Summer thermal comfort in Czech cities: measured effects of blue and green features in city centres.

This study consists of nine case studies addressing thermal comfort in the public areas of city centres, with particular emphasis on the measurable effects of blue and green infrastructure on thermal exposure. Daytime on-site measurements were taken in summer in the paved areas of squares, in the proximity of water fountains, and in the shade of trees in order to evaluate levels of heat stress based on the universal thermal climate index (UTCI). The differences in UTCI values between the research points confirm substantial cooling associated with high vegetation (trees induced differences up to 10.5 °C in UTCI), while the measurable cooling effect of low vegetation was negligible (not more than 2.3 °C UTCI). It was also quite low around water fountains, spray fountains, and misting systems. It follows that municipal authorities should consider the differences in cooling effect potential of individual types of blue and green infrastructure when incorporating climate adaptation measures into urban planning.