Monitoring the Vegetation Cover Changes by Using Remote Sensing Techniques in Ilam Dam Basin

Monitor of change is generally performed for evaluating natural processesincluding long term effects of climate change which is caused by astronomicreasons and also short term processes which includes the succession of vegetationcover and geomorphologic processes. Also change monitoring is used forevaluating the effects resulting from human activities including deforestation,agriculture and urbanization. As the environment changes reflect the situation oflands management, monitoring methods can help to evaluate these operations. Inthis study, measuring images (MSS) of year 1976 and land sat (ETM+) year 2002have been analyzed by four techniques of change monitoring in Ilam dam basinwith an area of 476.751 km2. Techniques for monitoring changes used in thisstudy include the image difference, image rating, analysis difference of the maincomponent and analysis difference of standardized main component. Since thechange monitoring techniques used in this study require the threshold, and on thisbasis it is determined that the change threshold on the under study area has beenplaced with +deviation from mean, After specifying the change threshold, theareas with decreasing, increasing and without changes have been determined. Forevaluating the accuracy of change monitoring techniques, after surveying theground realities, which obtained though field visits and Google Earth Satelliteimages, the total accuracy and Kappa coefficient were used. Based on the obtainedresults, it was determined that the difference method of red band with totalaccuracy of 89 and Kappa coefficient of 0.82 has the greatest accuracy among theused change monitoring techniques in his study and rating method of the nearinfra red band with total accuracy of 64.5 and kappa coefficient of 0.34 has hadthe least accuracy in monitoring changes of vegetation cover in the area understudy.