• 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.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.178-178
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• 2017

기후변화 및 지구온난화로 인하여 가뭄의 피해가 증가하는 현상을 보이고 있다. 본 연구는 연구유역인 청미천 유역을 대상으로 하여 유지유량 확보를 위한 수자원관리 사업의 효과를 분석하였다. 분석방법은 청미천 유역의 원부, 용평, 성호조절지에 용수를 공급하는 사업이 설치 전후로, 원부교 지점에서의 유지유량인 0.96 m s을 만족하는 일수의 변화에 대하여 평가하였다. 평가기 간은 1986년부터 2015년과 RCP 4.5 & 8.5 시나리오(2011년~2100년)에 대해 평가하였다. 이때, 평가를 위한 하천유량은 SWAT(Soil and Water Assessment Tool) 모형을 이용하여 모의한 결과를 토대로 산정하였다. 평가 결과 과거의 경우 사업 적용 전에는 0.96을 만족하지 못하는 일수가 전체대비 15.3%였지만 사업적용 후에는 12.73%로 2.56% 감소하였다. RCP 4.5의 경우 2011년부터 2040년은 2.77%가, 2041년부터 2070년은 2.65%, 2071년부터 2100년은 3.95%가 감소함을 확인 하였다. RCP 4.5의 경우 점점 감소율이 증가하는 추세였지만, RCP 8.5는 2011년부터 2040년은 2.95%, 2041년부터 2070년은 2.58%, 2071년부터 2100년은 2.39%의 구간별 부족일수 감소율을 보이고 있다. RCP 8.5의 경우는 RCP 4.5와 반대로 미래로 갈수록 부족일수 감소율이 점점 감소하는 추세를 보이고 있다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.2
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• pp.65-73
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• 2016

We estimated the averaged maximum incidences of bacterial canker at suitable sites for kiwifruit cultivation in 2020s and 2050s using D-PSA-K model with RCP4.5 and RCP8.5 climate change scenarios. Though there was a little difference between the estimation using RCP4.5 and that using RCP8.5, the estimated maximum disease incidences were more than 75% at all the suitable sites in Korea except for some southern coastal areas and Jeju island under the assumption that there are a plenty of infections to cause the symptoms. We also analyzed the intermediate and final outputs of D-PSA-K model to find out the trends on the change in disease incidence affected by climate change. Whereas increase of damage to kiwifruit canes in a non-frozen environment caused by bacterial canker was estimated at almost all the suitable sites in both the climate change scenarios, rate of necrosis increase caused by the bacterial canker pathogen in a frozen environment during the last overwintering season was predicted to be reduced at almost all the suitable sites in both the climate change scenarios. Directions of change in estimated maximum incidence varied with sites and scenarios. Whereas the maximum disease incidence at 3.14% of suitable sites for kiwifruit cultivation in 2020s under RCP4.5 scenario was estimated to increase by 10% or more in 2050s, the maximum disease incidence at 25.41% of the suitable sites under RCP8.5 scenario was estimated so.

• Journal of Korea Water Resources Association
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• v.51 no.2
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• pp.141-150
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• 2018

The purpose of this study is to evaluate the future hydrologic behavior affected by the potential climate and land use changes in upstream of Anseong-cheon watershed ($366.5km^2$) using SWAT. The HadGEM3-RA RCP 4.5 and 8.5 scenarios were used for 2030s (2020-2039) and 2050s (2040-2059) periods as the future climate change scenario. It was shown that maximum changes of precipitation ranged from -5.7% in 2030s to +18.5% in 2050s for RCP 4.5 scenarios and the temperature increased up to $1.8^{\circ}C$ and $2.6^{\circ}C$ in 2030s RCP 4.5 and 2050s 8.5 scenarios respectively based on baseline (1976-2005) period. The future land uses were predicted using the CLUE-s model by establishing logistic regression equation. The 2050 urban area were predicted to increase of 58.6% (29.0 to $46.0km^2$). The SWAT was calibrated and verified using 14 years (2002-2015) of daily streamflow with 0.86 and 0.76 Nash-Sutcliffe model efficiency (NSE) for stream flow (Q) and low flow 1/Q respectively focusing on 2 drought years (2014-2015) calibration. For future climate change only, the stream discharge showed maximum decrease of 24.2% in 2030s RCP 4.5 and turned to maximum increase of 10.9% in 2050s RCP 4.5 scenario compared with the baseline period stream discharge of 601.0 mm by the precipitation variation and gradual temperature increase. While considering both future climate and land use change, the stream discharge showed maximum decrease of 14.9% in 2030s RCP 4.5 and maximum increase of 19.5% in 2050s RCP 4.5 scenario by the urban growth and the related land use changes. The results supported that the future land use factor might be considered especially for having high potential urban growth within a watershed in the future climate change assessment.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.5
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• pp.37-48
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• 2013

