GIS-Based Multi-Criteria Decision Analysis Approach (GIS-MCDA) for investigating mass movements’ hazard susceptibility along the first section of the Algerian North-South Highway

Abstract

The North-South highway is a central axis of the Algerian road network. This major project is expected to enhance the socio-economic development of Algeria. However, its first section is implemented within a complex region with very contrasted landscapes marked by mass movements. In the present work, we conducted a mass movement susceptibility assessment on the first section of the road infrastructure using a Multi-Criteria Decision Analysis approach. Various data from different sources were processed in a GIS environment, and nine landslide and rockfall conditioning factors were considered: Lithology, Slope, Daily Temperature Amplitude, Rainfall, Lineament Density, NDVI, Relative Relief, Drainage Density, and Distance to Streams. Each of the conditioning factors was selected, reclassified, and ranked according to its influence on each mass movement type. Two popular GIS-MCDA methods, namely AHP and WLC, were used to weight the influence and combine the selected factors and construct the landslide and rockfall assessment models. Then, landslide and rockfall susceptibility indices were calculated and used to produce mass movement susceptibility maps of the study area. Finally, a spatial analysis was performed to assess the highway section’s susceptibility to the two mass movements. The results show that 22.49% and 12.44% of the road section are highly susceptible to landslide and rockfall hazards, respectively. Finally, the combination of the resulting map with the road chainage enabled the delineation of segments highly susceptible to landslide and rockfall hazards by kilometric points.