• Korean Journal of Agricultural Science
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• v.43 no.2
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• pp.205-214
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• 2016

A drought-tolerant transgenic rice (Agb0103) was developed using a pepper methionine sulfoxide reductase (CaMsrB2) under the control of rice Rab21 promoter with a selection marker, the phosphinothricin acetyltransferase (PAT) gene. Commercialization of genetically modified (GM) crops will require the evaluation of risks associated with the release of GM crops. With the potential problems associated to GM crops safety testing, the investigation of their effects on non-target organisms is necessary for environmental risk research. This study was carried out to assess acute toxicity of a GM crop using the water flea (Daphnia magna) for non-target organism risk evaluation. The effect of acute toxicity on Daphnia magna of Agb0103 rice and a non-GM rice, Ilmibyeo, were investigated at different concentrations (0, 625, 1,250, 2,500, 5,000, and 10,000 mg/L). The Agb0103 rice used for the test was confirmed to express the CaMsrB2/PAT gene by the PCR and ELISA. Daphnia magna feeding tests showed no significant differences in cumulative immobility or abnormal response with either Agb0103 rice or non-GM rice. The 48hr-EC50 values showed no difference between Agb0103 rice (2243 mg/L) and non-GM rice (2694 mg/L). These results suggest that there is no significant difference in toxicity to Daphnia magna between Agb0103 rice and its non-GM counterpart.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.1
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• pp.64-79
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• 2016

The purpose of this study is to find the relationship between precipitation deficit, SPI(standardized precipitation index)-12 month, agricultural reservoir water storage deficit and agricultural drought-related big data, and to evaluate the usefulness of agricultural risk management through big data. For the long term drought (from January 2014 to September 2015), each data was collected and analysed with monthly and Provincial base. The minimum SPI-12 and maximum reservoir water storage deficit compared to normal year were occurred at the same time of July 2014, and August and September 2015. The maximum frequency of big data was occurred at June and July of 2014, and March and June to September of 2015. The maximum big data was occurred 1 month advanced in 2014 and 2 months advanced in 2015 than the maximum reservoir water storage deficit. The occurrence of big data was sensitive to spring drought from March, late Jangma of June, dry Jangma of July and the rainfall deficit of September 2015. The big data was closely related with the meteorological drought and agricultural drought. Because the big data is the in situ feeling drought, it is proved as a useful indicator for agricultural risk management.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.1
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• pp.21-29
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• 2019

This study analyzed the variability of drought risk based on trend analysis of dry-seasonal dam inflow located in upper river basins. To this, we used areal averaged precipitation and dam inflow of three upper river dams such as Soyang dam, Chungju dam, and Andong dam. We employed Mann-Kendall trend analysis and change point detection method to identify the significant trends and changing point in time series. Our results showed that significant decreasing trends (95% confidence interval) in dry-seasonal runoff rates (= dam inflow/precipitation) in three-dam basins. We investigated potential causes of decreasing runoff rates trends using changes in potential evapotranspiration (PET) and precipitation indices. However, there were no clear relation among changes in runoff rates, PET, and precipitation indices. Runoff rate reduction in the three dams may increase the risk of dam operational management and long-term water resource planning. Therefore, it will be necessary to perform a multilateral analysis to better understand decreasing runoff rates.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.3
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• pp.309-319
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• 2023

Recently, the frequency and intensity of meteorological disasters have increased due to climate change. In South Korea, there are regional differences in vulnerability and response capability to cope with climate change because of regional climate characteristics. In particular, drought results from various factors and is linked to extensive meteorological, hydrological, and agricultural impacts. Therefore, in order to effectively cope with drought, it is necessary to use a composite drought index that can take into account various factors, and to evaluate future droughts comprehensively considering climate change. This study evaluated hydrologic risk(${\bar{R}}$) of future drought in the Nakdong River basin based on the Dynamic Naive Bayesian Classification (DNBC)-based composite drought index, which was calculated by applying Standardized Precipitation Index (SPI), Streamflow Drought Index (SDI), Evaporate Stress Index (ESI) and Water Supply Capacity Index (WSCI) to the DNBC. The indices used in the DNBC were calculated using observation data and climate scenario data. A bivariate frequency analysis was performed for the severity and duration of the composite drought. Then using the estimated bivariate return periods, hydrologic risks of drought were calculated for observation and future periods. The overall results indicated that there were the highest risks during the future period (2021-2040) (${\bar{R}}$=0.572), and Miryang River (#2021) had the highest risk (${\bar{R}}$=0.940) on average. The hydrologic risk of the Nakdong River basin will increase highly in the near future (2021-2040). During the far future (2041-2099), the hydrologic risk decreased in the northern basins, and increased in the southern basins.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.1
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• pp.37-45
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• 2015

