Inventory and preliminary evaluation of the factors that cause landslides and affect the road infrastructure of the Barahona Province of the Dominican Republic

Landslide inventory maps constitute the primary level of information in risk prevention studies and stability analysis. The Dominican Republic, particularly the Barahona province, is exposed to various geological hazards such as slope movements due to its topographic, geological and climatic characteristics, as well as the effect of human activities. These natural phenomena directly and indirectly affect the population and their economic activities, which are essential to their development. The objective of this research is to determine the types of mass movements that directly impact the main roads of Barahona (the Enriquillo Highway and the Barahona-Paraíso Highway), the primary conditioning and triggering factors, and the resulting damage to road infrastructure. Through photointerpretation and fieldwork, a total of 22 slope movements were identified. Of these, 13.64% correspond to landslides, 68.18% to flows, 13.64% to falls, and 4.54% to topples. Most of these movements occur in geological materials of sedimentary origin, such as shales, limestones, marls, sandstones, conglomerates, and alluvial and colluvial deposits. Of the movements identified, 59.09% were classified as suspended, 22.73% as active, and 18.18% as inactive. The factors conditioning the occurrence of landslides are associated with the sedimentary geology that predominantly covers Barahona province, the rugged topography, and changes in land use. Meteorological events such as tropical storms and hurricanes bring intense and prolonged torrential rains. These precipitations, combined with active tectonics, are the main triggering factors. Finally, the damage to road infrastructure results in accumulations of displaced material on the roadway, total or partial collapse of retaining, protective, and drainage structures, differential movements causing irregularities and sinking of the asphalt layer, transverse and longitudinal cracking of the roadway, gullies, and erosion in cut and fill slopes.