• Journal of Wetlands Research
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• v.15 no.4
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• pp.595-607
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• 2013

In this study we estimated ETCCDI and frequency based precipitation using observed precipitation and precipitation from Representative Concentration Pathway(RCP) scenarios for 58 weather stations which have the recorded data more than 30 years. We tried to eliminate the bias by Quantile Mapping and tested for outliers of simulated data under climate change scenario. Then we estimated ETCCDI related to precipitation and frequency based precipitation for the future. In addition to this study examined the changes of frequency based precipitation for the future target periods. According to the result, dry days will be increased in Korean Peninsula in the 2090s. Also it showed that the number of heavy precipitation day more than 80mm/day tends to be increased in 3~7% in the future. The precipitation of 24-hour duration under climate change will be increased by 17.7% for 80-year frequency, 18.2% for 100-year frequency and 19.6% for 200-year frequency in 2090s. In the 21st century, the damage caused by natural disasters is expected to be increased due to increase of precipitation and the change of runoff characteristics under climate change. Therefore, the proposed ETCCDI and precipitation frequency under climate change are expected to be used for the future natural disaster plan.

• Journal of Korea Water Resources Association
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• v.46 no.6
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• pp.569-583
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• 2013

This study is to evaluate the future climate change impact on hydrological components in the Seolmacheon ($8.54km^2$) mixed forest catchment located in the northwest of South Korea using SWAT (Soil and Water Assessment Tool) model. To reduce the uncertainty, the model was spatially calibrated (2007~2008) and validated (2009~2010) using daily observed streamflow, evapotranspiration, and soil moisture data. Hydrological predicted values matched well with the observed values by showing coefficient of determination ($R^2$) from 0.74 to 0.91 for streamflow, from 0.56 to 0.71 for evapotranspiration, and from 0.45 to 0.71 for soil moisture. The HadGEM3-RA future weather data of Representative Concentration pathway (RCP) 4.5 and 8.5 scenarios of the IPCC (Intergovernmental Panel on Climate Change) AR5 (Assessment Report 5) were adopted for future assessment after bias correction of ground measured data. The future changes in annual temperature and precipitation showed an upward tendency from $0.9^{\circ}C$ to $4.2^{\circ}C$ and from 7.9% to 20.4% respectively. The future streamflow showed an increase from 0.6% to 15.7%, but runoff ratio showed a decrease from 3.8% to 5.4%. The future predicted evapotranspiration about precipitation increased from 4.1% to 6.8%, and the future soil moisture decreased from 4.3% to 5.5%.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.877-886
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• 2022

This study was carried out to analyze how the flow and water quality of the Sangsa Lake (juam control basin) change according to future climate change and what countermeasures are needed. Aquatic Ecosystem Model) was used in conjunction. As climate change scenarios, RCP (Representative Concentration Pathways) 4.5 and RCP 8.5 scenarios of AR5 (5th Assessment Report) according to the Intergovernmental Panel on Climate Change (IPCC) were used. For the climate change scenario, detailed data on the Sangsa Lake basin were used by the Korea Meteorological Administration, and after being evaluated as a correction and verification process for the 10-year period from 2012 to 2021, the present, 2025-2036, 2045- The summer period from June to August and the winter period from December to February were analyzed separately for each year by dividing it into 2056 and 2075-2086. RCP 8.5 was higher than RCP 4.5 as an arithmetic mean for the flow rate of the watershed of the superior lake for the entire simulation period, and TN and TP also showed a tendency to be higher at RCP 4.5. However, in RCP 8.5, the outflow of pollutants decreased during the dry season and the outflow of pollutants increased during the summer, indicating that the annual pollutant outflow was concentrated during the flood season, and it is analyzed that countermeasures are needed.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.3
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• pp.221-233
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• 2018

Two climate change scenarios, the RCP (Representative Concentration Pathways) 4.5 and the RCP 8.5 in the fifth Assessment Report (AR5) by Intergovernmental Panel on Climate Change (IPCC), were applied in the Yocheon basin area using the SWAT (Soil and Water Assessment Tool) model to estimate changes in flow rates and pollutant loadings in the future. Field stream flow rate data in Songdong station and water quality data in Yocheon-1 station between 2013~2015 were used for model calibration. While $R^2$ value of flow rate calibration was 0.85 and $R^2$ value of water qualities were in the 0.12~0.43 range. The total study period was divided into 4 sub periods as 2030s (2016~2040), 2050s (2041~2070) and 2080s (2071~2100). The predicted results of flow rates and water quality concentrations were compared with results in calibrated periods, 2015s (2013~2015). In both RCP scenarios, flow rate and TSS (Total Suspended Solid) loadings were estimated to be in increasing trend while TN (Total Nitrogen) and TP (Total Phosphorus) loadings showed decreasing patterns. Also, flow rates and pollutant loadings showed larger differences between the maximum and the minimum values in RCP 4.5 than RCP 8.5 scenarios indicating more severe effect of drought and flood, respectively. Dependent on simulation period and rainfall periods in a year, flow rate, TSS, TN and TP showed different trends in each scenario. This emphasizes importance of considerations on time and space when analyzing climate change impacts of each variable under various scenarios.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.409-417
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• 2018

