• Journal of Environmental Science International
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• v.28 no.10
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• pp.863-872
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• 2019

Using the Standard Precipitation Index (SPI), this study analyzed the drought characteristics of ten weather stations in Gyeongbuk, South Korea, that precipitation data over a period of 30 years. For the number of months that had a SPI of -1.0 or less, the drought occurrence index was calculated and a maximum shortage months, resilience and vulnerability in each weather station were analyzed. According to the analysis, in terms of vulnerability, the weather stations with acute short-term drought were Andong, Bonghwa, Moongyeong, and Gumi. The weather stations with acute medium-term drought were Daegu and Uljin. Finally the weather stations with acute long-term drought were Pohang, Youngdeok, and Youngju. In terms of severe drought frequency, the stations with relatively high frequency of mid-term droughts were Andong, Bonghwa, Daegu, Uiseong, Uljin, and Youngju. Gumi station had high frequency of short-term droughts. Pohang station had severe short-term ad long-term droughts. Youngdeok had severe droughts during all the terms. Based on the analysis results, it is inferred that the size of the drought should be evaluated depending on how serious vulnerability, resilience, and drought index are. Through proper evaluation of drought, it is possible to take systematic measures for the duration of the drought.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.6-12
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• 2010

일반적으로 가뭄은 기상학적 가뭄, 농업적 가뭄, 수문학적 가뭄의 유형 등으로 분류한다. 본 연구에서는 우리나라에 적합한 수문학적 가뭄 지수인 물가용지수(Water Availability Index)를 개발하였다. 또한 다각적인 가뭄평가를 위해 기상학적 가뭄의 평가할 수 있는 표준강수지수(Standard Precipitation Index)와 농업적 가뭄을 평가할 수 있는 토양수분지수(Soil Moisture Index) 그리고 개발한 물가용지수(Water Availability Index)를 지수의 가뭄에 대한 등급을 통일시키기 위해 새롭게 산정하였다. 또한 기상청에서 제시하고 있는 월간기상정보 자료를 이용하여 가뭄전망을 할 수 있는 기법을 개발하였다.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.5
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• pp.127-136
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• 2017

The object of this study was to assess availability of meteorological drought index for agricultural dorught estimation in ungauged area of agricultural drought parameters which are reservoir water level and soil moisture. The IADI (Integrated Agricultural Drought Index) and the SPI (Standard Precipitation Index), which are the criteria for determining agricultural drought and meteorological drought, were calculated and compared. For this purpose, the droughts that occurred in the Baeksan reservoir in Gimje and the Edong reservoir in Suwon were evaluated by using the IADI and SPI drought indecies. In addition, we compared and analyzed the depth of drought based on the two drought indices. Evaluations derived form the IADI and SPI showed that the standard precipitation index tended to indicate the occurrence of drought earlier than the integrated agricultural drought index. However, the integrated agricultural drought index was better than the standard precipitation index at evaluating the severity of drought during the period of irrigation. The relationship between these two drought indices seems to be useful for decision making in the case of drought, and it is considered that more studies are needed to examine the applicability of these drought indexes.

• Atmosphere
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• v.23 no.1
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• pp.113-121
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• 2013

The objective of this study is to develop and evaluate the system to produce the real-time ensemble drought prediction data. Ensemble drought prediction consists of 3 processes (meteorological outlook using the multi-initial conditions, hydrological analysis and drought index calculation) therefore, more processing time and data is required than that of single member. For ensemble drought prediction, data process time is optimized and hardware of existing system is upgraded. Ensemble drought data is estimated for year 2012 and to evaluate the accuracy of drought prediction data by using ROC (Relative Operating Characteristics) analysis. We obtained 5 ensembles as optimal number and predicted drought condition for every tenth day i.e. 5th, 15th and 25th of each month. The drought indices used are SPI (Standard Precipitation Index), SRI (Standard Runoff Index), SSI (Standard Soil moisture Index). Drought conditions were determined based on results obtained for each ensemble member. Overall the results showed higher accuracy using ensemble members as compared to single. The ROC score of SRI and SSI showed significant improvement in drought period however SPI was higher in the demise period. The proposed ensemble drought prediction system can be contributed to drought forecasting techniques in Korea.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.2
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• pp.37-43
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• 2006

A hydrological drought index, MSWSI (Modified Surface Water Supply Index) was suggested based on SWSI (Surface Water Supply Index). With the available data of spatially distributed observation station of precipitation, dam storage, stream water level and natural groundwater level, South Korea was divided into 32 regions. This was conducted to represent the calculated index as a spatially distributed information. Monthly MSWSI was evaluated for the period of 1974 and 2001. It is necessary to compare this result with PDSI (Palmer Drought Severity Index) and SPI (Standard Precipitation Index), and check the applicability of the suggested index in our hydrological drought situation.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.1-18
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• 2022

