• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.525-540
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• 2000

Characteristics of precipitation in Seoul have been examined by using long-term observational data. Precipitation records from modern rain gauges were used for 1908-1996, together with the traditional Korean rain gauge (called Chukwookee) observations for 1777-1907. A linear trend analysis of seasonal total rainfall shows no significant trends over the last 200 years A wavelet transform analysis was performed to figure out the transient variations of precipitation.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.613-619
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• 2005

Recently, we are suffered enormous loss from a natural disaster and making an effort to prepare measures for dealing with disasters. This study shows the major causes of natural disasters and stricken area with the analysis of meteorological data based on the Korean Meteorological Administration and the Central Disaster Relief Center records during 1987-2003 and classifies natural disasters according to the causes and damaged conditions. In this study, the most damaged area were Gangwon, Gyeongnam and Gyeongi province as a result of a typhoon and a localized heavy rain. To establish an effective disaster measure for these area, detailed prevention plans should be established by its causes after investigating precise regional damage data analysis.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.289-302
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• 2017

During the research period, error analysis of the amount of daily precipitation was performed with data obtained from 2DVD, Parsivel, and AWS, and from the results, 79 days were selected as research days. According to the results of a synoptic meteorological analysis, these days were classified into 'LP type, CF type, HE type, and TY type'. The dates showing the maximum daily precipitation amount and precipitation intensity were 'HE type and CF type', which were found to be attributed to atmospheric instability causing strong ascending flow, and leading to strong precipitation events. Of the 79 days, most days were found to be of the LP type. On July 27, 2011 the daily precipitation amount in the Korean Peninsula reached over 80 mm (HE type). The leading edge of the Northern Pacific high pressure was located over the Korean Peninsula with unstable atmospheric conditions and inflow of air with high temperature and high humidity caused ascending flow, 120 mm/h with an average precipitation intensity of over 9.57 mm/h. Considering these characteristics, precipitation in these sample dates could be classified into the convective rain type. The results of a precipitation scale distribution analysis showed that most precipitation were between 0.4-5.0 mm, and 'Rain' size precipitation was observed in most areas. On July 9, 2011, the daily precipitation amount was recorded to be over 80 mm (CF type) at the rainy season front (Jangma front) spreading across the middle Korean Peninsular. Inflow of air with high temperature and high humidity created unstable atmospheric conditions under which strong ascending air currents formed and led to convective rain type precipitation.

• Journal of Korean Society of societal Security
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• v.1 no.4
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• pp.65-71
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• 2008

This paper presents the characteristics of internal erosion of embankment slopes due to the localized heavy rain. In this study, the existing analysis methods of filter performance in embankment materials were reviewed. Based on the theoretical concept of filter conditions to prevent particles from being carried in from the adjacent embankment materials, new analysis method was suggested. According to the new analysis method for filter performance, experimental programs were carried out to investigate the filter performance for controlling and sealing any leak which develops through the embankment materials as a result of internal erosion. Three sets of small scale laboratory tests were carried out with changing the main influence factors such as rainfall intensity, gradient of slope, embankment material condition. It was found that the new analysis method for filter performance to prevent particles from being carried in from the adjacent embankment materials was more capable approach to design the filter materials in embankment slopes. The new criterion or method for satisfactory filter performance, therefore, was recommended.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.2
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• pp.179-187
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• 1996

Sampling of precipitation occurred at Woongchon in Choongnam from the period between May 1994 and April 1995 was made, and analysis on the data was carried out on observed pH values of the precipitations. It was found that weighted mean pH values were .sim. 4.8 and that acid rain occurred at the site of the Yellow Sea's coastal area. The results agree well with the earlier observations made at other sites of a background monitoring network. The annual values observed at the background monitoring sites were too low in comparison with the mean pH values (5.3 .sim. 5.9) obtained from urban stations of the Ministry of Environment. It was observed that values of pH in rain water often changed with time during the event of precipitation, and the low values usually depended on an airflow and a cyclone that originated in the source region.