The objective of this study is to assess the impact of potential climate change on the hydrological components, especially on the streamflow, evapotranspiration and snowmelt, by using the Soil Water Assessment Tool (SWAT) for 17 Hanriver middle watersheds of South Korea. For future assessment, the SWAT model was calibrated in multiple sites using 4 years (2006-2009) and validated by using 2 years (2010-2011) daily observed data. For the model validation, the Nash-Sutcliffe model efficiency (NSE) for streamflow were 0.30-0.75. By applying the future scenarios predicted five future time periods Baseline (1992-2011), 2040s (2021-2040), 2060s (2041-2060), 2080s (2061-2080) and 2100s (2081-2100) to SWAT model, the 17 middle watersheds hydrological components of evapotranspiration, streamflow and snowmelt were evaluated. For the future precipitation and temperature of RCP 4.5 scenario increased 41.7 mm (2100s), $+3^{\circ}C$ conditions, the future streamflow showed +32.5 % (2040s), +24.8 % (2060s), +50.5 % (2080s) and +55.0 % (2100s). For the precipitation and temperature of RCP 8.5 scenario increased 63.9 mm (2100s), $+5.8^{\circ}C$ conditions, the future streamflow showed +35.5 % (2040s), +68.9 % (2060s), +58.0 % (2080s) and +63.6 % (2100s). To determine the impact on snowmelt for Hanriver middle watersheds, snowmelt parameters of SWAT model were determined through evaluating observed streamflow data during snowmelt periods (November-April). The results showed that average SMR (snowmelt / runoff) of 17 Hanriver middle watersheds was 62.0 % (Baseline). The annual average SMR were 42.0 % (2040s), 39.8 % (2060s), 29.4 % (2080s) and 27.9 % (2100s) by applying RCP 4.5 scenario. Also, the annual average SMR by applying RCP 8.5 scenario were 40.1 % (2040s), 29.4 % (2060s), 18.3 % (2080s) and 12.7 % (2100s).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.561-568
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• 2019

Recently, Korea has suffered from severe droughts due to climate change. Therefore, we need to pay attention to the change of drought risk to develop appropriate drought mitigation measures. In this study, we investigated the changes of hydrologic risk of extreme drought using the current observed data and the projected data according to the RCP 4.5 and 8.5 climate change scenarios. The bivariate frequency analysis was performed for the paired data of drought duration and severity extracted by the threshold level method and by eliminating pooling and minor droughts. Based on the hydrologic risk of extreme drought events Jeonbuk showed the highest risk and increased by 51 % than the past for the RCP 4.5 scenario, while Gangwon showed the highest risk and increased by 47 % than the past for the RCP 8.5 scenario.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.2
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• pp.53-62
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• 2013

Land-use/cover changes not only amplify or alleviate influence of climate changes but also they are representative factors to affect environmental change along with climate changes. Thus, the use of land-use/cover changes scenario, consistent climate change scenario is very important to evaluate reliable influences by climate change. The purpose for this study is to predict and analyze the future urban growth considering social and economic scenario from RCP scenario suggested by the 5th evaluation report of IPCC. This study sets land-use/cover changes scenario based on storyline from RCP 4.5 and 8.5 scenario. Urban growth rate for each scenario is calculated by urban area per person and GDP for the last 25 years and regression formula based on double logarithmic model. In addition, the urban demand is predicted by the future population and GDP suggested by the government. This predicted demand is spatially distributed by the urban growth probability map made by logistic regression. As a result, the accuracy of urban growth probability map is appeared to be 89.3~90.3% high and the prediction accuracy for RCP 4.5 showed higher value than that of RCP 8.5. Urban areas from 2020 to 2050 showed consistent growth while the rate of increasing urban areas for RCP 8.5 scenario showed higher value than that of RCP 4.5 scenario. Increase of urban areas is predicted by the fact that famlands are damaged. Especially RCP 8.5 scenario indicated more increase not only farmland but also forest than RCP 4.5 scenario. In addition, the decrease of farmland and forest showed higher level from metropolitan cities than province cities. The results of this study is believed to be used for basic data to clarify complex two-way effects quantitatively for future climate change, land-use/cover changes.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.578-578
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• 2015

