Determining the Most Suitable Vegetation Index for Seperating Ecotone Boundaries in Arid Rangelands Using Satellite Data

Ecotones are zones of gradual changes from an ecological system to another.Ecotones monitoring could be important to find out the reason for changes and limits. Inthis research satellite data were used to analyze the ecotone boundary in Fars steppicrangelands using IRS LISS III and Pan data of year 2006. The real vegetation map andecotones prepared through Geo-eye images from Google earth software and calibratedusing field study. Five soil line vegetation indices such as SAVI, MSAVI2, TSAVI,OSAVI and GESAVI from processed data were calculated. Each of these indices wasclassified by applying density slicing analysis method. Then the accuracy of producedmaps was audited with error matrix method. The results show OSAVI and SAVI had thehighest overall accuracy and kappa coefficient as 82.1% and 82% for overall accuracy and76% for Kappa coefficient, respectively. According to this research, soil line vegetationindices have intermediate accuracy for separation of arid rangelands ecotones in Iran withIRS data, although, OSAVI and SAVI perform better than the others.