Analysing the Effects of of precipitation time on vegetation cover changes using satellite images Case study: southern part of Isfahan
Monitoring the effects of precipitation on vegetation has great importance in range management. Nowadays, satellite images are used as a low-cost and fast method for vegetation study in different scales. This study aimed to monitor vegetation cover in four range types in the south of Isfahan during 1999-2009. Five Landsat images were used to calculate NDVI index. All images were taken in the last month of spring. According to results, the effects of precipitation on the vegetation cover percentage in spring varied in studied vegetation types due to their life forms and ecological characteristics. Comparing the SPI index and vegetation cover percentage of studied sites revealed that there was a significant correlation between the SPI index related to previous month and vegetation cover percentage of each month in Astragalus spp – Stipa barbata and Astragalus spp – Scariola orientali vegetation types. In other studied vegetation types including Bromus tomentellus, Astragalus spp – Daphne mucronata, their vegetation covers were more affected by the precipitation occurred in the same month.