The Sahel is suffering from severe aeolian disaster, which seriously affects the survival and development of local residents. This study compares the applicability of different evaluation methods to the aeolian disaster risk evaluation in the Sahel and the optimal evaluation model is proposed. Four subsystems of aeolian disaster risk are established, and the spatial distributions of hazard, sensitivity, vulnerability and restorability are obtained respectively. The spatiotemporal changes of aeolian disaster risk in the Sahel from 2000 to 2020 are analysed. The findings show that the variable fuzzy recognition (VFR) based on natural disaster risk index model is the most suitable method for aeolian disaster risk evaluation in the Sahel, with an overall accuracy of 89.72%. The middle of the Sahel located in the desert-grassland transition zone is undergoing a sensitive climate and close proximity to sand source, with high hazard, sensitivity and vulnerability, leading to very high risk of aeolian disaster. From 2000 to 2020, very low and very high levels of aeolian disaster risk in the Sahel were decreasing, low and high levels were increasing, and the change of moderate risk level remained relatively stable. Low, moderate, and high risk are more sensitive to climate change and human activities, undergoing greater change intensity. Human activities are the main factors that increase (Northern Sahel) and reduce (Southern Sahel) aeolian disaster risk. The study is helpful to identify aeolian disaster risk levels and the changes in the Sahel, providing reference for the local government to prevent and control aeolian disaster.
 

Aeolian disaster; Variable fuzzy recognition; Natural disaster risk index model; Spatiotemporal changes; Sahel