• 물과 미래
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• 제35권5호
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• pp.31-43
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• 2002

본 연구에서는 온난화에 의한 하천유역의 수문응답(강우유출, 특히 일단위의 유황)의 변화양상을 수치실험을 통해 정량적으로 평가하였다. 이산화탄소 농도의 증가에 따른 온난화의 진행으로 야기되는 수문학적 평가는 많은 관측자료를 필요로 하며 이를 정량적으로 평가한다는 것은 대단히 어려운 일이다. 따라서 장래의 기후를 예측하는 수단으로서 적정한 시나리오를 상정하여 평하는 방법을 생각할 수 있다. 본 연구에서는 여러 가지 상정할 수 있는 시나리오 중 기온은 $0^{\circ}C$에서 $4.0^{\circ}C$까지 변화하며 강수량은 15%까지 증감할 수 있다는 시나리오를 상정하여 불확실성이 큰 지구온난화의 문제에 대하여 간단하면서 명확한 가정을 도입하였다. 따라서, 대상유역인 안동댐 유역에 대한 장래의 하천유량은 기후변화 시나리오에서 야기되는 강수량을 발생시켜 탱크모형에 의하여 일 유량을 모의 발생하게 된다. 본 연구에서는 2030년을 이산화탄소 농도가 배증되는 시점 ($2{\times}CO2$), 2010년, 2020년 및 2050년을 각각 ($1.5{\times}CO2$),($1.75{\times}CO2$) 및 ($2.5{\times}CO2$)로 설정하였으며, 이 시기에 대한 하천 유황의 해석 및 온난화가 발생되지 않았을 때와의 비교 검토를 실시하였다.

• 한국수자원학회논문집
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• 제56권11호
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• pp.765-774
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• 2023

기후변화로 인해 강우의 변동성이 증가하여가뭄 또는 홍수가 빈번하게 발생하고 있다. 불확실성이 증가하는 기후 조건에 대응하는 수자원 시설 관리대책의 수립을 위해서는, 하천의 자연 유출량과 인공계 물공급을 모두 고려한 저수지 운영 모의를 통하여, 이수 및 치수 측면의 수자원 시설 영향에 대한 종합적인 분석이 선행되어야 한다. 본 연구에서는 강우-유출과 저수지 운영 모형을 연계 모의하여, 합천댐 유역을 대상으로 기후변화에 대한 이수안전도 및 홍수위험도 분석을 수행하였다. 강우-유출모형으로는 modèledu Génie Rural à 4 paramètres Journalier (GR4J) 모형을, 저수지운영 모형은 HEC-Ressim 모형의 구조를 가지는 R 기반모형을 적용하였다. 구축된 연계 모형에 기후변화 시나리오를 2100년까지적용하여 합천댐의 이수안전도 및 홍수위험도 변화를 정량적으로 분석하였다. 이수안전도 분석 결과, SSP5-8.5에 비해 SSP2-4.5 조건에서 이수안전도가 더높으며, 먼미래로 갈수록 모두 과거 조건보다 이수안전도가 증가하는 것으로 나타났다. 특히, 먼미래 기간에서는 홍수 위험도의 범위가 더욱 넓어지는 것으로나타났으며, SSP2-4.5와 SSP5-8.5 두 시나리오모두 먼미래 기간에서 홍수 위험도의 중앙값이 가장 높았다. 또한, 연총강수량과연총유출은 과거 대비 10% 미만 증가하는데 비해, 홍수시댐무효방류량은 120%이상 증가하여, 연구대상지역인 합천댐유역의 경우, 미래 기후변화로 인한 홍수위험도가 상승할 것으로 예상된다.