This study elicited the necessity of considering regional climate change on Low Impact Development (LID) application by evaluating its effect on LID efficiency. The relationship between climate change factors and LID efficiency was evaluated with Representative Concentration Pathway (RCP) showing the increase of annual precipitation and representative evapotranspiration. Simply lowering lawn surface (LID3), a practical option to increase retention and infiltration effect, demonstrated hydrological improvement above two conventional options, bioretention with green roof (LID1) and bioretention only (LID2). High runoff reductions of applied options at RCP 4.5, supposing taking efforts for mitigating green house gases, revealed that climate change countermeasures were preferable to LID efficiencies. The increase of precipitation had more influence in hydrological change than that of reference evapotranspiration.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.516-516
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• 2016

기후변화는 농업생산량 감소와 식량 안보 문제와 같이 농업에 심각한 영향을 미칠 수 있다. 또한 기존의 농업수리 및 관개배수 시설 운영에 영향을 줄 수 있다. 따라서 지속가능한 농업 수자원 관리를 위해서는 기후변화의 영향을 고려한 장기적인 계획 수립이 필요하다. 따라서 본 연구에서는 논벼 지역의 설계용수량의 확률론적 분석을 통한 논벼 필요수량 및 설계용수량에 대한 기후변화영향 평가를 실시하였다. 이를 위해서 본 연구에서는 23개 GCM의 36개 산출물을 활용하여 Multi-model ensemble 구축하였다. 먼저 GCM별 증발산량과 유효우량을 산정한 결과 중부지역에서는 IPSL-CM5A 모델의 기후변화자료를 활용할 경우 증발산량과 유효우량이 타 GCM 모델들과 비하여 크게 산정되었다. 남부지역에서는 CanESM2 모델을 적용할 경우 가장 많은 증발산량과 유효우량이 모의되는 것으로 나타났다. 이처럼 GCM별로 다양한 결과가 모의되기 때문에 농업시설 설계에 적용되는 설계용수량의 경우 안전성을 위하여 Multi-GCM models을 활용할 필요가 있다. Multi-model ensemble의 RCP 4.5와 RCP 8.5 시나리오를 적용한 결과, 모든 경우에서 1995s(1981-2014)에 비해 설계용수량은 점차적으로 증가하는 것으로 나타났다. 평균 증가율은 RCP 4.5에서 중부지역이 9.4%, 남부지역이 6.0% 증가하는 것으로 나타난 반면, RCP 8.5에서는 중부지역이 11.1%, 남부지역이 8.2% 증가하는 것으로 나타났다. 또한 여러 GCM 산출물간의 불확실성은 RCP 4.5보다는 RCP 8.5 시나리오가, 중부 지역보다는 남부 지역이, 논벼 증발산량 보다는 유효우량이 더 큰 것으로 분석되었다. 본 연구는 향후 미래 가뭄 위험성을 최소화하기 위한 농업 수자원관리 전략수립에 활용될 수 있을 것이다. 또한 본 연구결과는 기후변화 영향 평가에 있어서 적합한 GCM 자료를 선택하는데 있어, 불확실성을 가늠할 수 있는 유용한 척도로 이용될 수 있을 것으로 기대된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.241-241
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• 2023

