Estimation of vegetation fraction in the Central arid region of Iran using satellite images (Case study: Sheitoor basin, Bafgh)

Vegetation is an important component of global ecosystems. Determining of the Earth''s vegetation cover is important to understand land-atmosphere interactions and their effects on climate، soil erosion، drought and natural resources management. The main objective of this study is to estimate vegetation fraction (Fv) using various vegetation indices. First، vegetation fraction was collected in 52 random sample plots in July 2009. Some vegetation indices (ARVI، DVI، EVI، SAVI، SAVI2، TSAVI، SARVI، WDVI،NDVI، PVI، IPVI، GEMI، MSAVI1، MSAVI2، OSAVI، SR، MSR) and ALOS (AVNIR2) imagery (June 2009) were used to find the most suitable index for estimating of Fv. Validation of the obtained results have been done using two methods of Cross-Validation and، dividing measured samples to calibration and validation data. Result revealed that selecting the calibration and validation data randomly، leads to different results. Generally، among all studied vegetation indices، those VIs use soil line coefficient، have higher R2 (>0. 63) and lower RMSE (<3%).