Shallow-landslide susceptibility in the Costa Viola mountain ridge (southern Calabria, Italy) with considerations on the role of causal factors

摘要: The “Costa Viola” mountain ridge (southern Calabria), in the sector between Bagnara Calabra and Scilla, is particularly exposed to geo-hydrological risk conditions. study area has repeatedly been affected by slope instability events last decades, mainly related debris slides, rock falls flows. These types of movements are among most destructive dangerous for people infrastructures, characterized abrupt onset extremely rapid movements. Susceptibility evaluations shallow landslides have performed only focusing on source activation. A logistic regression approach applied estimating presence/absence sources terms probability, basis linear statistical relationships with a set territorial variables. An inventory map 181 sources, obtained from interpretation air photographs taken 1954–1955, used as training set, another 81 extracted 1990 1991 photographs, adopted validation purposes. initial 12 variables (i.e. lithology, land use, soil sand percentage, elevation, angle, aspect, across-slope down-slope curvatures, topographic wetness index, distance road, fault index daily rainfall) considered. procedure consists following steps: (1) parameterization independent variables, (2) sampling, (3) calibration, (4) application (5) evaluation forecasting capability. “best set” could be identified iteratively excluding one variable at time, comparing ROC results. Through sensitivity analysis, role considered factors predisposing failures evaluated. results Costa Viola can acceptable, 98.1 % cells correctly classified. According susceptibility map, village Scilla its surroundings fall highest class.