Monitoring Change Vegetation Cover Using Satellite Image and Standard Drouth Index (SPI)
Monitoring of drought and vegetation change is one of the most important solutions for natural resource management. Nowadays, satellite images are used as a low-cost and fast method for vegetation study in different scales. Vegetation change is assessed using spectral characteristics. The aim of this study is to analyze and monitor the changes of vegetation cover in 4 rangelands and one forest type in in south of Esfahan and southeast of Chaharmahal and Bakhtiary in 1999-2009. To measure the vegetation change, 5 Landsat images were prepared in first half of Khordad. Evaluating the canopy cover changes indicated that the precipitation had various effects on different vegetation types based on their plant form and ecological condition. The vegetation in rangeland types was mainly correlated with spring SPI but in forest type, it was more correlated with annual SPI. Also the effects of drought on studied sites were different based on their dominant vegetation types. The correlation between SPI and vegetation indices changes were highest in rangeland types dominated by grasses. This highlights the importance of drought management in this kind of vegetation.