Mapping desertification potential using life cycle assessment method: a case study in Lorestan Province, Iran

چکیده مقاله

Abstract: In recent year, desertification has become one of the most important environmental hazards all over the world, especially in developing countries such as Iran. Understanding the factors impacting on desertification and identifying the regions with high desertification potential are essential to control this phenomenon (i.e., desertification). The life cycle assessment (LCA) method is essential in assessing the desertification of ecosystems, especially for susceptible ecosystems with high degradation risks. The aim of the present study was to evaluate the desertification potential of Lorestan Province, Iran, based on the LCA method. We selected aridity, fire and dust as three indicators of desertification and collected data from 2000 to 2015. We divided the study area into 6 types of ecoregions according to the climate types (arid, semi-arid and dry sub-humid) and dominant species (Quercus brantii and Astragalus adscendens), and calculated the characteristic factor (CF) of each indicator (aridity, fire and dust) by overlaying the layers of the indicator and the ecoregion map of the study area. In a given ecoregion, the sum of CF values of aridity, dust and fire indicators represents the total CF value of desertification (the higher the CF value, the greater the desertification potential). Then, we obtained the desertification potential map by combining and overlapping the ecoregions and the normalized indicators based on the LCA method. Aridity and fire exhibit significant impacts on desertification in the study area compared with dust. In the study area, semi-arid ecoregion with Quercus brantii as the dominant species is the largest ecoregion, while arid ecoregion with Quercus brantii as the dominant species is the smallest ecoregion. Arid ecoregion with Astragalus adscendens as the dominant species (total CF value of 1.99) and dry sub-humid ecoregion with Quercus brantii as the dominant species (total CF value of 0.79) show the highest and lowest desertification potentials, respectively. Furthermore, arid ecoregion with Quercus brantii as the dominant species also has a higher total CF value (1.89), showing a high desertification potential. These results suggest the necessity of proper management and appropriate utilization in these ecoregions. In general, assessing desertification potential using the LCA method on a local and regional scale can possibly provide a new methodology for identifying and protecting areas with high degradation risks.