Open AccessTrend Analysis and Temporal and Spatial Distribution of Wet Bulb Globe Temperature as a Heat Stress Index in Iran during the Summer Season over a 30-year Period
Author(s) -
Gholamabbas Fallah Ghalhari,
Somayeh Farhang Dehghan,
Elham Akhlaghi Pirposhteh,
Mehdi Asghari
Publication year - 2021
Publication title -
journal of environmental health and sustainable development
Language(s) - English
Resource type - Journals
eISSN - 2476-7433
pISSN - 2476-6267
DOI - 10.18502/jehsd.v6i4.8153
Subject(s) - wet bulb globe temperature , environmental science , wet bulb temperature , climatology , heat index , index (typography) , heat stress , trend analysis , spatial distribution , humidity , meteorology , geography , relative humidity , atmospheric sciences , statistics , mathematics , world wide web , computer science , geology , remote sensing
Global warming is one of the most important environmental problems that have raised researchers’ attention. The present study aimed to analyze heat stress trends using the Wet Bulb Globe Temperature (WBGT) index in the country of Iran during the summer over a 30-year period.
Materials and Methods: Daily summertime statistical data regarding mean temperature and mean relative humidity, taken from 40 synoptic meteorological stations across Iran during a 30-year period were obtained from the Iranian National Meteorological Department. The De Martonne climate classification system was used to categorize various climate regions of Iran. The WBGT index was calculated using the formula given by the Australian Bureau of Meteorology. The Mann-Kendall statistical test and the Sen's slope estimator were used to analyze the trends of the WBGT index.
Results: The WBGT index had an upward trend during the three months of June, July, and August in 71.42%, 57.14%, and 66.66% of all stations and this trend was statistically significant in 53.32%, 50%, and 42.85% of those stations, respectively. Moreover, throughout the summer, 45% of the WBGT index measurements were in the medium range (18-23°C), 37.5% were in the high range (23-28°C), and 17.5% were in the very high range (> 28°C).
Conclusion: The WBGT index followed an upward trend during the summer, especially in semi-arid regions of Iran. Considering the phenomenon of global warming, it is essential to monitor, plan ahead, and take necessary precaution measures for sensitive populations who are at high risk areas of the country.