抄録
This study examined the spatial characteristics of the urban and suburban thermal environments in Nagano City, an inland basin city in central Japan, using multisite fixed-point meteorological observations conducted during the summer of 2015. The results revealed that daytime air temperature differences among land-use types were relatively modest, whereas WBGT exhibited pronounced spatial contrasts. Low-rise residential areas consistently recorded higher WBGT values owing to greater solar exposure and larger sky view factors, whereas shading from dense buildings in the urban core reduced the radiation load and lowered daytime WBGT. During nighttime, WBGT hotspots were concentrated in the urban core, reflecting enhanced heat storage and suppressed radiative cooling, whereas contrasts in suburban areas largely disappeared. Component analysis indicated that globe temperature was the dominant driver of WBGT variations, particularly during the daytime, and statistical analysis demonstrated a significant correlation between WBGT and the sky view factor. These findings highlight the critical role of radiative environments in shaping urban thermal stress. Thus, urban design strategies that reduce sky exposure and enhance shading can effectively mitigate heat-related health risks in cities with large diurnal temperature variations.
https://ror.org/0575dme84 
