Effects of Changing Land Use and Land Cover on the Heat Island in Urban Area of Yazd Using Remote Sensing Data

Micro clima of the present study was performed in a region of 58,730 hectares within the cities of Yazd, Ashkzr, Zarch, Shahedyh and Hamydya by the use of Remote sensing techniques. To analyze the relationship between the land use/cover changes and heat island city of multi temporal Land sat images 4 and 7 of TM and ETM sensors related to the dates 11 September 1990 and 10 July 2002 were used. The results, through the classification of images and statistical information extracted from each class shows that the city of Yazd in recent years has had relatively fast growth, resulting in significant changes in land use that has been created. Physical expansion of Yazd city from the view point of construction building area, has caused the decrease of 1.9 percent during the vegetation period of 13 years (1990-2002). Simultaneously with the increase of construction building areas and reduction of vegetation cover, the extent of heat island located on the downtown has increased. This study also showed that thermal characteristics of land surface and its patterns, can be found through the type and quality of land uses. Results of the relationship between NDVI and land surface temperature using correlation and regression analysis, expressing the effect of vegetation cover on reducing temperature due to the surface evaporation and transpiration.