• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1166-1171
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• 2006

Drought is defined by differently for the several scientific and technical fields such as hydrological drought, agricultural drought, meteorological drought, climatological drought, atmospheric drought. A lot of drought indices have been developed to quantify drought severity levels. However these drought indices might be expressed differently as the drought conditions for specific period because the drought severity level is using different types of data on each condition. It is necessary for development of quantative drought representation methods by drought index application. In this research, the reaction to the historical droughts is analyzed after estimation of PDSI, SPI and MSWSI(Modified Surface Water Supply Index) in south korean territory. Lastly the drought representation methods were examiner combining the drought indices by drought indices. The arithmetic mean drought indices that include PDSI, SPI, in yearly basis from 1971 to 2001 and MSWSI in yearly basis from 1974 to 2001 were estimated through the whole nation. The applicability of drought indices are examined based on the observed drought data for national and regional droughts. The result shows that PDSI, SPI(3), SPI(6), and MSWSI have proven to be sensitive enough to the historical drought. The correlation analysis of each drought index was conducted whether they could show the long and short term drought equally. The analysis of how appropriately represent for the historical drought was used for determining for the combined drought index. Consequently, PDSI, SPI(3), SPI(6), and MSWSI have been appeared as suitable indices for the development of quantitative drought representation methods. For the decision of weight on combining PDSI, SPI(3), SPI(6), and MSWSI, drought map was made for eighteen alternative to decide weight. The results showed that PDSI(20%), SPI(3)(60%), SPI(6)(10%), and MSWSI(10%) have been the most well matched weights. Using selected weights of each drought indices and by reconstructing the national mean drought severity on yearly basis, the fact that the year of historical drought is in accordance with the verified one for drought representation. In short, the acquired technique using combined drought index can be used for useful and believable quantitative method of drought analysis.

• 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.

• KCID journal
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• v.13 no.1
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• pp.72-81
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• 2006

The objictive of this study is to analyze regional drought using agricultural drought indicator. Toforecast and evaluate the drought, the drought indices for agriculture were applied. In the present drought preparedness plans of Ministry of Agriculture and Forestry (MAF), it is prescribed that the preparedness levels should be classified by considering the precipitation, reservoir storage, soil moisture in paddy and upland, and the growing status of crops. There are many drought index to analyze and evaluate the drought. However, these indices do not exactly explain all drought events. Thus, we select 4 drought indices to evaluate agricultural drought:reservoir storage index, 3-month delayed SPI, mean rainfall index, and dry day index. Using these ineices, six drought stages are classified. The results show that agricultural drought could be apprppriately analyzed and evaluated by agricultural drought stage and four drought indices.

• Journal of Korea Water Resources Association
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• v.39 no.9 s.170
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• pp.787-800
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• 2006

This study is to develop the drought monitoring system of Korea using drought indices such as PDSI, SPI and MSWSI. To analyze the applicability of three different drought indices, monthly based drought indices have been calculated using various kinds of meteorological and hydrologic data. Also past drought events have been investigated to compare the simulation results, which are the severity, duration and locations using monthly drought indices. The drought map which is made by using PDSI shows the best accordance with past drought events in its severity and duration as well. Also SPI(3) shows good accordance with past drought events. As a results of this study, we concluded that three different drought indices can be used as an effective tool for quantitative drought monitoring.

• Journal of Korea Water Resources Association
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• v.44 no.8
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• pp.639-652
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• 2011

In this study, the suitability of drought indices was analyzed using the quantified drought records from official reports, newspapers and drought indices estimated using precipitation and air temperature data of 69 weather stations from 1973 to 2009. Test statistics of the suitability of meteorological drought indices were evaluated using the ROC analysis. Results demonstrated that PN shows the best relationships with drought records. SPI3 and Deciles Distribution Ratio also show good relationships with drought records and their variability according to the administrative divisions is relatively small. Results of the analysis of the spatial and temporal variability of drought and the accuracy of the drought indices can be used to evaluate the accuracy of drought indices in drought monitoring and prediction, and to select the best index in drought management.