• Atmosphere
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• v.24 no.1
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• pp.77-87
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• 2014

The radar reflectivity is significantly affected by ground clutter, beam blockage, anomalous propagation (AP), birds, insects, chaff, etc. The quality of radar reflectivity is very important in quantitative precipitation estimation. Therefore, Weather Radar Center (WRC) of Korea Meteorological Administration (KMA) employed two quality control algorithms: 1) Open Radar Product Generator (ORPG) and 2) fuzzy quality control algorithm to improve quality of radar reflectivity. In this study, an occurrence of AP echoes and the performance of both quality control algorithms are investigated. Consequently, AP echoes frequently occur during the spring and fall seasons. Moreover, while the ORPG QC algorithm has the merit of removing non-precipitation echoes, such as AP echoes, it also removes weak rain echoes and snow echoes. In contrast, the fuzzy QC algorithm has the advantage of preserving snow echoes and weak rain echoes, but it eliminates the partial area of the contaminated echo, including the AP echoes.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.241-248
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• 2003

In August 2002, side wall of OO tunnel, at the Bonghwa, Kungbuk province, Korea, was collapsed by abruptly applied heavy soil and water pressure to side wall from a inclined shaft when there was a heavy rain. These days, Inclined shaft is used for the purpose of reducing construction time, using ventilation system, using the out of carrying equipment and mucking when we construct tunnel in the world. Recently constructed tunnel has the source of inclined shafts, but the more time elapse, we lose the source of the inclined shaft such as exact position, condition, and the fact that whether inclined shaft is exist or not. Therefore, this study inspected the interior's appearance, analyzed structure to evaluate the reason of collapsing side wall and this study also performed the repairing work. Finally, we show improving maintenance method to prevent that similar accident that might be happened.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.621-627
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• 2005

It is analysised the causes and extent of damage of natural disasters through the investigating of natural disaster states occurred in Gyeongsangnam-do. The data for this study were based on disaster annual report between 1987 and 2003. Especially, the data between 1993 and 2003 were used for the analysis in Gyeongsangnam-do area. A typhoon and a heavy rain were the major causes of the natural disasters in Gyeongsangnam-do. For all that the extent of damage by a heavy rain was twice as much as that of a typhoon, Gyongsangnam-do suffered heavy damage from a typhoon. So, special attentions should be paid to establish prevention plans for that in this area. Also, half of the natural disasters were occurred between July and August, the intensive prevention plans for the summer season are needed.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.147-157
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• 2022

Electrochemical characteristics and damage behavior of 6061-T6 aluminum alloy used as a battery housing material for electric vehicles were investigated in solution simulating the acid rain environment with chloride concentrations. Potentiodynamic polarization test was performed to analyze electrochemical characteristics. Damage behavior was analyzed through Tafel analysis, measurement of damage area, weight loss, and surface observation. Results described that corrosion current density was increased rapidly when chloride concentration excceded 600 PPM, and it was increased about 7.7 times in the case of 1000 PPM compared with 0 PPM. Potentiodynamic polarization experiment revealed that corrosion damage area and mass loss of specimen increased with chloride concentrations. When chloride concentration was further increased, the corrosion damage area extended to the entire surface. To determine damage tendency of pitting corrosion according to chloride concentration, the ratio of damage depth to width was calculated. It was found that the damage tendency decreased with chloride concentrations. Thus, 6061-T6 aluminum alloy damage becomes larger in the width direction than in the depth direction when a small amount of chloride is contained in an acid rain environment.

• Journal of the Korean Institute of Educational Facilities
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• v.13 no.4
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• pp.31-42
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• 2006

This study is about an analysis of the relation between the degree of cognition of student's acts within limits when coping with several types of disaster and the degree of cognition of damage by disasters in the method of multiple regression analysis. The dependent variable is the degree of cognition of student's acts within limits and the independent variable is the degree of cognition of damage by disasters such as heavy snow, typhoon, heavy rain, heat, and yellow sand. A survey of graduates of metropolitan area high-schools has found that there are no difference between girls and boys of the degree of cognition of student's acts within limits when coping with disasters. This study finds that the independent variable, which are playgrounds, animals and plants, streets and roads, altitude and incline, gives positive effect to the degree of cognition of student's acts within limits when coping with typhoon or heavy rain in order. The study also finds that the degree of cognition of student's acts within limits when coping with heavy snow is affected positively by streets and roads, playgrounds, altitude and incline in order. It also shows that there are factors that has an effect to the degree of cognition of student's acts within limits when coping with yellow sand and heat. This study proposes suggestions to facility plans based on these facts discovered.