Currently, the Korea Meteorological Administration evaluates the meteorological drought by region using SPI6(standardized precipitation index 6), which is a 6-month cumulative precipitation standard. However, SPI is an index calculated only in consideration of precipitation at 69 weather stations, and the drought phenomenon that appears for complex reasons cannot be accurately determined. Therefore, the purpose of this study is to calculate and compare SPI considering only precipitation and SDCI (Scaled Drought Condition Index) considering precipitation, vegetation index, and temperature in Gyeonggi. In addition, the advantages and disadvantages of the station data-based drought index and the satellite image-based drought index were identified by using results calculated through the comparison of SPI and SDCI. MODIS(MODerate resolution Imaging Spectroradiometer) satellite image data, ASOS(Automated Synoptic Observing System) data, and kriging were used to calculate SDCI. For the duration of precipitation, SDCI1, SDCI3, and SDCI6 were calculated by applying 1-month, 3-month, and 6-month respectively to the 8 points in 2014. As a result of calculating the SDCI, unlike the SPI, drought patterns began to appear about 2-month ago, and drought by city and county in Gyeonggi was well revealed. Through this, it was found that the combination of satellite image data and station data increased efficiency in the pattern of drought index change, and increased the possibility of drought prediction in wet areas along with existing dry areas.

• Journal of Korea Water Resources Association
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• v.46 no.6
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• pp.613-627
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• 2013

In this study, to understand the May aridity condition of each region for the year of the worst drought on record in each duration (1-, 3-, 6-, 12-, 24 months), monthly climate data recorded from 1973 to 2006 at 53 climatological stations in South Korea were used to estimate the FAO Penman-Monteith reference potential evapotranspiration (RET). Monthly precipitation and RET were used to estimate P/RET as aridity index and variation index (VI) of P/RET, and these indexes are compared with SPI (Standard Precipitation Index). Fifty three climatological stations were grouped into 20 regions, so that May aridity conditions of 20 regions were studied. Furthermore, regional trend of May aridity index was studied by applying Mann-Kendall trend analysis, Spearman rank test, and Sen's slope estimator. The study results show that variation index (VI) of P/RET and SPI have close correlation. Throughout the country, as the duration is shorter, May aridity was more severe. In case of 3-month and 6-month duration, most of region show significant or non-significant decreasing trend of aridity index. However, no region show significant decreasing trend of aridity index in case of 12-month and 24-month duration.

• Journal of Environmental Science International
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• v.29 no.5
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• pp.541-549
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• 2020

In this study, standard precipitation index- based analysis associated with run theory was performed using 53 years' (1967-2019) precipitation data to investigate the meteorological drought in Chuncheon. The duration of the meteorological drought in Chuncheon was 8.06 months, magnitude of the drought was -8.21, and average drought depth was -1.08. The drought in May 2014 lasted 21 months until January 2016; the drought scale and average depth was -34.06 and -1.62, respectively. This was the most severe drought in Chuncheon. As a result of drought frequency analysis, the drought scale of May to December in 2014 was estimated to be -16.16, and the return period was estimated to be 300 years. These results are expected to further increase the magnitude and frequency of weather droughts caused by climate change. Therefore, it is critical to prepare appropriate structural measures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.87-98
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• 2011

Recently, occurrence frequency of extreme events like flood and drought is increasing due to climate change by global warming. Especially, a drought is more severer than other hydrologic disasters because it causes continuous damage through long period. But, ironically, it is difficult to recognize the importance and seriousness of droughts because droughts occur for a long stretch of time unlike flood. So as to analyze occurrence of droughts and prepare a countermeasure, this study analyzed a meteorologic drought among many kinds of drought that it is closely related with precipitation. Palmer Drought Severity Index, Standard Precipitation and Effective Drought Index are computed using precipitation and temperature material observed by Korean Meteorological Administration. With the result of comparative analysis of computed drought indices, Effective Drought Index is selected to execute frequency analysis because it is accordant to past droughts and has advantage to compute daily indices. A Frequency analysis of Effective Drought Index was executed using boundary kernel density function. In the result of analysis, occurrence periods of spring showed about between 10 year and 20 year, it implies that droughts of spring are more frequent than other seasons. And severity and occurrence period of droughts varied in different regions as occurrence periods of the Youngnam region and the southern coast of Korea are relatively shorter than other regions.

• Ocean and Polar Research
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• v.43 no.1
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• pp.15-30
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• 2021

In this study, using 16 ORA-IP (Ocean Reanalysis Intercomparison Project) data, we investigated spatial and temporal changes of net surface heat flux in the East Asian seas and presented a new ensemble net surface heat flux index. The ensemble net surface heat flux index is produced considering the data distribution and the standard deviation of each ORA-IP. From the correlation analysis with air temperature averaged over the Korean Peninsula, ensemble net heat flux around the Korea Strait shows the highest correlation (0.731) with a 3 month time lag. For the correlation study regarding precipitation over the Korean Peninsula, it also shows significant correlation especially in winter and spring seasons. Similar results are also found in comparison with climate indices (AO, PDO, and NINO3.4), but ensemble net surface heat flux data in winter season reveals the strongest correlation patterns especially with winter temperature and spring precipitation.