Development of Taxonomy Model in order to reach an appropriate method for desertification assessment and privation of desertification intensity map (Case Study: Khezr Abad Area, Yazd, Iran)

Classification and provision of desertification intensity map، as an efficient tool، has an important role in evaluation of environmental capability and prevention of desertification and reclamation of degradation lands. So far، different models and methods have been proposed in local، national، and international scales، such as Medalus method، Iranian classification of desertification (ICD) and etc. Investigation of mentioned models shows that these models have some deficiencies such as exotic and qualitative indices and expertise mistake. Therefore، Taxonomy Model has developed as base of the desertification assessment model. The model has developed in connection with four principles: a) Natural resources evaluation and Comprehensive knowledge of effective desertification indices، b) determination of terrain mapping units (TMU)، c) Classification of criterion with uniform and similar scale and finally classification and provision of desertification intensity map. This paper investigates the abilities of Modify Numerical Taxonomy model (MNT) to assess lands sensitivity to desertification. and was applied in Khezr Abad region، with 78180 ha area. Results show that MNT model has high ability to assess desertification risk and provision of desertification intensity map. Weighted average of the quantitative value of desertification intensity was estimated at 0. 74 for all the study area (intense class of desertification risk). Investigation of weighted average of the quantitative values of human and natural desertification benchmarks shows prevailing of natural benchmarks over human factors، so that weighted average of natural benchmarks have been assessed at 0. 79 (very intense class of desertification risk) and weighted average of human benchmarks have been assessed at 0. 37 (moderate class of desertification).