• Journal of Environmental Science International
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• v.22 no.4
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• pp.443-451
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• 2013

Spring rainfall events were comprehensively analyzed based on the distribution of precipitation amount and the related synoptic weather between 2008~2012. Forty-eight cases are selected among the rain events of the entire country, and each distribution of the 24-hour accumulated precipitation amount is classified into three types: evenly distributed rain(Type 1), more rain in the southern area and south coast region (Type 2), and more rain in the central region (Type 3), respectively. Type 1 constitutes the largest part(35 cases, 72.9%) with mean precipitation amount of 19.4 mm, and the 17 cases of Type 1 are observed in March. Although Type B and C constitutes small parts (11 cases, 22.9% and 2 cases, 4.2%), respectively. The precipitation amount of these types is greater than 34.5 mm and occurred usually in April. The main synoptic weather patterns affecting precipitation distribution are classified into five patterns according to the pathway of low pressures. The most influential pattern is type 4, and this usually occurs in March, April, and May (Low pressures from the north and the ones from the west and south consecutively affect South Korea, 37.5%). The pattern 3(Low pressures from the south affect South Korea, 25%) happens mostly in April, and the average precipitation is usually greater than 30 mm. This value is relatively higher than the values in any other patterns.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.4
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• pp.37-48
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• 2018

The extreme 2017 spring drought affected a large portion of central and western South Korea, and was one of the most climatologically driest spring seasons over the 1961-2016 period of record. This drought was characterized by exceptionally low precipitation, with total precipitation from January to June being 50% lower than the mean normal precipitation (1981-2010) over most of western South Korea. In this study, for the quantitative drought impact analysis, the widely-used Standardized Precipitation Index (SPI) and the statistical drought frequency are compared with observed meteorological characteristics and anomalies. According to the drought frequency analysis of monthly cumulative precipitation during January and May in 2017, Gyeonggi-do, Chungcheong-do, and Jeollanam-do areas showed more than drought frequency over 100 years. Gyeongsangnam-do area showed more than drought frequency over 200 years based on annual precipitation in 2017. The South Korean government (Ministry of Agriculture, Food and Rural Affairs (MAFRA) and Korea Rural Community Corporation (KRC)) have been operating a government-level drought monitoring system since 2016. Results from this study can be used to improve the drought monitoring applications of future drought events, as well as drought planning and preparedness in South Korea.

• Journal of Animal Science and Technology
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• v.61 no.6
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• pp.324-332
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• 2019

This study aimed to identify the causality between climatic and soil variables affecting the yield of Italian ryegrass (Lolium multiflorum Lam., IRG) in the paddy field by constructing the pathways via structure equation model. The IRG data (n = 133) was collected from the National Agricultural Cooperative Federation (1992-2013). The climatic variables were accumulated temperature, growing days and precipitation amount from the weather information system of Korea Meteorological Administration, and soil variables were effective soil depth, slope, gravel content and drainage class as soil physical properties from the soil information system of Rural Development Administration. In general, IRG cultivation by the rice-rotation system in paddy field is important and unique in East Asia because it contributes to the increase of income by cultivating IRG during agricultural off-season. As a result, the seasonal effects of accumulated temperature and growing days of autumn and next spring were evident, furthermore, autumnal temperature and spring precipitation indirectly influenced yield through spring temperature. The effect of autumnal temperature, spring temperature, spring precipitation and soil physics factors were 0.62, 0.36, 0.23, and 0.16 in order (p < 0.05). Even though the relationship between soil physical and precipitation was not significant, it does not mean there was no association. Because the soil physical variables were categorical, their effects were weakly reflected even with scale adjustment by jitter transformation. We expected that this study could contribute to increasing IRG yield by presenting the causality of climatic and soil factors and could be extended to various factors.

