Ecology, Environment and Conservation Paper

HAZARD ASSESSMENT OF DESERTIFICATION USING MEDALUS MODEL IN MAZAYJAN PLAIN, FARS PROVINCE, IRAN

Masoud Masoudi and R. Zakeri Nejad

Abstract

This paper presents the MEDALUS approach, a quantitative assessment of desertification, in the case study area located in the Southern part of Iran. Four main factors or indicators of desertification including: soil, climate, plant cover, and management were considered for evaluation. Then several sub-indicators affecting the quality of each main indicator were quantified according to its quality and given a weighting of between 1.0 and 2.0. ArcView software was used to analyze and prepare the layers of quality maps using the geometric mean to integrate the individual sub-indicator maps. After that the final desertification hazard map was prepared by overlaying different main indicator (quality) maps in the GIS and the final hazard classes were defined on the basis of hazard scores arrived at by the geometric mean of the main indicators. Results show that the areas under critical hazard are the most extensive class in the desertification map. In other words, most of the study area is sensitive to desertification. Results also showed that the climate and plant cover qualities and then management quality are the most important indica-tors affecting desertification process. This undesirable state has been caused by arid climate and also poor conditions of rangelands. Also the human activities play an important role in accelerating desert-ification process.