نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری آب و هواشناسی، گروه جغرافیا، دانشگاه یزد.
2 استاد آب و هواشناسی، گروه جغرافیا، دانشگاه یزد.
3 دانشیار اقلیم شناسی، دانشگاه فردوسی مشهد
4 دانشیار آب و هواشناسی، گروه جغرافیا، دانشگاه یزد.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
To assess thermal comfort, several different aspects such as meteorological, physiological, and socio-cultural should be considered. The integrated effect of these variables on thermal stress can be obtained and evaluated using thermal comfort indices. Thermal as a biometeorological index is of special importance. The purpose of this research is to analyze the seasonality and trend of heat stress in Iran in the period from 1981 to 2020. In this research, the Universal Thermal Climate Index (UTCI) index is one of the common thermal indices for evaluating outdoor thermal comfort, and the ERA5 data set was used. Also, RMSE, PBIAS, NSE, and RSR statistical measures were used to validate the data. The quarterly review of the UTCI index showed that this index has significant regional heterogeneity in Iran. The increase in UTCI from the north to the south of Iran leads to an increase in thermal stress. The spatial distribution of areas that do not have thermal stress during the hot period of the year is mainly consistent with the altitudes. During the cold seasons of the year, areas with a height of more than 3000 meters in Iran have mild to moderate cold stress. The investigation of the trend of thermal stress during the last four decades, which was analyzed with the corrected Mann-Kendall test, showed that the UTCI in Iran has a dominant increasing trend. The UTCI index shows an increasing trend in the spring and autumn seasons in 100% and in the winter and summer seasons in 99.83 and 99.75% of the country, respectively. The maximum significant increasing trend of the index at the level of 0.05 was achieved in the spring of 2018. In the same way, the highest value of the slope of the country's average trend is also seen with the value of 0.52 degrees Celsius in this season.
ERA5 is the fifth generation ECMWF reanalysis for the global climate and weather for the past 4 to 7 decades. The ERA5 provides hourly estimates for a large number of atmospheric, ocean-wave and land-surface quantities. An uncertainty estimate is sampled by an underlying 10-member ensemble at three-hourly intervals. Such uncertainty estimates are closely related to the information content of the available observing system which has evolved considerably over time. They also indicate flow-dependent sensitive areas. The evaluation of ERA5 data was investigated using RMSE, PBIAS, NSE and RSR statistical metrics, and the results showed that ERA5 data has high efficiency. The quarterly review of the UTCI index showed that this index has significant regional heterogeneity in Iran. The increase in UTCI from the north to the south of Iran leads to an increase in heat stress. Spatial distribution of the areas that do not have thermal stress during the warm period of the year, mainly corresponds to the altitudes. During the cold seasons of the year, areas with a height of more than 3000 meters in Iran have mild to moderate cold stress. The investigation of the trend of heat stress during the last four decades, which was analyzed with the modified Mann-Kendall test, showed that the UTCI in Iran has a dominant increasing trend. The UTCI index shows an increasing trend in the spring and autumn seasons in 100% and in the winter and summer seasons in 99.83 and 99.75% of the country, respectively. The maximum significant increasing trend of the index at the level of 0.05 was obtained in the spring of 98.02%. In the same way, the highest slope of trend value of the area averaged trend with a value of 0.52 degrees Celsius can be seen in this season.
کلیدواژه‌ها [English]
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