Analysis of the influence of informal settlements and artisanal mining on the stability of rock slopes

The expansion of informal settlements and unplanned artisanal mining pose a threat to the stability of rock slopes and land-use planning in mining regions. This issue is linked to the natural risks and hazards that commonly occur in unregulated mining areas. Cerro El Tablazo, located in the Santa Elena canton on the Ecuadorian coast, meets both of these conditions. In this area, artisanal mining without technical oversight and unplanned residential growth have progressively deteriorated the geometry of the rock slopes, drainage patterns, and geomechanical behavior, increasing susceptibility to mass movements. This study aims to quantify which of these factors contributes most to instability. The Mora–Vahrson method for slopes was adapted using slope, lithology, and geomorphology as conditioning factors; however, traditional triggering factors are replaced by proximity to artisanal mining fronts and informal settlements. An independent susceptibility index was generated for each in GIS. The results revealed differences between the two activities. Artisanal mining, concentrated at the top of the hill, has the greatest impact on stability due to uncontrolled excavations and the use of explosives that progressively degrade the quality of the rock slopes, while informal settlements located in ravine areas and at the base of slopes exert a lesser impact through localized overloading and modifications to drainage. The methodology applied allows for independent characterization and quantification, serving as a useful tool for assessing geological–geomechanical risk in areas where settlements and mining converge.