Comparison of Pixel and Subpixel Methods for Mapping Rangeland Vegetation Cover (Case study: Semirom Region, Isfahan Province)
Among the various desertification processes and vegetation degradation are the main processes in rangelands and it often starts with the reduction of vegetation cover. This can result from single or combined effects of overgrazing, rainfall deficits. The effects of these are the appearance of barren soils and an increased susceptibility to wind and water erosion. Vegetation cover is one of the most important components of the earth's surface. It strongly influences evapotranspiration, infiltration, runoff and soil erosion. Vegetation cover is also the principal factor limiting stocking rates in managed grazing lands. It has been widely recognized as one of the best indicators for determining land condition. Therefore, land condition can be assessed and monitored according to vegetation cover and its variations in time and space. This component is often used as the key indicator in the remote sensing of land condition. Assessment and monitoring is an important and essential step for rangeland management. Nowadays, satellite images are used in different scales to study vegetation cover. Usually, data vegetation changes are evaluated with studying vegetation spectral characteristic. This study aimed to compare and evaluate pixel (vegetation indices, VIs) and sub-pixel (spectral mixture analysis, SMA) methods in mapping vegetation cover in Semirom region, Isfahan province, using Landsat TM data...