• KCID journal
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• v.21 no.1
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• pp.78-88
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• 2014

This study is to analyze the 2012 spring drought of Korea using drought index and satellite image. The severe spring drought recorded in May of 2012 showed 36.4% of normal rainfall(99.5mm). The areas of west part of Gyeonggi-do and Chungcheong-do were particularly serious. The drought indices both the SPI(Standardized Precipitation Index) and WADI(WAter supply Drought Index) represented the drought areas from the end of May and to the severe drought at the end of June. The drought by SPI completely ended at the middle of July, but the drought by WADI continued severe drought in the agricultural reservoir watersheds of whole country even to the end of the July. On the other hand, the results by spatial NDVI(Normalized Difference Vegetation Index) and EVI(Enhanced Vegetation Index) data from Terra MODIS, both indices showed relatively low values around the areas of Sinuiju, Pyongyang, and west coast of North Korea and Gyeonggi-do and Chungcheong-do of South Korea indicating drought condition. Especially, the values of NDVI and EVI at Chungcheong-do were critically low in June compared to the normal year value.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.509-518
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• 2016

This study assessed drought of Cheongmicheon watershed from 1985 to 2015 according to duration. In order to quantify drought, we used meteorological and hydrological drought index. Standardized Precipitation Index(SPI) based on precipitation and Standardized Precipitation Evapotranspiration Index(SPEI) based on precipitation and evapotranspiration were applied as meteorological drought index. Palmer Drought Severity Index(PDSI) and Stream Drought Index(SDI) based on simulation of Soil and Water Assessment Tool(SWAT) model were applied as agricultural and hydrological drought index. As a result, in case average of extreme and averaged drought, 2014 and 2015 have the most vulnerable in all drought indices. Variation of drought showed different trend with regard to analysis of frequency. Also, the extreme and averaged drought have high correlation between drought indices excluding between PDSIs. However, each drought index showed different occurrence year and severity of drought Therefore, drought indices with various characteristics were used to analysis drought.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.7-13
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• 2005

There are two ways to mitigate the drought. One is the structural measures such as storage of irrigation water, development of emergency wells, etc. The other one is the nonstructural measures such as water saving management by the early warning system. To precast and evaluate the drought, we need to develop the drought indices for agriculture. In the present drought preparedness plans of Ministry of Agriculture and Forestry (MAF), it is prescribed that the preparedness levels should be classified by considering the precipitation, reservoir storage, soil moisture in paddy and upland, and the growing status of crops. However there are not clear quantitative criteria for consistent judgment. This shows that we have not selected and utilized the proper drought index for agriculture and we did not have the information system to calculate the drought indices periodically and warn the outbreak of the drought. The objectives of the study are to develope of Agricultural Drought Evaluation System and to evaluate this indices for current agricultural status using the system.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.3
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• pp.140-152
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• 2017

The Korea Meteorological Administration (KMA) regularly publishes various drought indices. However, most of these are meteorological drought indices that are not only difficult but often inappropriate to apply to agriculture. In this study, the meteorological drought index and the agricultural drought index were calculated for the representative points of South Korea during the same period, and the differences in geographical distribution were analyzed according to the characteristics of drought. Although the overall drought patterns estimated by multiple drought indices were similar, the differences were also confirmed due to the different simulation methods depending on the character of drought. Especially, agricultural drought index (ADI) showed higher accuracy in the agricultural sector than that of meteorological drought index (e.g., SPI, PN). In addition, the drought patterns in recent years analyzed by ADI were more severe in spring and early summer compared with normal year. In autumn and winter, drought was weaker than normal year. For the recent periods, inland areas had more droughts than coastal areas. Considering the specific drought indices for the individual sectors, it will be helpful to take measures against drought according to the individual characteristics.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.3
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• pp.25-37
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• 2024

Global warming-induced drought inflicts significant socio-economic and environmental damage. In Korea, the persistent drought in the southern region since 2022 has severely affected water supplies, agriculture, forests, and ecosystems due to uneven precipitation distribution. To effectively prepare for and mitigate such impacts, it is imperative to develop proactive measures supported by early monitoring systems. In this study, we analyzed the spatiotemporal changes of multiple evapotranspiration-based drought indices, focusing on the flash drought event in the southern region in 2022. The indices included the Evaporative Demand Drought Index (EDDI), Standardized Precipitation Evapotranspiration Index (SPEI) considering precipitation and temperature, and the Evaporative Stress Index (ESI) based on satellite images. The Standardized Precipitation Index (SPI) and SPEI indices utilized temperature and precipitation data from meteorological observation stations, while the ESI index was based on satellite image data provided by the MODIS sensor on the Terra satellite. Additionally, we utilized the Evaporative Demand Drought Index (EDDI) provided by the North Oceanic and Atmospheric Administration (NOAA) as a supplementary index to ESI, enabling us to perform more effective drought monitoring. We compared the degree and extent of drought in the southern region through four drought indices, and analyzed the causes and effects of drought from various perspectives. Findings indicate that the ESI is more sensitive in detecting the timing and scope of drought, aligning closely with observed drought trends.