Mozhgan abbasi - fuaculty of natural resource and earth science, university of shahrekord, shahrekord, sharekord, iran.
Hamid reza reyahi bakhtiari - faculty of natural resources and earth sceinces university, shahrekord , iran

In the last three decades, remote sensing techniques have been applied in environment montioring. Detection of particulate air pollution by remote sens ing has well developed by determining the influence of plant condition on the behavior of spectral reflectance. most f the biochemical component and water content of leaves could be affected by stressful agent such as air pollution which in turn will influence the optical properties of leaf. filed spectroscopy is a reliable, rapid and nondestructive technique for detecting air pollution in urban areas. this paper aims to use feild spectral date to detect the spectral change caused by air polluton stress and to compare statistically the spectral reflectance of polluted and non-polluted leaves of ash using vegetation indices. we also visually compared the reflectance spectra of leaves. for this purpose, the spectral reflectance of 45 trees in two sites was acquired by analytical spectral devices inc ASD. A total of 45 spectrums were analyzed. the comparison of simulated vegetation indices and also dervative analysis of polluted and nonpolluted leaves showed some peaks that can be used to describe changes due to air polluton. the air pollution tolerance index APTI which differs signifi-cantly in two sites has a relationship to some spectral indeices. for future works identification of a number of some key features of leaf spectra that can provide a basis for the develpment of a robust tree health indicator for airborne or spaceborne or satellite hyperspectral sensors in urban areas was proposed.

air pollution, field spectroscopy, APTI, vegetation index