Yusuke NAKAMURA, University of Tsukuba, Japan
Yuki ASANO, University of Tsukuba, Japan
Hiroyuki KUSAKA, University of Tsukuba, Japan
Heat stroke is a social issue in urban areas, because of global warming and urban heat island. A mitigation method to avoid excessive heat stress in uncomfortable thermal environments is wearing parasols and hats (Watanabe and Ishi, 2016). As both of parasols and hats are portable and inexpensive devices, wearing them can provide heat stress mitigation during walking in urban areas. However, there are few previous studies on the effect of heat stress mitigation with parasols and hats, and quantitative comparisons with other mitigation methods have not been conducted.
This study intercompared the mitigation methods by parasols, hats, street trees and dry-mist on a real urban street in Japan. For this intercomparison, the universal thermal climate index (UTCI) was observed under various heat mitigation measures. The results of this observation showed that street trees, parasols, hats, and dry-mist were more effective in mitigating heat stress, in that order. The effect with parasols on the reduction of UTCI was 5.3°C. This means that the stress category of UTCI is reduced from "Very strong heat stress" to "Strong heat stress". Also, the mitigation effect with parasols was comparable to approximately 70% of the effect with street trees. On the other hand, the effect of wearing hats on the reduction was 2.3°C.
Keywords: heat stress mitigation|urban street|parasol|WBGT|UTCI