Landslide processes and Andosols: the case study of the Campania region, Italy.

Most catastrophic mudslides in Campania are related to soils developing upon pyroclastic materials covering carbonatic relieves of the Campanian Apennines. The soil observed in the detachment crowns of the investigated fast mudflow consisted of fertile Andosols (generally Hapludands and Udivitrands) that were very sensitive to anthropic or natural changes. This is due to the unique chemical, physical, morphological and hydrological behaviour of these soils, including (i) high water retention near saturation, (ii) high hydraulic conductivity, (iii) high smeariness of most horizons, and (iv) high vertical and lateral variability of the properties of the soil horizons. Aspect is important in determining soil susceptibility to landslide triggering and landslide susceptibility is related to hydrological properties that induce higher water storage especially in northern aspect soils. It is clear that stability of these soils requires conservation, implemented through appropriate forest planning and management. Improved risk management policies are necessary to preserve soil continuity and to decrease the risk both of surface soil erosion and to human lives and infrastructure. [ABSTRACT FROM AUTHOR]