• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.284-301
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• 2023

The changes in rice climatic yield potential (CYP) across the Korean Peninsula are evaluated based on the new climate change scenario produced by the National Institute of Agricultural Sciences with 18 ensemble members at 1 km resolution under a Shared Socioeconomic Pathway (SSP) and Representative Concentration Pathways (RCP) emission scenarios. To overcome the data availability, we utilize solar radiation f or CYP instead of sunshine duration which is relatively uncommon in the climate prediction f ield. The result show that maximum CYP(CYPmax) decreased, and the optimal heading date is progressively delayed under warmer temperature conditions compared to the current climate. This trend is particularly pronounced in the SSP5-85 scenario, indicating faster warming, except for the northeastern mountainous regions of North Korea. This shows the benef its of lower emission scenarios and pursuing more efforts to limit greenhouse gas emissions. On the other hand, the CYPmax shows a wide range of feasible futures, which shows inherent uncertainties in f uture climate projections and the risks when analyzing a single model or a small number of model results, highlighting the importance of the ensemble approach. The f indings of this study on changes in rice productivity and uncertainties in temperature and solar radiation during the 21st century, based on climate change scenarios, hold value as f undamental information for climate change adaptation efforts.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.3
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• pp.1-11
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• 2014

Recently, major cities in Korea are suffering from frequent urban flooding caused by heavy rainfall. Such urban flooding mainly occurs due to the limited design capacity of the current drainage network, which increases the vulnerability of the cities to cope with intense precipitation events brought about by climate change. In other words, it can be interpreted that runoff exceeding the design capacity of the drainage network and increased impervious surfaces in the urban cities can overburden the current drainage system and cause floods. The study presents the green roof as a sustainable solution for this issue, and suggests the pre-design using the LID controls model in SWMM to establish more specific flood prevention system. In order to conduct the computer simulation in connection with Korean climate, the study used the measured precipitation data from Cheonan Station of Korea Meteorological Administration (KMA) and the forecasted precipitation data from RCP 8.5 scenario. As a result, Extensive Green Roof System reduced the peak runoff by 53.5% with the past storm events and by 54.9% with the future storm events. The runoff efficiency was decreased to 4% and 7%. This results can be understood that Extensive Green Roof System works effectively in reducing the peak runoff instead of reducing the total stormwater runoff.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.77-87
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• 2014

The impacts of climate change on upland crops is great significance for water resource planning, estimating crop water demand and irrigation scheduling. The objective of this study is to predict upland crop evapotranspiration, effective rainfall and net irrigation requirement for upland under climate change, and changes in the temporal trends in South Korea. The changes in consumptive use and net irrigation requirement in the six upland crops, such as Soybeans, Maize, Potatoes, Red Peppers, Chinese Cabbage (spring and fall) were determined based on the soil moisture model using historical meteorological data and climate change data from the representative concentration pathway (RCP) scenarios. The results of this study showed that the average annual upland crop evapotranspiration and net irrigation requirement during the growing period for upland crops would increase persistently in the future, and were projected to increase more in RCP 8.5 than those in RCP 4.5 scenario, while effective rainfall decreased. This study is significant, as it provides baseline information on future plan of water resources management for upland crops related to climate variability and change.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.4
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• pp.99-110
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• 2020

The objective of this study is to analyze the trend of changes in the water circulation rates under climate change by adopting the concept of WCR defined by the Ministry of Environment. With the need for sound water circulation recovery, the MOE proposed the idea of WCR as (1-direct flow/precipitation). The guideline for calculating WCR suggests the SCS method, which is only suitable for short term rainfall events. However, climate change, which affects WCR significantly, is a global phenomenon and happens gradually over a long period. Therefore, long-term trends in WCRs should also be considered when analyzing changes in WCR due to climate change. RCP (Representative Concentration Pathway) 4.5 and 8.5 scenarios were used to simulate future runoff. SWAT (Soil and Water Assessment Tool) was run under the future daily data from GCMs (General Circulation Models) after the calibration. In 2085s, monthly WCR decreased by 4.2-9.9% and 3.3-8.7% in April and October. However, the WCR in the winter increased as the precipitation during the winter decreased compared to the baseline. In the aspect of yearly WCR, the value showed a decrease in most GCMs in the mid-long future. In particular, in the case of the RCP 8.5 scenario, the WCR reduced 2-3 times rapidly than the RCP 4.5 scenario. The WCR of 2055s did not significantly differ from the 2025s, but the value declined by 0.6-2.8% at 2085s.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1149-1159
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• 2018

This study aims to predict the future flood damage cost of 113 middle range watersheds using 26 GCM outputs, hourly maximum rainfall, 10-min maximum rainfall, number of days of 80 mm/day, daily rainfall maximum, annual rainfall amount, DEM, urbanization ratio, population density, asset density, road improvement ratio, river improvement ratio, drainage system improvement ratio, pumping capacity, detention basin capacity and previous flood damage costs. A constrained multiple linear regression model was used to construct the relationships between the flood damage cost and other variables. Future flood damage costs were estimated for different RCP scenarios such as 4.5 and 8.5. Results demonstrated that rainfall related factors such as annual rainfall amount, rainfall extremes etc. widely increase. It causes nationwide future flood damage cost increase. Especially the flood damage cost for Eastern part watersheds of Kangwondo and Namgang dam area may mainly increase.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.80-90
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• 2015

