• Clinical and Experimental Emergency Medicine
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• v.5 no.4
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• pp.272-277
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• 2018

Objective While the effect of typhoons on emergency medicine has been evaluated, data are scarce on their effects on the emergency medical service (EMS). This study evaluated the effect of typhoons on EMS patients and performance. Methods The study period was January 2010 to December 2012. Meteorological data regarding typhoons were provided by the Korean Meteorological Administration. EMS data were retrieved from the EMS database of the national emergency management agency. The database includes ambulance run sheets, which contain clinical and operational data. In this case-crossover study, the cases and controls were EMS calls on the day of typhoon warnings and calls one week prior to the typhoon warnings, respectively. Results During the study period, 11 typhoons affected Korea. A total of 14,521 cases were selected for analysis. Overall, there were no obvious differences between the case and control groups. However, there were statistically significant differences in age, place, and time requests. There were fewer patients between 0 and 15 years of age (P=0.01) and more unconscious patients (P=0.01) in the case group. The EMS operational performance, as measured by the times elapsed between call to start, call to field, and call to hospital did not differ significantly. There was also no significant difference in the time from hospital arrival between the cases (28.67, standard deviation 16.37) and controls (28.97, standard deviation 28.91) (P=0.39). Conclusion Typhoons did not significantly affect the EMS system in this study. Further study is necessary to understand the reasons for this finding.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.325-334
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• 2022

It has been more than 30 years since the term climate change began to become popular, but recently, rapid accelerated phenomena are appearing in the form of extreme weather all over the world. It is showing a distinctly different phenomenon from previous years, with heavy rain falling in the Death Valley desert in the U.S., and temperatures rising more than 40 degrees in Europe. In the Korean Peninsula, super typhoons with very strong wind speeds have become a major disaster risk for many years, and the supply of more energy due to the rise in sea temperature increases the possibility of super typhoons, requiring a proactive response. Unlike the method using numerical analysis, this study analyzed past typhoon data to study changes in typhoon characteristics for coastal disaster prevention. Existing studies have targeted all typhoons that have occurred, but in this study, a specific area was set up in the southern ocean of the Korean Peninsula and then a study was conducted. The subjects of the study were typhoons that occurred over the past 40 years from 1980 to the present, and it was confirmed that the maximum wind speed of typhoons affecting the Korean Peninsula increased slightly. The wind speed of typhoons in the specific area is about 80% of the maximum wind speed in their lifetime, and a correlation with ENSO could not be confirmed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2B
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• pp.193-205
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• 2009

Typhoons occurred in the tropical Pacific region, these might be affected the Korea moving toward north. The strong winds and the heavy rains by the typhoons caused a natural disaster in Korea. In the research, the heavy rainfall events based on typhoons were evaluated quantitative through various statistical techniques. First, probability precipitation and typhoon probability precipitation were compared using frequency analysis. Second, EST probability precipitation was calculated by Empirical Simulation Techniques (EST). Third, NL probability precipitation was estimated by coupled Nonparametric monte carlo simulation and Locally weighted polynomial regression. At the analysis results, the typhoons can be effected Gangneung and Mokpo stations more than other stations. Conversely, the typhoons can be effected Seoul and Inchen stations less than other stations. Also, EST and NL probability precipitation were estimated by the long-term simulation using observed data. Consequently, major hydrologic structures and regions where received the big typhoons impact should be review necessary. Also, EST and NL techniques can be used for climate change by the global warming. Because, these techniques used the relationship between the heavy rainfall events and the typhoons characteristics.

• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.68-75
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• 2010

Recently, the intensity and frequency of typhoons have been on the increase due to unusual weather phenomena and climate change. In particular, on September 13, 2003, typhoon MAEMI (0314) caused heavy damage in the provinces of Busan and Gyongnam, but also provided an opportunity to perform a variety of studies on storm surge. According to investigation reports on the damage resulting from typhoon MAEMI, the areas where coastal inundation occurred were located in reclaimed land under coastal development. In this study, through an image data analysis of historic and present day typhoons affecting Masan, we found that the inundation damage areas corresponded to reclaimed lands. Therefore, using the area around Busan, including the southeastern coast of Korea where typhoons lead to an increased storm surge risk, we performed a storm surge/inundation simulation, and examined the inundation effect on reclaimed land due to the intensified typhoons predicted for the future by climate change scenarios.

• Journal of the Korean Institute of Navigation
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• v.18 no.3
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• pp.19-30
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• 1994

By use of the recent tropical cyclones' data in the Northwest Pacific Ocean, the occurrence frequency and region of typhoon as well as the features of the monthly mean track were analyzed. As the result of this study, (1) mean occurrence frequency of typhoon per year is 27.5, and 68% of total typhoons were formed in July to October and shown the highest frequency in August. (2) The ave-rage duration of typhoons is 8.5 days, and super typhoon which maximum sustained surface wind speeds is more than 130 knots occurs most frequently in October and November. (3) The highest frequency ap-pears around the Caroline, Mariana and Marshall Islands, and in wintertime, typhoon occurs in lower lati-tude comparing with those in summertime. (4) The typhoon track depends upon the distribution of pres-sure system and steering current in neighbouring areas. The mean track of typhoon can be classified into three types such as westward-moving type, northward-moving type and abnormally moving type. The west-ward-moving typhoons make landfall on the southern China by way of the South China Sea in June and July, on mid-part of China in August and September, and on Indo-china Peninsula in October and Novem-ber. The northward-moving typhoons approximately move on north~northwestward track to $20~30^{\circ}N$ from the occurrence region, then recurve to the East Sea through Korean Peninsula and Kyushu Island in June and July, to the Noth Pacific Ocean along the Japanese Islands in August and September and to the North Pacific Ocean through the seas far south off the Japan in October and November.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.140-146
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• 2015