최근 수십 년 동안 전 세계의 거의 모든 하천 유역은 기후변화와 인간 활동에 의해 직간접적으로 영향을 받았다. 특히, 유역 유출량은 기후변화와 인간 활동의 상호작용으로 수자원 분야에서 문제가 되고 있다. 기후와 인간 활동에 의해 변화하는 환경에서 수자원을 효율적으로 관리하기 위해서 유출량의 변화를 이해하는 것은 매우 중요하다. 따라서, 본 연구에서는 낙동강 유역의 22개 중권역을 대상으로 과거 관측자료 및 미래 기후변화 시나리오의 유출량, 강수량, 기온, 잠재 증발산량 및 실제 증발산량 자료를 이용하여 기후변화와 인간 활동이 유출량에 미치는 영향을 정량적으로 분석하였다. 과거 관측자료를 분석할 경우, 기초자료인 유출량의 경향성 및 유의성을 검증하기 위해 비모수적 방법인 Mann-Kendall 검증을 수행하였으며, Pettitt method를 이용하여 변화 지점을 결정하여 기준기간과 사후기간으로 구분하였다. 또한 Budyko 가설 기반 기후 탄력성 접근법을 이용하여 기후변화와 인간 활동이 하천 유출량에 미치는 영향을 정량적으로 분리하였다. 미래 RCP 시나리오 자료를 분석할 경우에도 기간을 나누고 기후 탄력성 접근법을 이용하여 유출량의 영향을 평가하였다. 분석 결과, 기후변화와 인간 활동의 상대적 기여도는 중권역 간에도 다양하다는 것을 확인할 수 있었다. 미래의 유출량을 분석한 결과, 대부분의 유역에서 기후변화의 기여도는 RCP 4.5일 때에 비해 RCP 8.5에서 더 크게 상승한 것으로 나타났다. 과거 기간(1966~2020)에 대하여 미래 기간 (2062~2099)에 대한 분석에서 중권역 중 금호강(#2012)은 RCP 4.5에서는 22.4%, RCP 8.5에서는 39.8%로 RCP 8.5가 큰 것으로 나타났다.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.5
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• pp.35-41
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• 2012

The paddy rice consumptive use in the six plains of the Korean peninsula was projected with changing climate under the representative concentration pathway (RCP) scenarios. High resolution climate data for the baseline (1961-1990) was obtained from the International water management institute (IWMI) and future high resolution climate projection was obtained from the Korea Meteorological Administration. Reference evapotranspiration (ET) was calculated by using Hargreaves equation. The results of this study showed that the average annual mean temperature would increase persistently in the future. Temperatures were projected to increase more in RCP8.5 than those in RCP4.5 scenario. The rice consumptive use during the growing period was projected to increase slightly in the 2020s and then more significantly in the 2050s and 2080s. It showed higher values for RCP8.5 than for RCP4.5. The rice consumptive use after transplanting in the study areas would increase by 2.2 %, 5.1 % and 7.2 % for RCP4.5 and 3.0 %, 7.6 %, and 13.3 % for RCP8.5, in the 2020s, 2050s, and 2080s, respectively, from the baseline value of 534 mm. The results demonstrated the effects of climate change on rice consumptive use quite well, and can be used in the future agricultural water planning in the Korean peninsula.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.73-82
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• 2013

The main objective of this study was to evaluate Representative Concentration Pathways (RCP) scenarios-based flood risk at a Si-Gun level. A bias correction using a quantile mapping method with the Generalized Extreme Value (GEV) distribution was performed to correct future precipitation data provided by the Korea Meteorological Administration (KMA). A series of proxy variables including CN80 (Number of days over 80 mm) and CX3h (Maximum precipitation during 3-hr) etc. were used to carry out flood risk assessment. Indicators were normalized by a Z-score method and weighted by factors estimated by principal component analysis (PCA). Flood risk evaluation was conducted for the four different time periods, i.e. 1990s, 2025s, 2055s, and 2085s, which correspond to 1976~2005, 2011~2040, 2041~2070, and 2071~2100. The average flood risk indices based on RCP4.5 scenario were 0.08, 0.16, 0.22, and 0.13 for the corresponding periods in the order of time, which increased steadily up to 2055s period and decreased. The average indices based on RCP8.5 scenario were 0.08, 0.23, 0.11, and 0.21, which decreased in the 2055s period and then increased again. Considering the average index during entire period of the future, RCP8.5 scenario resulted in greater risk than RCP4.5 scenario.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.5
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• pp.267-275
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• 2013

This study projected the future ocean wave climate changes based on global climate change scenario using the coupled climate model HadGEM2-AO according to the emission scenarios and using regional wave model. Annual mean significant wave height (SWH) is linked closely to annual mean wind speed during the forthcoming 21st Century. Because annual mean speed decreased in the western North Pacific, annual mean SWH is projected to decrease in the future. The annual mean SWH decreases for the last 30 years of the 21st century relative to the period 1971-2000 are 2~7% for RCP4.5 and 4~11% for RCP8.5, respectively. Also, extreme SWH and wind speed are projected to decrease in the future. In terms of seasonal mean, winter extreme SWH shows similar trend with annual extreme SWH; however, that of summer shows large increasing tendency compared with current climate in the western North Pacific. Therefore, typhoon intensity in the future might be more severe in the future climate.