• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.95-105
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• 2021

Drought is a disaster that causes prolonged and wide scale damage. Recently, the severity and frequency of drought occurrences, and drought damage have been increased significantly due to climate change. As a result, a quantitative study of drought factors is needed to better understand and prevent future droughts. In the case of agricultural drought, several existing studies examine the economic damage caused by droughts and their causes, but these studies are not well suited to estimating crop-oriented agricultural drought damage and the factors that absolutely affect agricultural drought. This study determines which factors most affect agricultural drought. It examines meteorological factors and those related to agricultural water supplied by irrigation facilities. Rice paddy production per unit area is lower than the average from the last two years where agricultural drought occurred. We compare the relative frequency of agricultural drought impacts with irrigation facilities, effective reservoir storage, the number of water supply facilities, and the meteorological drought index such as Standardized Precipitation Index (SPI). To identify factors that affect agricultural drought, we correlate rice paddy production anomalies with irrigation water supply for the past two years. There was a high positive correlation between rice paddy production and irrigation water usage, and there was a low or moderate negative correlation between rice paddy production anomalies compared to the average of the past two years and SPI. As a result, agricultural water supply by irrigation facilities was judged to be more influential than meteorological factors in rice paddy production. This study is expected to help local governments establish policies related to agricultural drought response.

• Journal of Wetlands Research
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• v.11 no.2
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• pp.77-87
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• 2009

Drought has different characteristics from other disasters. Say, drought effect can be prolonged according to drought duration and so the estimation of drought damage can be difficult. Therefore this study suggested and applied the proper drought damage estimation method developed based on previous methods. The suggested method was used for the drought damage estimations considering agricultural aspect and domestic water use which the data are available. We estimated drought damages on Gimhae-si, Namhae-gun, Uiryeong-gun, Changnyeong-gun, and Changwon-si in Gyungsang Nam-do from 2006 to 2008. As a result, in agricultural aspect, the damage on rice was about 195million won in Uiryeong-gun and on rice was about 67million won in Changnyeong-gun. In domestic water use, the damage was about 21billion won on 4 towns of Namhae-gun when we assumed the expense for sufferance is 400,000 won. We may need develope the method in the direction of the best use of present data for the improvement of the suggested method in agricultural aspect. In the case of the estimation of drought damage about domestic water use, we could suggest more realistic method if we consider the weights for the expense for sufferance and water use.

• The Journal of Engineering Geology
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• v.33 no.2
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• pp.241-256
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• 2023

Long-term droughts and frequent spring droughts are causing damage to crops, which are the means of livelihood of residents of the Yeoncheon region. To analyze the degree of drought in Yeoncheon, the ratio of monthly precipitation and discharge was reviewed through observed data, and the standardized precipitation index and streamflow drought index were calculated. As a result of drought analysis using precipitation and discharge observation stations near the Yeoncheon basin, it was analyzed that the drought that occurred in 2014 was common to all drought indices and that drought occurred continuously until 2019, either large or small. In the case of drought indices with a duration of 12 months, it is expected that the damage caused by the drought would be severe as the drought period lasted 24 months. In order to manage drought damage, it is important to understand and predict the current state of drought. In order to cope with drought in advance, it is urgent to implement an integrated operation management strategy for rivers and waterworks structures according to the degree and duration of drought.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.5
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• pp.1-11
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• 2021

Soil moisture plays a critical role in hydrological processes, land-atmosphere interactions and climate variability. It can limit vegetation growth as well as infiltration of rainfall and therefore very important for agriculture sector and food protection. Recently, due to the increased damage from drought caused by climate change, there is a frequent occurrence of shortage of agricultural water, making it difficult to supply and manage stable agricultural water. Efficient water management is necessary to reduce drought damage, and soil moisture management is important in case of upland crops. In this study, soil moisture was calculated based on the water balance model, and the suitability of soil moisture data was verified through the application. The regional soil moisture was calculated based on the meteorological data collected by the meteorological station, and applied the Runs theory. We analyzed the spatiotemporal variability of soil moisture and drought impacts, and analyzed the correlation between actual drought impacts and drought damage through correlation analysis of Standardized Precipitation Index (SPI). The soil moisture steadily decreased and increased until the rainy season, while the drought size steadily increased and decreased until the rainy season. The regional magnitude of the drought was large in Gyeonggi-do and Gyeongsang-do, and in winter, severe drought occurred in areas of Gangwon-do. As a result of comparative analysis with actual drought events, it was confirmed that there is a high correlation with SPI by each time scale drought events with a correlation coefficient.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.3
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• pp.3-15
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• 2008

North Korea is one of the vulnerable countries facing the threat of a drought, so that it is unavoidable to experience fatal damage when drought is occurred, and it is necessary to improve the drought response capability of water resources systems. However, it is still difficult to find research efforts for drought characteristics and drought management in North Korea. This study is to quantify drought duration and magnitude and to analyze drought characteristics in North Korea. In order to quantitatively identify historical drought conditions and to evaluate their variability, drought indices are commonly used. In this study, drought indices including dry-day index, deciles of normal precipitation, Phillips drought index, standardized precipitation index and Palmer drought severity index are calculated and compared monthly using the weather data for the twenty one meteorological stations in North Korea. The indices compared with the drought damage records that have reported from 1990 to present to understand how the indices can explain the drought. A comparative study was also conducted to evaluate the relative severity of the significant droughts occurred during 2000 and 2001 which were reported as the worst drought in North Korea. Drought indices calculated from this study demonstrated that those can be the effective tools in quantitatively evaluating drought severity and measures of drought. Thus it is recommended the distributed trend of drought be considered when the plan or measures for drought in North Korea are established.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.21-28
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• 2017

