Estimation of severity and extent of desertification in Iran using Landsat satellite images and spectral mixture analyses methods between 1984 and 2015

In the present study, the severity and extent of desertification in Iran was evaluated using Landsat satellite images with spatial resolution of 30 m during 1984 and 2015. In this regard, new remote sensing techniques (spectral mixture analysis methods) were used. Spectral Mixture Analysis (SMA) is a technique for estimating the proportion of each pixel that is covered by a series of known cover types in mixed pixels. In this regard, changes in vegetation, soil, water, and salt marshes of the entire country were studied. Results showed that about 227000 km2 of Iran included dsertification with low intensity over the past 32 years. In addition, the areas most affected by the desertification and dried water bodies were about 33000 and 5000 km2, respectively. This indicates the occurrence of desertification with varying intensities in 15.6% of the country. Results showed that the contribution of southwest provinces (Ilam, Kermanshah, Lorestan and Khozestan) and southern provinces (Boushehr, Fars and Hormozgan provinces) were much more than other provinces.However, in the eastern and southeastern provinces of the country, due to the dominance of desert and semi-desert climate, the lowest desertification intensity was observed.