Studying Plant Coverage Change in Bejoshan Chai Basin During a15-Year Period Using GIS and RS

In the nature an ecological equilibrium exists between organisms and their environment. Human being for many reasons have disturbed this equilibrium by unwise use of land and, thereby, paving the way for altering its plant coverage. Studying the changing processes of plant coverge during the known periods, their destructive consequences and the ways to improve it, are the main parameters in planning and management of land use. In this research vegetation maps of Bejoshan Chai Basin was prepared in 2 period (1993&2007) by using satellites photos, RS and GIS technique, NDVI index of plant coverage, and detailed field researches. By comparing the two vegetation maps and studying of their changing processes, among the two specified types and 6 classes of vegetation in 1993, it was found that one class has been completely wiped out due to reckless utilization of land, and the other types dispersion area have been drastically decreased due to land use alteration. In all vegetation types, coverage conditions of the range reduced one rank below and the range trend has remained negative due to severe disturbance. Utilization of the range lands by livestock or native animals in both periods was more than 2.5 times of the range capacity and plant coverage density has reduced drastically. It appears that, plant coverage alterations during these periods in the studied areas were faster than other areas with similar climates; and the human intervention was one of the main cause for the native plant coverage destruction in the region.