• 대기
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• 제30권4호
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• pp.377-390
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• 2020

Not only emissions, but also atmospheric circulation is a key factor that affects local particulate matters (PM) concentrations in Korea through ventilation effects and transboundary transports. As part of the atmospheric circulation, air stagnation especially adversely affects local air quality due to weak ventilation. This study investigates the large-scale circulation related to air stagnation over Korea during winter and projects the climate change impacts on atmospheric patterns, using observed PM data, reanalysis and regional climate projections from HadGEM3-RA with Modified Korea Particulate matter Index. Results show that the stagnation affects the PM concentration, accompanied by pressure ridge at upper troposphere and weaken zonal pressure gradient at lower troposphere. Downscaling using HadGEM3-RA is found to yield Added-Value in the simulated low tropospheric winds. For projection of future stagnation, SSP5-8.5 and SSP1-2.6 (high and low emission) scenarios are used here. It has been found that the stagnation condition occurs more frequently by 11% under SSP5-8.5 and by 5% under SSP1-2.6 than in present-day climate and is most affected by changes in surface wind speed. The increase in the stagnation conditions is related to anticyclonic circulation anomaly at upper troposphere and weaken meridional pressure gradient at lower troposphere. Considering that the present East Asian winter monsoon is mainly affected by change in zonal pressure gradient, it is worth paying attention to this change in the meridional gradient. Our results suggest that future warming condition increase the frequency of air stagnation over Korea during winter with response of atmospheric circulation and its nonlinearity.

• 한국기후변화학회지
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• 제5권4호
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• pp.277-284
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• 2014

Biochar application to soil is widely known to have effects of climate change mitigation and soil quality improvement. However, effects of biochar on soil ecosystem are not always positive and some biochars are reported to contain toxic materials which might influence soil ecosystem. In this context, this study aims to investigate behavioral changes of earthworms(Eisenia fetida, Eisenia andrei) in response to different application rates of biochar to artificial soil. Treatment included two types of biochars made from rice husk (RH_Char) and wastewater sludge (SL_Char) with 1% and 10% application rates, respectively. Avoidance test revealed that earthworms did not avoid SL_Char treatments at 1% and 10%, while they rather moved to the RH_Char treatments probably due to higher labile carbon content(Hot water extractable carbon) of the RH_Char. The HWC content of RH_Char was 4 times higher than that of the SL_Char. Results of reproduction test showed that the survival rates, number of juveniles and number of cocoons were not influenced by biochar application except for the treatment of SL_Char at 10% rate. In the SL_Char 10% treatment, fatality was approximately 3.3 times as high as the control and the number of cocoons was 1.3 times higher in the same treatment than the control, indicating that earthworms were under environmental stress. The possible explanation for the stress condition was related to higher Cd, Ni, Cr, and As contents in the SL_Char. Overall results imply that biochar application at low rate might not change earthworms' behavior for the short term, while the reproduction behavior might be negatively influenced under the high application rate.

• Smart Structures and Systems
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• 제26권3호
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• pp.277-290
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• 2020

Disasters, including earthquakes and landslides, have enormous economic and social losses besides their impact on environmental disruption. Iran, and particularly its Western part, is known as an earthquake susceptible area due to numerous strong ground motions. Studying ecological changes due to climate change can improve the public and expert sector's awareness and response to future disastrous events. Synthetic Aperture Radar (SAR) data and Interferometric Synthetic Aperture Radar (InSAR) technologies are appropriate tools for modeling and surface deformation modeling. This paper proposes an efficient approach to detect ground deformation changes using Sentinel-1A. The focal point of this research is to map the ground surface deformation modeling is presented using InSAR technology over Sarpol-e Zahab on 25^th November 2018 as a study case. For surface deformation modeling and detection of the ground movement due to earthquake SARPROZ in MATLAB programming language is used and discussed. Results show that there is a general ground movement due to the Sarpol-e Zahab earthquake between -7 millimeter to +18 millimeter in the study area. This research verified previous researches on the advanced image analysis techniques employed for mapping ground movement, where InSAR provides a reliable tool for assisting engineers and the decision-maker in choosing proper policies in a time of disasters. Based on the result, 574 out of 682 damaged buildings and infrastructures due to the 2017 Sarpol-e Zahab earthquake have moved from -2 to +17 mm due to the 2018 earthquake with a magnitude of 6.3 Richter. Results show that mountainous areas have suffered land subsidence, where urban areas had land uplift.

