Wet bulb globe temperature(WBGT)is a comprehensive index obtained mainly from three parameters:black globe temperature(Tg),wet bulb temperature(Tw),and dry bulb temperature(Ta).While in field observation and numerical...Wet bulb globe temperature(WBGT)is a comprehensive index obtained mainly from three parameters:black globe temperature(Tg),wet bulb temperature(Tw),and dry bulb temperature(Ta).While in field observation and numerical simulation,black globe temperature and wet bulb temperature were not easy to obtain,so WBGT was difficult to measure and calculate directly.In order to solve this problem,air dry bulb temperature,wet bulb temperature,globe temperature,relative humidity,mean air velocity,solar radiation and wet bulb globe temperature were collected during the summer(July)in Guangzhou.Correlation analysis and regression analysis were used to get a simplified method to calculate WBGT.The results showed that dry bulb temperature,relative humidity,solar radiation and WBGT were interrelated to some extent.These three parameters could be used in the simplified method to predict WBGT,and the linear correlation and precision of this model were high.In addition,we used the measured data to verify the simplified method,and the results showed that the error of the calculated value and the measured value was all below 5%,which means the simplified calculating method is feasible and can be used in field observation and simulation research of urban thermal environment.展开更多
The wet bulb globe temperature(WBGT)has important implication for human health.Previous studies widely use the monthly data but rarely investigate the extreme WBGT because of data limitation.In this study,we use 6-h s...The wet bulb globe temperature(WBGT)has important implication for human health.Previous studies widely use the monthly data but rarely investigate the extreme WBGT because of data limitation.In this study,we use 6-h station data to analyze the changes in the WBGT and three categories(intensity,absolute threshold,and frequency indices)of extreme WBGT indices in summers of 1961-2017.It is found that the spatial distributions of long-term trends in summer mean WBGT are consistent with those in the mean temperature.The trend value of WBGT is smaller than the mean temperature,because of the decrease of relative humidity.For the extreme indices,the intensity and frequency of WBGT and fixed threshold indices have changed.The increase of intensity indices and warm WBGT days and nights,and decrease of cold WBGT days and nights have been observed in most China,especially over northwestern China.The number of days with daily maximum WBGT exceeding 31.4℃(WXge31)and minimum WBGT exceeding 27.9℃(WNge27)over southeastern China have increased since 1961.The spread of probability distributions of WXge31,WNge27,and warm WBGT days and nights is becoming wider,reflecting increased variability of extreme indices.In addition,urbanization effects on the WBGT are investigated.The impacts of urbanization on most of extreme WBGT indices are not detected,except for absolute thresholds indices.This may be due to the decrease of relative humidity in urban stations,which are almost two times larger than that in rural stations.However,we also note that the homogenization issue of humidity data may affect the conclusions.展开更多
Exposure to heat stress causes diminished work performance and leads to economic loss.In the last two decades,China has experienced both rapid economic development and environmental warming;however,the spatiotemporal ...Exposure to heat stress causes diminished work performance and leads to economic loss.In the last two decades,China has experienced both rapid economic development and environmental warming;however,the spatiotemporal variations of association between environmental heat and labor loss have been rarely investigated behind this double impact.Here,we evaluated the variation in China's heat-induced labor productivity loss and related economic cost from 2001 to 2019 and investigated the effect of economic development and regional warming.We found that decline in labor productivity because of heat stress increased significantly(p<0.05 for heavy-intensity work),and the corresponding economic loss also exhibited a drastic increase by 6-to 9-fold.The relative economic loss showed a slight but nonsignificant increase with an average value of 0.54%of the annual total earnings.At the sub-regional and sectoral level,adverse effects were more prominent in the southeast region,and the secondary industry sectors,such as construction and manufacturing,contributed to larger proportions of economic losses.The transformation of industrial structure made economic sectors more vulnerable to heat exposure,and increasingly preventive effects of air-conditioning use were noted on economic damage due to heat-induced productivity decline(36.0%relative economic benefits in 2019 compared to 9.7%in 2001).Our findings could provide a deep insight into heat burden on occupational health and heat adaptation strategies regionally under climate change,especially in developing areas with higher temperature and humidity environment.展开更多
基金Supported by the National Natural Science Foundation of China(50538040,50720165805,50808083)the 111 project(111-2-13)State Key Laboratory of Subtropical Building(2008ZB14)
文摘Wet bulb globe temperature(WBGT)is a comprehensive index obtained mainly from three parameters:black globe temperature(Tg),wet bulb temperature(Tw),and dry bulb temperature(Ta).While in field observation and numerical simulation,black globe temperature and wet bulb temperature were not easy to obtain,so WBGT was difficult to measure and calculate directly.In order to solve this problem,air dry bulb temperature,wet bulb temperature,globe temperature,relative humidity,mean air velocity,solar radiation and wet bulb globe temperature were collected during the summer(July)in Guangzhou.Correlation analysis and regression analysis were used to get a simplified method to calculate WBGT.The results showed that dry bulb temperature,relative humidity,solar radiation and WBGT were interrelated to some extent.These three parameters could be used in the simplified method to predict WBGT,and the linear correlation and precision of this model were high.In addition,we used the measured data to verify the simplified method,and the results showed that the error of the calculated value and the measured value was all below 5%,which means the simplified calculating method is feasible and can be used in field observation and simulation research of urban thermal environment.
