Evaluation of human thermal comfort using UTCI index: case study Khorasan Razavi, Iran

The Universal Thermal Climate Index (UTCI) addresses these shortcomings by using an advanced thermo-physiological model. The aim of this study was to investigate and prepare zoning of thermal comfort condition using UTCI. Meteorological data including temperature, wind speed, cloudiness and relative humidity were obtained on a daily time scale from 10 synoptic stations during (2004-2013) period. For the calculation of UTCI index Ryman and Bioklima softwares were used. Then the relationship between UTCI and elevation was investigated and by using Digital Elevation Model (DEM), UTCI zoning was prepared. The results showed that there is a strong inverse relationship between UTCI and elevation. Spatial and temporal zoning maps showed the highest values of UTCI were observed in the northeastern part of province (Sarakhs station) on July. In the cold months the lowest values of UTCI has been recorded in January. Extreme heat stress was observed across the East, South and South-East of Khorasan Razavi province. While cold stress has been more dominant In the Central and northern areas of the province. Generally there is a significant correlation between the thermal comfort and elevation, so that thermal stresses are often observed in the low regions in the warm period of the year.