• 대기
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• 제28권2호
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• pp.175-185
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• 2018

Characteristics of precipitation response to enhanced aerosols have been investigated during the severe haze events observed in Korea for 2011 to 2016. All 6-years haze events are classified into long-range transported haze (LH: 31%), urban haze (UH: 28%), and yellow sand (YS: 18%) in order. Long-range transported one is mainly discussed in this study. Interestingly, both LH (68%) and YS (87%) appear to be more frequently accompanied with precipitation than UH (48%). We also found out the different timing of precipitation for LH and YS, respectively. The variations of precipitation frequency for the LH event tend to coincide with aerosol variations specifically in terms of temporal covariation, which is in contrast with YS. Increased aerosol loadings following precipitation for the YS event seems to be primarily controlled by large scale synoptic forcing. Meanwhile, aerosols for the LH event may be closely associated with precipitation longevity through changes in cloud microphysics such that enhanced aerosols can increase smaller cloud droplets and further extend light precipitation at weaker rate. Notably, precipitation persisted longer than operational weather forecast not considering detailed aerosol-cloud interactions, but the timescale was limited within a day. This result demonstrates active interactions between aerosols and meteorology such as probable modifications of cloud microphysics and precipitation, synoptic-induced dust transport, and precipitation-scavenging in Korea. Understanding of aerosol potential effect on precipitation will contribute to improving the performance of numerical weather model especially in terms of precipitation timing and location.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.467-467
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• 2015

Sustainable water resource management requires the assessment of hydrological variability in response to climate fluctuations and anthropogenic activities. Determining quantitative estimates of water balance and total basin discharge are of utmost importance to understand the variations within a basin. Hard-to-reach areas with few infrastructures, coupled with lengthy administrative procedures makes in-situ data collection and water management processes very difficult and unreliable. In this study, the hydrological behavior of Lake Chad whose extent, extreme climatic and environmental conditions make it difficult to collect field observations was examined. During a 10 year period [January 2003 to December 2013], dataset from space-borne and global hydrological models observations were analyzed. Terrestial water storage (TWS) data retrieved from Gravity Recovery and Climate Experiment (GRACE), lake level variations from Satellite altimetry, water fluxes and soil moisture from Global Land Data Assimilation System (GLDAS) were used for this study. Furthermore, we combined altimetry lake volume with TWS over the lake drainage basin to estimate groundwater and soil moisture variations. This will be validated with groundwater estimates from WaterGAP Global Hydrology Model (WGHM) outputs. TWS showed similar variation patterns Lake water level as expected. The TWS in the basin area is governed by the lake's surface water. As expected, rainfall from GLDAS precedes GRACE TWS with a phase lag of about 1 month. Estimates of groundwater and soil moisture content volume changes derived by combining altimetric Lake Volume with TWS over the drainage basin are ongoing. Results obtained shall be compared with WaterGap Hydrology Model (WGHM) groundwater estimate outputs.

• 한국농림기상학회지
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• 제25권4호
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• pp.346-358
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• 2023

