The survey of desertification potential in Damghan plain by using meteorological data and land use variations

In the past four decades, land use changes in Iran, have become more frequent as a human desertification factor, which has led to an intensification of land degradation in all types of land uses. In this research, due to the wide range of these changes, we used remote sensing technology to assess land use and vegetation changes in Damghan plain. The area of the study region was classified into three classes including unutilized land, lands with vegetation cover (agriculture and pasture) and urban areas using supervised classification strategy and the changes of the land uses were compared over four periods. The results indicated an increase of 184% and 1.07% respectively in urban land use and unutilized land use and a 15.7% reduction in lands with vegetation (agriculture and pasture). Using the Normalized Difference Vegetation Index(NDVI), the results of classification of vegetation in the region were such that class 1 (index less than zero), from 93.3 to 99.5 percent increase, class II( Between 0 and 0.2), from 5.6 to 0.38 percent, and the third class (index ranging from 0.2 to 0.5), from 1.1 to 0.01 percent, and class four (index ranging from 0.5 to 1) has changed from 0.03 to 0%, which indicates the validity of the findings from the review of the changes in land use, both of which indicate an increase in dry land and a decrease in vegetation. Also by using the Iranian model's climatic indices, the potential of desertification, the results of the 17-year calculations during the period of 1997 to 2013 indicated that desertification had decreasing trend in three classes: weak, severe and very severe, and increasing trend in the middle class. Finally, by combining the findings from the Iranian model and the results of remote sensing method, a weak trend in desertification based on climate criteria in the region was confirmed.