Methods of trees evaluation with the site-specific effect for microclimate in urban environment: the case of study Nitra (Slovakia)

Microclimatic factors in selected vegetation structures have been monitored in a compact historical built-up layout in the Nitra municipality. We have observed relationship between microclimatic factors (air temperature, relative air humidity and surface temperature) and microclimatic environment indices (MEI). MEI were created for selected trees with varied structure on the basis of synthesis of input data (layout samples of canopy layer and urban geometry). They point out the impact of trees and environment on microclimate in an urban environment during hot days. Surface temperature is a significant factor. The model shows that the surface temperature in various structures of trees and varied urban geometry could be identified through MEI. From the microclimatic point of view, the tree cover in the narrow street with 8 MEI has the greatest cooling effect. MEI from 8 to 13 proved the cooling effect with regard to the general diameter of the area. The higher the number of MEI, the lower is the cooling effect of the trees.