기후변화가 심화됨에 따라 작물에 미치는 영향을 평가하고 개선 방안을 도출하는 것은 필수적이다. 본 연구에서는 고온, 고이산화탄소 조건에서 벼의 질소 흡수 반응 및 질소이용효율 등을 분석하여 기후변화에 따른 벼의 적응 대책을 검토하고자 수행하였다. 21C 후반 RCP8.5 시나리오에 근거하여 온도는 2001~2010년 대비 +4.7 ℃ 상승, CO₂는 800 ppm을 기후변화 조건으로 하였으며, 질소를 0, 9, 18 kg 10a^-1 수준으로 각각 시비하였다. 그리고 벼 낱알의 질소 흡수를 보기 위해 수비 시비시 안정동위원소¹⁵N-urea를 표층 시비하였다. 기후변화 조건에서는 현재 기후 대비 잎, 줄기의 바이오매스량은 증가하나 등숙률 감소로 정조중이 38 % 감소하여 수확지수도 47% 감소하였다. 기후변화로 인해 잎과 줄기에서 질소흡수량은 현재기후 대비 각각 87%, 139% 증가하였으며, 반대로 곡실의 질소함량은 31% 감소하는 경향을 보였다. 기후변화 조건에서 ANUE, NUEg는 표준시비 시 각각 76%, 54% 유의하게 감소하였으며, 수비 질소의 흡수량과 회수율(RE)도 이와 동일한 경향을 보였으며 질소시비를 증가하였을 경우에도 동일한 경향을 보였다. 임실 및 등숙률 저하로 sink/source 균형이 무너져 질소 화합물 및 광합성 산물의 이동이 저하되어 질소함량이 영양생장기관에 머물러있고 곡실로의 전류가 되지 않으므로 향후 이를 극복할 수 있는 고온 적응 품종 육성과 이앙시기 조절 등이 선행되어야 한다.

• 자원환경지질
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• 제36권6호
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• pp.545-556
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• 2003

영산강 하구 퇴적물에서 최종빙기 및 현세에 해당하는 길이 18.9m의 시추 퇴적물(심도 20.5∼l.6m)을 획득하였으며, 퇴적물의 조직과 유기질 미화석 분석을 통하여 고환경의 변화를 인지하였다. AMS$^{14}$C 연대측정과 한반도에서의 화분분대 대비에 의하여 퇴적물 연대를 결정하였다. 본 시추 퇴적물에서는 크게 3가지 고환경대를 구분할 수 있었다. (1)최종빙기 퇴적물:주로 하천 퇴적층이며 고토양화 되어 있다. 퇴적 작용과 토양화 작용을 수차례에 걸쳐 받은 것으로 보이며, 고토양의 양상으로 보아 한랭$.$습윤 환경에서 토양화 작용이 진행된 것으로 추측할 수 있다. (2) 현세 초기∼중기 퇴적물:해수면 상승으로 인하여 해수의 영향을 받게 되었으며, 해양성 미화석을 다량 포함하는 점토로 구성된다. (3) 현세 후기 퇴적물: 보다 한랭한 기후를 나타낸다. 이러한 양상은 지역적, 전지구적 환경변화 양상과 일치하는 결과를 보인다.

• Journal of Forest and Environmental Science
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• 제33권2호
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• pp.122-129
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• 2017

Understanding how future climate conditions will be impact on the biodiversity and species composition is important, because biodiversity becomes more important in environment assessment. To understand the biological changes including diversity and species composition over time (temporal variation within a year), the species diversity and composition of ground beetles were investigated in two well-preserved areas in the Sobaeksan National Park using pitfall traps. In addition, relationships between ground beetles and environmental variables were studied by considering temporal variation. We collected 2,146 ground beetle specimens representing 45 species, and individual-based rarefaction curves indicated that similar species richness was found between Geumseon Valley (GV) and Namcheon Valley (NV). The Bray-Curtis matrix comparisons between study sites were characterized by similar ground beetles sample heterogeneity, while temporal variations in abundance, species richness, and ${\beta}-diversity$ of ground beetles showed rather difference over time according to location of study sites. In GV site, minimum temperature was selected as the best predictor for abundance, species richness, and ${\beta}-diversity$ of ground beetles, while those relationships in NV site were more complicated. In conclusion, our study suggests that understanding the different response of ground beetles to climatic variables related to local habitat conditions is important to predict the effect of climate change on biological communities.