The main goal of this paper is to assess application of UAV (Unmanned Aerial Vehicle) remote sensing and GIS based images in detection and measuring of rice field drought area in South Korea. Drought is recurring feature of the climatic events, which often hit South Korea, bringing significant water shortages, local economic losses and adverse social consequences. This paper describes the assesment of the near-realtime drought damage monitoring and reporting system for the agricultural drought region. The system is being developed using drought-related vegetation characteristics, which are derived from UAV remote sensing data. The study area is $3.07km^2$ of Wonbuk-myeon, Taean-gun, Chungnam in South Korea. UAV images were acquired three times from July 4 to October 29, 2015. Three images of the same test site have been analysed by object-based image classification technique. Drought damaged paddy rices reached $754,362m^2$, which is 47.1 %. The NongHyeop Agricultural Damage Insurance accepted agricultural land of 4.6 % ($34,932m^2$). For paddy rices by UAV investigation, the drought monitoring and crop productivity was effective in improving drought assessment method.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.180-180
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• 2017

최근 기후변화에 따른 기상이변으로 전 세계적으로 가뭄피해가 증가하고 있다. 기존의 가뭄지수들은 자연현상만을 분석하여 가뭄의 심화정도를 나타내고 있다. 하지만 도시개발에 따른 도시화가 진행됨에 따라 인문 사회적 요소들이 서로 얽혀서 결합되어 단순히 자연현상만으로는 가뭄재해를 표현하기 어려워지고 있다. 본 연구에서는 복원력개념을 고려한 사회경제적 가뭄지수를 개발하고자 하였다. 복원력개념을 도입하기 위해서 가뭄위험지수, 가뭄대응능력 지수, 가뭄취약성 지수를 산정하였다. 가뭄위험지수로는 SDI(Streamflow Drought Index)를 사용하였으며, 사회 경제적 가뭄을 판단하기 위해서 적합 가뭄지속기간을 고려하였다. 대응능력 지표로는 인문, 사회적 요소와 생활, 농업, 공업용수 공급량, 지하수 함양량을 고려하였다. 취약성 지표로는 인문 사회적 요소와 생활, 농업용수 부족량, 기상요소를 고려하였다. 각 요소의 가중치는 AHP분석을 통해 산정하였다. 산정된 SDI(Streamflow Drought Index), 가뭄대응능력지수, 가뭄취약성지수를 표준화하여 잠재가뭄피해지수 PDDI(Potential Drought Damage Index)를 산정하였으며, 실제 가뭄 기간을 참고하여 등급화를 실시하였다. 그 후, 단순강우를 고려한 SPI(Standardized Precipitation Index)와 강우와 증발산량을을 고려한 RDI(Recommaissamce Drought Index)와의 비교를 통하여 복원력 개념을 고려한 잠재가뭄피해지수의 필요성을 확인하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3B
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• pp.243-252
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• 2011

The change of rainfall pattern due to recent climate change increases the occurrence probability of drought in Korea. Unlike other natural disasters, a drought has long duration, extensive area subject to damage, and greater socioeconomic damage than other disasters. In order to evaluate drought severity, meteorological drought indices are mainly used in practice. This study presents a more realistic method to evaluate drought severity considering drought climate factors as well as socioeconomic factors which are vulnerable to disaster. To perform a spatial evaluation of drought risk in Gyeongsang-do, drought risk was defined and analyzed through the hazard index and the vulnerability index. The drought hazard index was spatially assessed using the drought index and GIS. The drought vulnerability index was also spatially assessed using the 5 socioeconomic factors. As a result, the drought risks were compared and used for evaluating regional drought risk considering regional characteristics of Gyeongsang-do.

• Journal of Korean Society of Rural Planning
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• v.28 no.4
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• pp.93-104
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• 2022

Agriculture is one of the most vulnerable sector to droughts, and drought damage on the agriculture sector could have effects on other sector. Droughts have different characteristics compared to other extreme events, which means more sophisticated methods considering the characteristics of droughts are required when measuring their damage. The purpose of this study is to analyze the damage of droughts based on limited computational general equilibrium model. To be specific, we constructed a CGE model focusing on the agriculture sector in Korea. Also, to limit changes in land use and labor, we limited them, and assume droughts only have effects on productivity of value-added. Lastly, we simulate drought effects on rice production in Korea based on several climate scenarios and GCM to identify the economic effects of droughts. The results show that 1) the cumulated damage of droughts during 2021~2040 is higher than other periods (2040~2061, 2081~2100), 2) the correlation between the damage of droughts and SSP scenarios is insignificant. This result implies the necessity of the effective drought risk management to prevent future droughts effects, irrespective of mitigation policies. 3) Due to increases in rice price, GDP of rice sector is increased. However, GDP of the other sector and consumer welfare are decreased. This result show that indirect effects of droughts would be more important when measuring drought effects on agriculture sector.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.815-831
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• 2021

Drought forecasting is crucial to minimize the damage to food security and water resources caused by drought. Satellite-based drought research has been conducted since 1980s, which includes drought monitoring, assessment, and prediction. Unlike numerous studies on drought monitoring and assessment for the past few decades, satellite-based drought forecasting has gained popularity in recent years. For successful drought forecasting, it is necessary to carefully identify the relationships between drought factors and drought conditions by drought type and lead time. This paper aims to provide an overview of recent research trends and challenges for satellite-based drought forecasts focusing on lead times. Based on the recent literature survey during the past decade, the satellite-based drought forecasting studies were divided into three groups by lead time (i.e., short-term, sub-seasonal, and seasonal) and reviewed with the characteristics of the predictors (i.e., drought factors) and predictands (i.e., drought indices). Then, three major challenges-difficulty in model generalization, model resolution and feature selection, and saturation of forecasting skill improvement-were discussed, which led to provide several future research directions of satellite-based drought forecasting.