Variability of precipitation pattern and intensity are increasing due to the urbanization and industrialization which induce increasing impervious area and the climate change. Therefore, more severe urban inundation and flood damage will be occurred by localized heavy precipitation event in the future. In this study, we analyze the future frequency based precipitation under climate change based on the regional frequency analysis. The observed precipitation data from 58 stations provided by Korea Meteorological Administration(KMA) are collected and the data period is more than 30 years. Then the frequency based precipitation for the observed data by regional frequency analysis are estimated. In order to remove the bias from the simulated precipitation by RCP scenarios, the quantile mapping method and outlier test are used. The regional frequency analysis using L-moment method(Hosking and Wallis, 1997) is performed and the future frequency based precipitation for 80, 100, and 200 years of return period are estimated. As a result, future frequency based precipitation in South Korea will be increased by 25 to 27 percent. Especially the result for Jeju Island shows that the increasing rate will be higher than other areas. Severe heavy precipitation could be more and more frequently occurred in the future due to the climate change and the runoff characteristics will be also changed by urbanization, industrialization, and climate change. Therefore, we need prepare flood prevention measures for our flood safety in the future.

• 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.

• Atmosphere
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• v.22 no.2
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• pp.221-231
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• 2012

Representative Concentration Pathways (RCP) are the latest emission scenarios recommended to use for the fifth assessment report of Intergovernmental Panel on Climate Change. This study investigates the projection of extreme precipitation in South Korea during the forthcoming 21st Century using the generalized extreme value (GEV) analysis based on two different RCP conditions i.e., RCP 4.5 and 8.5. Maximum daily precipitation required for GEV analysis for RCP 4.5 and 8.5 are obtained from a high-resolution regional climate model forced by the corresponding global climate projections, which are produced within the CMIP5 framework. We found overall increase in frequency of extreme precipitation over South Korea in association with climate change. Particularly, daily extreme precipitation that has been occurred every 20 years in current climate (1980~2005) is likely to happen about every 4.3 and 3.4 years by the end of 21st Century (2070~2099) under the RCP 4.5 and 8.5 conditions, respectively.

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.14-28
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• 2020

Future climate change may affect the hydro-thermal and biogeochemical characteristics of dam reservoirs, the most important water resources in Korea. Thus, scientific projection of the impact of climate change on the reservoir environment, factoring uncertainties, is crucial for sustainable water use. The purpose of this study was to predict the future water temperature and stratification structure of the Soyanggang Reservoir in response to a total of 42 scenarios, combining two climate scenarios, seven GCM models, one surface runoff model, and three wind scenarios of hydrodynamic model, and to quantify the uncertainty of each modeling step and scenario. Although there are differences depending on the scenarios, the annual reservoir water temperature tended to rise steadily. In the RCP 4.5 and 8.5 scenarios, the upper water temperature is expected to rise by 0.029 ℃ (±0.012)/year and 0.048 ℃ (±0.014)/year, respectively. These rise rates are correspond to 88.1 % and 85.7 % of the air temperature rise rate. Meanwhile, the lower water temperature is expected to rise by 0.016 ℃ (±0.009)/year and 0.027 ℃ (±0.010)/year, respectively, which is approximately 48.6 % and 46.3 % of the air temperature rise rate. Additionally, as the water temperatures rises, the stratification strength of the reservoir is expected to be stronger, and the number of days when the temperature difference between the upper and lower layers exceeds 5 ℃ increases in the future. As a result of uncertainty quantification, the uncertainty of the GCM models showed the highest contribution with 55.8 %, followed by 30.8 % RCP scenario, and 12.8 % W2 model.

• Journal of Korea Water Resources Association
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• v.50 no.10
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• pp.703-714
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• 2017

This paper analyzes the impact of two climate change scenarios on flow rate and water quality of the Yongdam Dam and its basin using CE-QUAL-W2 and SWAT, respectively. Under RCP 4.5 and RCP 8.5 scenarios by IPCC, simulations were performed for 2016~2095, and the results were rearranged into three separate periods; 2016~2035, 2036~2065 and 2066~2095. Also, the result of each year was divided as dry season (May~Oct) and wet season (Nov~Apr) to account for rainfall effect. For total simulation period, arithmetic average of flow rate and TSS (Total Suspended Solid) and TP (Total Phosphorus) were greater for RCP 4.5 than those of RCP 8.5, whereas TN (Total Nitrogen) showed contrary results. However, when averaged within three periods and rainfall conditions the tendencies were different from each other. As the scenarios went on, the number of rainfall days has decreased and the rainfall intensities have increased. These resulted in waste load discharge from the basin being decreased during the dry period and it being increased in the wet period. The results of SWAT model were used as boundary conditions of CE-QUAL-W2 model to predict water level and water quality changes in the Yongdam Dam. TSS and TP tend to increase during summer periods when rainfalls are higher, while TN shows the opposite pattern due to its weak absorption to particulate materials. Therefore, the climate change impact must be carefully analyzed when temporal and spatial conditions of study area are considered, and water quantity and water quality management alternatives must be case specific.