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. In this research satellite data were used to analyze the ecotone boundary in Fars steppic rangelands using IRS LISS III and Pan data of year 2006. The real vegetation map and ecotones prepared through Geo-eye images from Google earth software and calibrated using field study. Five soil line vegetation indices such as SAVI, MSAVI2, TSAVI, OSAVI and GESAVI from processed data were calculated. Each of these indices was classified by applying density slicing analysis method. Then the accuracy of produced maps was audited with error matrix method. The results show OSAVI and SAVI had the highest overall accuracy and kappa coefficient as 82.1% and 82% for overall accuracy and 76% for Kappa coefficient, respectively. According to this research, soil line vegetation indices have intermediate accuracy for separation of arid rangelands ecotones in Iran with IRS data, although, OSAVI and SAVI perform better than the others.