Spatial Correlation of Assessment Between NDVI and Surface Thermal Energy in Tehran Metropolitan (1382-1395) By Using Remote Sensing

Land Surface Thermal (LST) is a key variable to control the relations between different types of radial, latent, and sensible thermal fluxes in urban areas. For analyzing and understanding dynamics of LST, it is necessary to recognize its relations with changes created by men. Recognizing such relations is a requirement for modeling and predicting environmental changes and also for urban policies. On the other hand, increases occur in vegetation cover is an effective strategy to reduce the effects of urban microclimate. The present study analyzes the trends of surface thermal changes and its spatial correlations with vegetation cover in Tehran metropolitan during 2003 to 2016. Free clouds satellite images of Tehran by Landsat8 (August 2016) and Aster (August 2003) were analyzed using Envi software. Different algorithms of remote sensing were applied to convert LST and Normalized Difference Vegetation Index (NDVI) indicators into spatial patterns. Spatial outcomes of the present study indicate that during a decade the minimum amount of surface thermal and the average amount of LST have decreased 3.67°c and 0.47°c respectively. In contrast, the average amount of NDVI was increased from 0.06 to 0.10. Also, the estimation of spatial correlation between LST and NDVI indicators showed an amount 0.02 reduction in 22 urban regions of Tehran metropolitan during the last decade. Such a reduction indicates that increasing functions of human activities have affected the rates of thermal and energy of urban surfaces. Therefore, to reduce energy consumption in the city, it is evident that different patterns of physical development should be applied for the city.