Thus, the methods to implement the optimal schedules for the HVAC commissioned with the OHUs were concluded to be the suitable candidate resources for the simulation by EnergyPlus capable of monitoring the thermal changes in each subject space in the present research.