• Water for future
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• v.11 no.2
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• pp.62-69
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• 1978

Interstational and interseasonal analyses of the correlation and variability in the seasonal and annual precipitation for 10 basic synoptic stations in South Korea, on the basis of rainfall record of over 40 years, are carried out. It is found that the climatic regions of precipitation could be classified by means of the interstational analysis for the correlations. Corrleation coefficients in interstational relationship of precipitation are lowest in autumn which characterizeds a strong locality while the highest value shows a relatively weak locality in winter. Interseasonal relationship between summer and winter precipitation shows mostly 10 percent significant level with all positive values. The magnitude of the variation coefficients are appeared to be in the order of winter, autumn, spring and summer. It is shown that the highest which is winter ranges between 0.33 0.58, and for the lowest summer, 0.26-0.44, respectively in the areal distribution of the coefficient. The secular changes of the variation coefficient in the recent trend show increases in spring at two station; Seoul and Incheon, in summer at Busan and in autumn at two stations; Busan and Incheon while in winter show devreases at the whole stations. An annual variation seems to show generally a constant trend as whole for all the stations.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.552-555
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• 2007

In this study, the MODIS NDVI for the period of $2000{\sim}2007$ was collected and processed to obtain VCI and SVI which are the quantitative indexes of drought. The VCI and SVI based on NDVI can be used for understanding seasonal pattern of vegetation, drought identification and quantitative analysis of drought. VCI and SVI compared with monthly precipitation ratio to average, Standardized Precipitation Index(SPI), and etc., which are used to identify spring drought, to analyze drought region, similarity and difference in drought severity. In addition, frequency of Spring droughts were calculated for the period of $2000{\sim}2007$, and the usability of the MODIS images as a tool for establishing countermeasures against drought was presented by analyzing drought frequently areas.

• Journal of Environmental Science International
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• v.2 no.3
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• pp.179-191
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• 1993

This paper aims to know the characteristics of occurrence of the anomaly level and variability of the monthly precipitation in Kyeongnam, Korea. For this study, it was investigated 주e distribution of the annual and cont비y mean precipitation, the precipitation variability and its annual change, and the characteristics of occurrence of the anomaly level in Kyeongnam area the results were summarized as follows : 1) she mean of annual total precipitation averaged over Kyeongnam area is 1433.3mm. I'he spatial distribution of the annual total precipitation shows that in Kyeongnam area, the high rainfall area locates in the southwest area and south coast and the low rainfall area in an inland area. 2) Monthly mean precipitation in llyeongnam area was the highest in July(266.4mm) 각lowed by August(238.0mm), June(210.2mm) in descending order. In summer season, rainfall was concentrated and accounted for 49.9 percent of the annual total precipitation. Because convergence of the warm and humid southwest current which was influenced by Changma and typhoon took place well in this area. 3) The patterns of annual change of precipitaion variability can be divided into two types; One is a coast type and the other an inland type. The variability of precipitation generally appears low in spring and summer season and high in autumn and winter season. This is in accord with the large and small of precipitation. 4) The high frequency of anomaly level was N( Normal)-level and the next was LN( Low Informal) -level and 25(Extremely Subnormal)-level was not appeared in all stations. The occurrence frequency of N level was high in high rainfall area and distinguish성 in spring and summer season but the low rainfall area was not. hey Words : anomaly level, variability, precipitation, coast type, inland type.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.2
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• pp.79-87
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• 1999

$^{239+240}Pu$ concentrations in precipitation were determined for the period of May 1994 to August 1996 in oder to describe current $^{239+240}Pu$ deposition at the mid-western coat of Korea (Ansan, 37$^{\circ}$17'N, $126^{\circ}$50'E). $^{239+240}Pu$ concentration in daily precipitation varied from 0.05 to 131$\mu$Bq $kg^{-1}$ with a geometric mean of $1.26\mu$Bq $kg^{-1}$. The concentration was high in the period of Yellow Sand Storm in spring and low in wet summer monsoon. The specific $^{239+240}Pu$ concentration in daily precipitation appears to be controlled by the $^{239+240}Pu$ input to the atmosphere in spring and washout effects by precipitation in the wet summer monsoon. Wet depositional flux of $^{239+240}Pu$ varied from 4 to 123$\mu$Bq $m^{-2}d^{-1}$ with a geometric mean of $33.8\mu$Bq $m^{-2}d^{-1}$ and with a maximum in the period of Yellow Sand Storm and a minimum in the period of wet summer monsoon. $^{238}Pu$/$^{239+240}Pu$ activity raios(0.04~0.31) in precipitation for March-June period suggested that one of the major sources of Pu isotopes falling in Ansan area is the arid region of the Chinese continent.

