Geomorphological susceptibility to mass movements in the center - north of the Central District, Honduras

Abstract

Five geomorphological variables (slopes, lithology, river basins, escarpments and faults) were selected for their conditioning potential for mass movements in a sector of the center-north of the Central District, Honduras, with a landslide density 4 times higher than the municipal average, to generate a susceptibility analysis based on the application of GIS tools, stereoscopy of aerial photographs, lithology and fault surveys, data from remote sensors and field trips. An Analytical Hierarchy Process (AHP) was carried out to determine weights for each variable finding the following prioritization: (1) slopes, with an AHP weight of 42.9%; (2) lithology, with an AHP weight of 27.0%; (3) river basins, with an AHP weight of 13.5%; (4) scarps with an AHP weight of 6.5% and (5) faults with an AHP weight of 3.7%, for which a radius of consistency of 1.9% (1.9% <10%) was obtained. A susceptibility map based on the established weights for the variables was constructed. The following distribution of surface by susceptibility value was found: (1) Surface in high susceptibility, 30.32%; (2) surface in medium susceptibility, 39.84% and (3) surface in low susceptibility, 29.84%. The distribution of documented mass movements for the studied region was observed, finding 52.63% of the total landslides on high susceptibility surfaces; 43.86% on medium susceptibility surfaces and 3.51% on low susceptibility surfaces. Spearman coefficients were calculated that determined a strong correlation (rho = .98, S = .50362, p = .0003091) between the susceptibility level calculated by the model and amount of landslides in the study area.