GIS-Based AHP Technique for Assessment of Desertification in Western Highlands of Algeria

Desertification is one of the most serious environmental problems at global, regional, and local levels. Several factors influence the level of land deterioration, including soil texture, parent material, slope, drainage, precipitation, plant cover, aridity, population density, road density, and livestock density. In this study, a GIS-based analytical hierarchical process (AHP) and remote sensing were integrated into a GIS environment (ArcGIS) for geospatial mapping of land desertification. A pairwise matrix (PCM) was used to determine the weights of influencing factors based on an extensive literature review. In addition, the assigned score to the sub-criteria was applied. Finally, a desertification map was generated using a weighted overly analysis (WOA) tool. The results obtained show that approximately 2% (5794km 2 ) of the lands in the study area are “non-affected” by desertification, 21% (16,290 km 2 ) are “potential,” 69% (52327km 2 ) are “fragile,” and the remaining class is “critical,” representing approximately 8% (5749 km 2 ). In terms of the accuracy evaluation, the “fragile” and “non-affected” classes were precisely estimated in comparison to other classes from the producer’s and user’s perspectives. The methodology and findings of this study can be used to assess desertification and land degradation in similar areas.