ارزيابي تغييرات پوشش گياهي دشت سراب و تحليل دو دوره خشكسالي و ترسالي

The Evaluation of Vegetation Cover Changes in Sarab Plain: the Application of NDVI and VHI Index for Dry and Wet Years

The aim of this paper is to determine land cover change due to precipitation fluctuations with an application of Landsat images in dry and wet years. Precipitation data in were arranged for Sarab plain. Using Z Standard method, the driest and wettest years were chosen. Then Landsat Images for these two years selected. (Landsat ETM+ for dry and Spot image for wet years). Using GPS and filed works f* points in the Sarab plain were selected for Geo- referencing. After image correction, VHI index was used for each two images. NDVI Index for each image was calculated. VCI and TCI Index Vegetation Condition were then used for any two years. Finally, ERDAS imaging software change detection method was applied for determining changes between any two years. Obtained results show that vegetation cover in healthy conditions has excessive fluctuations in dry farming.