광주·전남지방의 폭염특성과 영향에 관한 연구

Abstract

In order to cope with the heat wave which is the most worrying as a weather disaster in summer due to the recent climate change, various researches are needed not only for coping with after the occurrence of the heat wave, but also for preventing the damage in advance. Therefore, in this research, we investigated the frequency, start date, end date, duration and intensity of the heat waves occurred in 25 regions of Gwangju and Jeonnam regions during the recent 6 years(2011~2016), and the analysis of the spatio-temporal statistical characteristics connected with changma and synoptic meteorological characteristics that affect the occurrence and intensity of the heat wave. And we also carried out the health vulnerability assessment for the influence of the heat wave so that it could be used for the establishment of measures against the heat wave and the disaster management of the primary local government. For the statistical characteristics of the heat wave, the annual average days of the heat wave in Gwangju and Jeonnam regions during the recent 6 years are 12.1 days which are more than during the recent 10 years(2007~2016), and the highest is in Hwasun and Gurye(26.1~26.5 days), and the lowest is in Heuksando and Yeosu(0.8~2.1 days). The geographical characteristics of insular, coastal regions where thermal cycling of the ocean with large heat capacity and water vapor works in the daily periodicity and inland basins and mountainous regions are well shown. It occurred a little more in May when the heat wave starts than in June, and more in September than in May, or June. The earliest heat wave was on May 24 which occurred in Gurye, Suncheon, and the latest heat wave was on September 22 which occurred in Hwasun. While recently early heat wave, dry changma and late summer heat wave were mixed, the early heat wave occurred much four times in Gurye, Hwasun where it was relatively less influenced by the ocean. The longest duration days and average maximum intensity of the heat wave were 23 days(Aug. 3~Aug. 25) and 34.8℃ occurred in Naju and Hwasun, and the lowest intensity was average of 33.6℃, 1.2℃ lower in Heuksando which was affected by the ocean. In addition, in the inland basins and mountainous regions, Gurye, Hwasun, unlike insular, coastal regions, the influence of the ocean was blocked, and the heat was accumulated by főhn phenomenon where dry air flows in from the slope of the mountain range, and the unique topographic effect of the basin like an iron pot, so there were many heat waves which lasted for a long time of more than a week. Especially, if a heat wave lasts for a long time of more than 2 weeks, the soil moisture is reduced by the heating of the ground surface, the atmosphere is further dried, and the temperature rise is accelerated. Due to this feedback, the heat waves of strong intensity of average 35.0℃. or more occurred frequently. Recently changma came earlier than normal years and while the days of changma increased by 1 to 2 days more than normal, the precipitation and rainy days decreased(81%, 0.3 days), so the increase tendency of the heat wave days(6.1 → 12.1 days) became clear. The precipitation and rainy days rather than changma period contributed relatively much to the occurrence of the heat wave. For the synoptic meteorological characteristics, in the case of 2016, which recorded the longest heat wave lasting days, the atmospheric upper-middle of high pressure belt developed from east to west, so the flow of atmospheric pressure system around the Korean peninsula was stagnant, and it played the role of blocking to confine the flow of high temperature, dry air which is 3 to 5℃ higher than the average years flowing in from China. As the atmosphere stabilized, convection was suppressed, cloud development was reduced and solar radiation was added, so the longest 23 days of the heat wave period was recorded in Naju and Hwasun, which was located in the central inland of Jeonnam. For the future of the 21st century heat wave prospect according to the climate change prospect report of the Korea Meteorological Administration, the number of the heat wave days of Gwangju and Jeonnam regions are expected to increase rapidly 1.5 to about 5 times higher than the current climatic value in the middle, or the latter half of the 21st century. The frequent occurrence areas of the latter half of the 21st century will be Gwangju(Seo-gu, Gwangsan-gu, Nam-gu) and Naju, and are expected to be annual average maximum around 80 days, and the minimum prospect areas will be Wando, Jindo and Gurye and are expected to be annual average around 50 days or more. Also, the minimum temperature of the day in the latter half of the 21st century will be 13.5℃, which is 0.3℃ higher than the current mean temperature of the day in Jeonnam region, and -0.1℃ lower in Gwangju region. In Gwangju and Jeonnam regions where the population of elderly people aged 65 and older is large which is relatively vulnerable to the danger of the heat wave(Gwangju 11.8%, Jeonnam 21.3%), women are inevitably engaged in agriculture, forestry and fishery, and during the recent 4 years(2013~2016), 760 patients with heat-related illness were found and 10 of them(6 women) died. The evaluation of health vulnerability by the heat wave utilizing VESTAP of Korea Environment Institute is weaker as the composite index is closer to 1, and at the evaluation results of Gwangju(5 gu's) and Jeonnam(22 cities and counties), the composite index of Nam-gu, Gwangju(0.46~0.48) and Naju, Jeonnam(0.46~0.49) is the highest, and among them, Daechon-dong of Nam-gu(0.29) and Seongbok-dong of Naju(0.44) is expected to be relatively more vulnerable. In the above mentioned areas, it is analyzed that it is necessary to expand social and economic infrastructure and to make strategically response efforts to the climate exposure sector, the temperature rise. The data of this research reflecting the social needs and the environment of the region is expected to be useful as a fundamental material for the establishment of a research base for the heat wave and disaster management, but it is still insufficient to utilize it for the heat wave forecast. If the potential influence of the heat wave is confirmed by accumulating sufficiently the data of patients and deaths of heat-related illness by each primary local government in the future, and the assessment is carried out by continuously updating social statistics, climate data, etc. which are utilized for the vulnerability assessment, that will be, we hope, the practical materials for the establishment of the counter policy of the heat wave.