Multi-Criteria Evaluation Model for Desertification Hazard Zonation Mapping using GIS

Abstract

Desertification is one of the major issues threatening human communities. Many methods have been developed for assessment
and mapping of desertification hazard. In this research multi-criteria evaluation method were used to investigate desertification
process in Trouti watershed. As the first step, major desertification factors (seven information layers) including: soil texture, aspect, rainfall, sensitively of geological formation to erosion, hydrologic soil group, slope and land use were determined based on field study. The next step, information layer were digitized in GIS environment and Digitized maps were converted to fuzzy standard maps using fuzzy membership functions in IDRISI software. Then weight of each factor was determined with the contribution of Analytical Hierarchy Process. Finally, the susceptible areas to desertification in the study area were identified using Multi-criteria evaluation method. The results showed that 36.55, 15.21, 40.17 and 8.07 % of the study area were classified as severe, high,
moderate and slow affected by desertification respectively. Land use and sensitively of Geological formations to erosion were the
most important factors affecting desertification process in Trouti watershed. The goal of this research is to enable areas affected by desertification to be associated with the generation of knowledge and techniques related to GIS that can solve their specifics problems in field of desertification control. Thus, to contribute a better natural resources management and development.