基金Supported by the National Key Research and Development Program of China(2018YFC1507702)National Natural Science Foundation of China(42025503)。
文摘The wet bulb globe temperature(WBGT)has important implication for human health.Previous studies widely use the monthly data but rarely investigate the extreme WBGT because of data limitation.In this study,we use 6-h station data to analyze the changes in the WBGT and three categories(intensity,absolute threshold,and frequency indices)of extreme WBGT indices in summers of 1961-2017.It is found that the spatial distributions of long-term trends in summer mean WBGT are consistent with those in the mean temperature.The trend value of WBGT is smaller than the mean temperature,because of the decrease of relative humidity.For the extreme indices,the intensity and frequency of WBGT and fixed threshold indices have changed.The increase of intensity indices and warm WBGT days and nights,and decrease of cold WBGT days and nights have been observed in most China,especially over northwestern China.The number of days with daily maximum WBGT exceeding 31.4℃(WXge31)and minimum WBGT exceeding 27.9℃(WNge27)over southeastern China have increased since 1961.The spread of probability distributions of WXge31,WNge27,and warm WBGT days and nights is becoming wider,reflecting increased variability of extreme indices.In addition,urbanization effects on the WBGT are investigated.The impacts of urbanization on most of extreme WBGT indices are not detected,except for absolute thresholds indices.This may be due to the decrease of relative humidity in urban stations,which are almost two times larger than that in rural stations.However,we also note that the homogenization issue of humidity data may affect the conclusions.
基金This study was supported by the National Natural Science Foundation of China(71974092)the Fundamental Research Funds for the Central Universities,China(0207-14380179,0207-14380174,and 0207-14380055)the Frontiers Science Center for Critical Earth Material Cycling,Nanjing University,China。
文摘Exposure to heat stress causes diminished work performance and leads to economic loss.In the last two decades,China has experienced both rapid economic development and environmental warming;however,the spatiotemporal variations of association between environmental heat and labor loss have been rarely investigated behind this double impact.Here,we evaluated the variation in China's heat-induced labor productivity loss and related economic cost from 2001 to 2019 and investigated the effect of economic development and regional warming.We found that decline in labor productivity because of heat stress increased significantly(p<0.05 for heavy-intensity work),and the corresponding economic loss also exhibited a drastic increase by 6-to 9-fold.The relative economic loss showed a slight but nonsignificant increase with an average value of 0.54%of the annual total earnings.At the sub-regional and sectoral level,adverse effects were more prominent in the southeast region,and the secondary industry sectors,such as construction and manufacturing,contributed to larger proportions of economic losses.The transformation of industrial structure made economic sectors more vulnerable to heat exposure,and increasingly preventive effects of air-conditioning use were noted on economic damage due to heat-induced productivity decline(36.0%relative economic benefits in 2019 compared to 9.7%in 2001).Our findings could provide a deep insight into heat burden on occupational health and heat adaptation strategies regionally under climate change,especially in developing areas with higher temperature and humidity environment.