• Journal of Environmental Science International
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• v.15 no.12
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• pp.1125-1139
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• 2006

The cluster analysis of diurnal precipitation patterns is performed by using daily precipitation of 59 stations in South Korea from 1973 to 1996 in four seasons of each year. Four seasons are shifted forward by 15 days compared to the general ones. Number of clusters are 15 in winter, 16 in spring and autumn, and 26 in summer, respectively. One of the classes is the totally dry day in each season, indicating that precipitation is never observed at any station. This is treated separately in this study. Distribution of the days among the clusters is rather uneven with rather low area-mean precipitation occurring most frequently. These 4 (seasons)$\times$2 (wet and dry days) classes represent more than the half (59 %) of all days of the year. On the other hand, even the smallest seasonal clusters show at least $5\sim9$ members in the 24 years (1973-1996) period of classification. The cluster analysis is directly performed for the major $5\sim8$ non-correlated coefficients of the diurnal precipitation patterns obtained by factor analysis In order to consider the spatial correlation. More specifically, hierarchical clustering based on Euclidean distance and Ward's method of agglomeration is applied. The relative variance explained by the clustering is as high as average (63%) with better capability in spring (66%) and winter (69 %), but lower than average in autumn (60%) and summer (59%). Through applying weighted relative variances, i.e. dividing the squared deviations by the cluster averages, we obtain even better values, i.e 78 % in average, compared to the same index without clustering. This means that the highest variance remains in the clusters with more precipitation. Besides all statistics necessary for the validation of the final classification, 4 cluster centers are mapped for each season to illustrate the range of typical extremities, paired according to their area mean precipitation or negative pattern correlation. Possible alternatives of the performed classification and reasons for their rejection are also discussed with inclusion of a wide spectrum of recommended applications.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.434-437
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• 2008

In this study, we developed a fuel moisture variation prediction model on each day after precipitation during a spring forest fire exhibition period. For this research, we selected plots in pine forest on Sam-Chuck si and Dong-hae si in Kangwon do according to a forest density(low, mediate, high) and classified a surface woody fuel by a diameter.(below 0.6cm, $0.6{\sim}3cm$, $3{\sim}6cm$, and above 6cm). A validity of this model was verified by applying a fuel moisture variation after precipitation in this spring. In the result, $R^2$ was $0.76{\sim}0.92$. This model will be a useful for improvement of a forest fire danger rate forcast through a prediction a fule moisture in forest.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.218-218
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• 2019

Jeju island has an area of $1,810km^2$ and is considered the largest island in South Korea. In Jeju Island the average annual precipitation is 1,957mm. About 54% of precipitation is estimated to be lost due to evapo-transpiration and direct runoff, and the remainder is recharged. Historically springs and puddles were the island's primary sources of water. However, after 1970 all sectors, including the urban and industrial sectors depended solely on groundwater as their water resource. As vast amount of water is being recharged the Island has many springs, especially near the coastlines. Historlcally, spring of Jeju Island formed village and make it possible to continue a life. Also it produces many values such as the spring related story, culture, tourism and ecosystems. Especially, the naturally rare phenomenon that about 900 springs appear over the whole area of Jeju Island makes it possible to call it as a natural heritage. As a result of this most springs have either been destroyed or been in the state of neglect. In some cases it has been observed that springs were preserved by nature, however majority of the cases saw springs losing their own nature as a result of abandonment. It was recorded that there were 911 springs in Jeju Island with most of them being distributed along the coast, which consequently increases their susceptibility to seawater intrusion. The objective of this study is therefore to analyze Eco-cultural and Engineering characteristics about springs in the island, highlighting its past utilization and reestablishing its potential as a source of spring.