동아시아 지역의 대부분은 몬순의 영향으로 인해 수자원의 계절적 변동성이 크며 이로 인해 홍수 및 가뭄이 빈번하게 발생하고 있다. 기후변화에 따른 기온과 강수량의 변화는 수자원의 변동성을 더욱 악화시킬 수 있으며, 수재해 피해를 더욱 가중시킬 것으로 전망되고 있다. 본 연구에서는 기후변화에 따른 동아시아 지역의 기온 및 강수량의 변화를 전망하고, 그 특성을 분석하고자 한다. 이를 위해 CMIP5의 핵심실험인 2개 RCP시나리오(RCP4.5, RCP8.5)에 대한 다수의 GCMs 결과를 이용하였다. 구축한 기후시나리오를 이중선형보간법(bilinear interpolation)을 이용하여 공간적으로 상세화하였으며, Delta method를 이용하여 편의보정을 수행하였다. GCM 모의자료의 편의를 산정하기 위해 관측자료는 APHRODITE의 기온 및 강수량 자료를 이용하였다. GCM에 따라 차이가 나지만, 우리나라의 경우 평균적으로 100~300mm 정도 과소모의 되는 것으로 나타났다. 미래 기온 및 강수량 전망을 위해 과거기간은 1976~2005년, 미래기간은 2021~2050년(2040s), 2061~2090년(2070s)으로 구분하였다. 우리나라의 경우 RCP 4.5 하에서 연평균기온은 $1.4{\sim}1.7^{\circ}C$(2040s), $2.2{\sim}3.4^{\circ}C$(2070s) 정도 상승할 것으로 나타났으며, 연평균 강수량은 4.6~5.3% (2040s), 8.4~10.5% (2070s) 정도 증가할 것으로 나타났다. RCP 8.5에서는 연평균 기온은 RCP4.5에 비해 상승폭이 더 컸으며, 강수량은 유사한 결과가 나타났다. 또한, 동아시아 지역에서도 연평균 기온이 상승하고 연평균 강수량은 증가하는 것으로 나타났다. 다만, 지역별로 계절별 기온 및 강수량이 매우 다른 양상으로 나타났다. 이는 동아시아 지역과 같이 계절별 강수량 발생패턴이 다른 지역에서는 홍수 및 가뭄에 매우 중요한 역할을 할 것이다. 따라서 지역적으로 계절별 강수량의 변화를 분석해야 할 것으로 판단되며, 추후 유출량 모의를 기반으로 홍수 및 가뭄의 영향을 직접적으로 분석해야할 것으로 판단된다.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1117-1126
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• 2018

Water supply system aims to meet the user's demand by securing water resources in a stable way. However, water supply failure sometimes happens because inflow decreases during drought period. Droughts induced by the lack of precipitation do not always lead to water supply failures. Thus, it is necessary to consider features of actual water shortage event when we evaluate a water supply risk. In this study, we developed a new drought index for drought management, i.e., Joint Drought Management Index (JDMI), using two water supply system performance indices such as reliability and vulnerability. Future data that were estimated from GCMs according to RCP 4.5 and 8.5 scenarios were used to estimate future water supply risk. After dividing the future period into three parts, the risk of water supply failure in the Nakdong River basin was analyzed using the JDMI. As a result, the risk was higher with the RCP 4.5 than the RCP 8.5. In case of RCP 4.5, W18 (Namgangdam) was identified as the most vulnerable area, whereas in case of RCP 8.5, W23 (Hyeongsangang) and W33 (Nakdonggangnamhae) were identified as the most vulnerable area.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.185-196
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• 2015

A conceptual watershed model HSPF (Hydrological Simulation Program-Fortran) was applied to the Hwangryong river watershed to evaluate climate change effects on pollution loads of the river. For modeling purposes, the Hwangryong river watershed was divided into 7 sub-watersheds. The model was calibrated and validated for the river discharges against the data observed in 2011 at several monitoring stations. The RCP scenarios were set up for the model simulations after being corrected by change factor method. The simulation results of the RCP 4.5 scenario indicate that the annual river discharge and concentrations of BOD, TN, TP of the Hwangryong river will continually increase during the second-half of the 21st century. As for the RCP 8.5 scenario, the simulations results imply that the pollution loads will increase during the middle of the 21st century reflecting the pattern of precipitation. Monthly distributions of the pollution loads for the RCP 4.5 and the RCP 8.5 scenarios show it will increase the most in September and February, respectively.