Landslides are among the most important, natural or man-induced, gravity-controlled processes and represent one of the most widespread geological hazards worldwide. They cause variable impacts and damage on man-made infrastructures and facilities, depending on the type of processes, the involved materials and their velocity. As earthquakes, landslides have catastrophic effects with consequent fatalities and high socio-economic damage to man-built structures and great direct and indirect associated costs. The investigation of slope instability, mainly in urban areas affected by landslides, is an important issue for mitigation planning and landslide risk management. Physical vulnerability, that includes the definition of the degree of damage on lifelines and buildings, is an important parameter in risk estimation.
The investigation, recognition and classification of landslide-induced damage can be fostered for several reasons, such as administrative (to promulgate restrictive rules), planning (to make decisions on restoration or relocation of damaged structures), scientific (to improve of the knowledge of the effect of the landslide on structures and infrastructures) and engineering design (to agree a reconstruction plan). The surveying and classification of landslide-induced damage play a key role in the strategy to better delineate mass-movement boundaries by identifying its detectable impacts on the ground. In addition this procedure has impacts on the improvement of knowledge of the instability, to help avoid similar occurrences and the planning of mitigation measures. Moreover, the assessment of the level of damage affecting facilities is useful also to set countermeasures for avoiding future losses.