Field monitoring and laboratory results are presented for an unsaturated
volcanic pyroclastic. The pyroclastic is constantly affected by intense
erosion, collapse and liquefaction. The pyroclastic can also move as an
undisturbed block of material (a combination between fall and of
topple), sand/silt/debris flowslide and debris avalanche during the
rainy season or earthquakes. This type of material and the uncontrolled
urbanization aggravate the environmental, social and economic damages of
the region. Most of the slopes are almost vertical and temporally
stable, but will collapse when wetted or during seismic events. Wetting
of the soil is likely to occur following construction development,
because evaporation is reduced by covering the ground surface with a
structure. Is possible to conclude that not only climatic factors as
rain quantity, temperature and evaporation are important into landslide
susceptibility but also information of suction-moisture content,
seepage, topography, weathering, ground deformation, vibrations, cracks,
vegetation/roots and the presence of crust covering the surface are
necessary to research in each site.