This paper analyzed recurvature of typhoons by using 20 years meteorological data from 1992 to 2011. The results of this study are as follows. Yearly numbers of typhoon recurvature showed decreasing tendency gradually with decrease of numbers of typhoon occurrence. Typhoons recurvature were especially many between August and October and number of typhoon recurvature between July and October was occupied counts for 71 % of the whole typhoon recurvature. Life of typhoon recurvature in the North Pacific was most frequent at 5 days and 7 days. Mean life of typhoon recurvature was 6.8 days and this numerical value was longer than mean life of the whole typhoon including recuevatute and non-recurvature. Most of typhoons recurvature changed their direction north-eastwards in 20-34 degrees north latitude and 120-139 degrees east longitude. Mean latitude recurvature and longitude recurvature were 25 degrees north latitude and 135 degrees east longitude, respectively.

• Wind and Structures
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• v.31 no.3
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• pp.269-285
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• 2020

The statistical characteristics of typhoon wind speed records tend to have a considerable time-varying trend; thus, the stationary wind model may not be appropriate to estimate the wind characteristics of typhoon events. Several nonstationary wind speed models have been proposed by pioneers to characterize wind characteristics more accurately, but comparative studies on the applicability of the different wind models are still lacking. In this study, three landfall typhoons, Ampil, Jongdari, and Rumbia, recorded by ultrasonic anemometers atop the Shanghai World Financial Center (SWFC), are used for the comparative analysis of stationary and nonstationary wind characteristics. The time-varying mean is extracted with the discrete wavelet transform (DWT) method, and the time-varying standard deviation is calculated by the autoregressive moving average generalized autoregressive conditional heteroscedasticity (ARMA-GARCH) model. After extracting the time-varying trend, the longitudinal wind characteristics, e.g., the probability distribution, power spectral density (PSD), turbulence integral scale, turbulence intensity, gust factor, and peak factor, are comparatively analyzed based on the stationary wind speed model, time-varying mean wind speed model and time-varying standard deviation wind speed model. The comparative analysis of the different wind models emphasizes the significance of the nonstationary considerations in typhoon events. The time-varying standard deviation model can better identify the similarities among the different typhoons and appropriately describe the nonstationary wind characteristics of the typhoons.

• Journal of Environmental Science International
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• v.30 no.9
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• pp.753-762
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• 2021

This study analyzed the characteristics of strong winds accompanying typhoons for a period of 116 years, from 1904 to 2019, when modern weather observations began in Korea. Analysis shows that the average wind speed and high wind rate caused by typhoons were higher over the sea and in the coastal areas than in the inland areas. The average wind speed was higher over the West Sea than over the South Sea, but the rate of strong wind was greater over the South Sea than over the West Sea. The average wind speed decreased by 1980 and recently increased, while the rate of strong winds decreased by 1985 and has subsequently increased. By season, the strong winds in autumn (september and october) were stronger than those in summer (june, july, and august). Strong winds were also more frequent in autumn than in summer. The analysis of the changes in strong winds caused by typhoons since the 1960s shows that the speed of strong winds in august, september, and october has increased more recently than in the past four cycles. In particular, the increase in wind speed was evident in fall (september and october). Analysis of the results suggests that the stronger wind is due to the effects of autumn typhoons, and the increased possibility of strong winds.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.119-127
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• 2022

In recent years, the intensity of typhoons has increased due to climate change. It is presumed that the tailings and waste rock in the mining area harm the environment owing to flood damage. The Gangneung area has been affected by the largest typhoons in Korea, including No. 3,693 (1936), Rusa (2002), Maemi (2003), and Megi (2004). This study was based on a case in which high concentrations of arsenic were detected in the surroundings along a stream after floods caused by typhoons. Although the environmental damage-related law clarifies the responsibility of polluters, careful implementation is required in potential natural disaster areas. The pollutants from abandoned mines can be widely exposed due to typhoons as artificial causes may be mixed. To minimize the impact of natural disasters in these areas, it is necessary to improve and link relevant laws. This study is expected to help cope with mixed pollutants in downstream areas.

• Wind and Structures
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• v.20 no.2
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• pp.293-314
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• 2015

In this paper, wireless monitoring of typhoon-induced variation of dynamic characteristics of a cable-stayed bridge is presented. Firstly, cable-stayed bridge with the wireless monitoring system is described. Wireless vibration sensor nodes are utilized to measure accelerations from bridge deck and stay cables. Also, modal analysis methods are selected to extract dynamic characteristics. Secondly, dynamic responses of the cable-stayed bridge under the attack of two typhoons are analyzed by estimating relationships between wind velocity and dynamic characteristics. Wind-induced variations of deck and cable vibration responses are examined based on the field measurements under the two consecutive typhoons, Bolaven and Tembin. Finally, time-varying analyses are performed to investigate non-stationary random properties of the dynamic responses under the typhoons.