ترسیم نقشه بیابان زایی دشت یزد- اردکان به روش فایو/ یونپ و ارزیابی تناسب آن

Desertification is important for our county because it refer to land degradation in arid, semi arid and arid semi-humid zones due to climatic and human agents. In this research that is based on FAOIUNEP provisional manner, the desertification resulting from main process of ;vegetation destruction, wind erosion and salinit. development were studied in northern area of Yazd-Ardakan basin salinity on area about 328600 hectars.The necessary information was collected, then observations and field measurements were carried out. According to mentioned method, the desertification maps for each process and both present. condition and inherent risk of desertification were seperatly drawn. Finally with. combining the maps there were provided two equal maps, one for current condition and the other for inherent risk of desertification. The results were as. foHows: a) comparing present condition with previous conditions: Vegetation have been destroyed at 31 % and 69% of lands severe and very severe respectively. About 40% and 50% of lands have become high saline and ancl medium respectively, but it was Slight or very severe at the rest of 10%. . Wind erosion degreeat 70% and 30% of lands have been medium and respcetively. b ) Slight inherent risk of desertification : Vegetation potential of total area is very severe for destroying. Salinization potential at 40% of northern area is severe and 60% of southern area is medium. Wind ersosion potential at 49% of area is severe and at 37% of area is medium. In conclusion, present condition and inherent risk of desertification is medium to severe and moderately severe respectively at area under study. In this research the criteria suitability were also assessed for area conditious and some of new and more suitable criterion with present conditions for each section were suggested.