Recent droughts in South Korea have had large economic and environmental impacts across the country. Changes in rainfall and hydrologic patterns due to climate change can potentially increase the occurrence of extreme droughts and affect the future availability of water resources. Therefore, it is necessary to evaluate drought vulnerability for water resources planning and management, and identify the appropriate mitigation actions to conduct a drought risk analysis in the context of climate change. The objective of this study is changes in the temporal trends of drought characteristics in South Korea to examine drought impacts under climate change. First, the changes of drought occurrence were analyzed by applying the Standardized Precipitation Evapotranspiration Index (SPEI) for meteorological data on 54 meteorological stations, and were analyzed for the past 30 years (1981-2010), and Representative Concentration Pathways (RCP) climate change scenarios (2011-2100). Second, the changes on the temporal trends of drought characteristics were performed using run theory, which was used to compare drought duration, severity, and magnitude to allow for quantitative evaluations under past and future climate conditions. These results show the high influence of climate change on drought phenomenon, and will contribute to water resources management and drought countermeasures to climate change.

• Journal of Environmental Science International
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• v.29 no.11
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• pp.1099-1108
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• 2020

In this study, the capacity of supplying agricultural water to 13 districts was analyzed by calculating the necessary water supply for the arable land of Gunwi-gun and examining the capacity of supplying water to reservoirs, streams, pumping stations, collection sites, and groundwater wells in Gunwi-gun. As a result, among the 13 districts the second district was found to be short of water by 1.2×10⁶ tons/year. In general, local governments establish drought measures by selecting drought disaster risk zones. While selecting drought-risk areas, some water-poor areas that do not have water sources should be selected, even if the entire area has a sufficient water supply. The water-supply evaluation at the regional level was insufficient for locating areas without water sources, but most areas with water sources, such as streams, reservoirs, and pumping stations, were found to have no shortage of water. To locate water shortage areas without water sources, GIS analysis conducted a field survey of areas with a distance of 4 or less than that of water sources analyzed by GIS analysis. Sixty-nine sites in 13 districts were selected for the on-site survey and six areas of water shortage were identified in areas other than the second district.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.2
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• pp.29-36
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• 2017

The objective of this study was to analyze the temporal and spatial characteristics of agricultural drought by tracking the daily reservoir storage in Chungnam province. All daily records of the percent of reservoir storage from 2000 to 2015 were collected for 130 irrigation reservoirs from the RIMS (Rural Infrastructure Management System). The temporal change of province-wide average reservoir storage and the statistics showed that the annual average and minimum percent of reservoir storage in 2015 were extremely low like as those in the historical drought years of 2001 and 2012. The minimum reservoir storage on record was a 41 % at the end of September and remained far less than its historical average even until the end of the year. Furthermore, the annual average reservoir storage (68.3 %) recorded the lowest on record since 2000. In addition, about half of 130 major irrigation reservoirs in Chungnam fell into the risk of water shortage below 30 % full, and, in terms of annual minimum reservoir storage, the 79 reservoirs yielded lower storage in 2015 comparing with the measured in another drought year, 2001. On the other hand, irrigation reservoirs of comparatively worse storage condition revealed to be mostly located on the inside, such as Cheongyang-gun and Hongsung-gun. Conclusively, the low reservoir storage, still far below average even on December 2015, induced a serious concern about that more extreme drought would happen in the next spring.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6B
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• pp.561-569
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• 2010

In this study, the impact of climate change on extreme drought events is investigated by comparing drought severity-area-duration curves under present and future climate. The depth-area-duration analysis for characterizing an extreme precipitation event provides a basis for analysing drought events when storm depth is replaced by an appropriate measure of drought severity. In our climate-change impact experiments, the future monthly precipitation time series is based on a KMA regional climate model which has a $27km{\times}27km$ spatial resolution, and the drought severity is computed using the standardized precipitation index. As a result, agricultural drought risk is likely to increase especially in short duration, while hydrologic drought risk will greatly increase in all durations. Such results indicate that a climate change vulnerability assessment for present water resources supply system is urgent.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.54-58
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• 2014

Climate change may result in greater risk of yield reduction of waxy corn due to drought stress and maize is one of the sensitive crops to the soil moisture shortage. While irrigation is the most effective practice to reduce the drought damage, farmers are unable to apply water due to limited water resource and irrigating facilities. The study was conducted to investigate the application effect of salicylic acid and abscisic acid on reducing drought stress of waxy corn (Zea mays L.). Drought stress was imposed by withholding irrigation from 9 days before anthesis to 14 days after anthesis. Salicylic acid or abscisic acid was applied on tasseling date at concentration of 0.5 mM and 0.1 mM, respectively. Drought stress increased anthesis-silking interval (ASI) by 3.0~3.3 days and decreased plant height, ear length, ear diameter, number of rows in ear, and yield by 47~51 cm, 4.6~5.0 cm, 4.4~5.3 mm, 1.5~2.0, and 2.4~2.5 Mg/ha, respectively. Application of salicylic acid and abscisic acid did not significantly reduced the drought injuries of waxy corn. Pretreatment of the plant growth regulators before water deficit stress or divided application at low concentration may be required to obtain the reduction effect on drought stress of waxy corn.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.147-147
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• 2020