Rockfall risk Mapping Using Multiple Criteria Decision Making (MCDM) AHP, and Fuzzy-Gamma methods in Khorramabad-Pol-e-Zal Freeway

Khorramabad-Pol-e-Zal freeway is one of the mountainous and high-risk routes that need to study the risk of rockfall. Therefore, the present study was conducted to investigate and zone the risk of rock fall on the Khorramabad-Zal freeway in 1400. In this study, fuzzy-gamma and AHP multi-criteria decision-making methods were used to prioritize and weigh the criteria. All studied layers and sub-layers include: land use, distance from faults, average rainfall, distance from waterways, distance from roads, slope classes, slope direction, lithology, and digital elevation model (DEM) They were weighed using the fuzzy-gamma method and ranged from 0 to 1 and Fuzzy layers with gamma value (γ) of 0.95 were combined and maps of areas prone to rock fall in the study area were obtained. Then, using the AHP method, areas at risk of rock fall Khorramabad-Pol-e-Zal freeway were identified. The results of the AHP method showed that the distance from the road with a weight of 0.1633 and the rock material with a weight of 0.1621 is the most important principles for measuring the risk of rockfall. The results showed that the Hierarchical Analysis (AHP) method compared to the fuzzy-gamma method identified areas more prone to rock fall risk, which indicates the higher accuracy of this method compared to the fuzzy-gamma method.