Mapping of degradation of vegetative cover,wind erosion and salt affected soils in some of of the yazd-ardekan plain

Desertification is important for our country because it refer to land degradation in arid, semi-arid and arid sub - humid zones due to climatic and human agents. General and continuous study, local and exact investigation,and use of current quantitative models is necessary to better understanding of land degradation process and desert development. In this research that is based on FAO/UNEP provisional methodology, some of the main desertification processes such as: vegetation destruction, wind erosion, and salinization were studied from two aspects:1) current status and 2) inherent risk. This area covers about 327700 hectars, extends to north of Yazd - Ardakan basin. Then, six maps were drawn for three processes and for two aspects which mentioned above, separately in 1:50000 scale, when the field observations and measurements were carried out. Finally two equal maps were provided by combination of six previous maps. Results of this investigation show that at the present time degrees of vegetation destruction, salinization, and wind erosion are, , severe to very severe, ,, ,,medium to severe, ,, and,, slight to medium,, respectively. However, degrees of these processes from inherent risk aspect are, , very severe, ,, ,, medium to severe,,, and,, medium to severe,, respectively. Although the FAO/UNEP methodology is the best model, however it has still some problems, such as: Non quantitative of some criteria; Non sensitivity of some indexes to slight changses; Non measureable of some criteria; and Non equal the number of indexes in different processes.