Risk analysis of landslides along the Chillanes–San Pablo de Atenas Road

Abstract

This study analyzed the risk of landslides along the Chillanes-San Pablo de Atenas road in 
Bolívar Province, Ecuador. The objective was to identify the physical and territorial factors that 
contribute to slope instability, with the aim of transforming this assessment into a practical tool 
for the preventive management of road infrastructure. To this end, Geographic Information 
Systems (GIS) were integrated with the Analytic Hierarchy Process (AHP), structuring the work 
into five key stages, from the collection and cleaning of geospatial data to statistical validation 
using the ROC curve. The model prioritized three key variables: slope, lithology, and distance 
from the road network, processed at a resolution of 12.5 m and validated against an actual 
inventory of mass movement events. The results showed that slope emerged as the critical 
factor with a weight of 0.724, leaving lithology (0.193) and proximity to the road (0.083) in 
the background. The model identified 49 critical sections with high and very high susceptibility 
levels, concentrated in the Perezán sector, specifically between kilometers 13 and 14. Given that 
17.8% of the total area presents this level of threat and that the validation yielded an AUC value 
of 0.885, the model is considered to have a very favorable predictive capacity. In conclusion, 
this methodology not only offers reliable technical support for prioritizing maintenance and 
monitoring in this Andean corridor but also lays the groundwork for replication in other 
mountainous areas with similar geomorphological conditions.