Description
The main landslides are located in phylladic, werfenian siltstone and Eocene marlstone formations, as well as in Quaternary loose deposits. The most frequent disruptions are those in the form of mudflows or debris flows and rock mass collapses.
The primary cause of landslides is the natural geomorphological evolution of the territory, which manifests itself on the one hand with the degradation of the reliefs and on the other with the filling of depressions with continuous movements of masses, both vertical and tangential, in order to reach equilibrium.
Other types of landslides are linked to the high degradation of certain lithotypes, which leads to the creation of eluvial clayey layers. The latter may be affected by landslide phenomena, even on slopes with a weak inclination, due to the poor geotechnical characteristics of the materials. Collapsing or sliding landslides are also frequent, particularly in the outcrop areas of calcareous-dolomitic, porphyritic and granitic rocks, either of recent age or produced in very ancient times.
The causes of these phenomena are many: lithological, tectonic and stratigraphic discontinuities, freeze-thaw, karst dissolution and, last but not least, telluric tremors.
Among the causes of the increase in the frequency of landslide phenomena, anthropisation, with its associated disruption of the natural balance, is gaining in importance. In fact, the depopulation of some mountain areas, the concentration of settlements in poles and the expansion of the road network, which on the one hand has deprived large areas, now in a phase of rapid degradation, of the control and maintenance action, on the other hand has created areas and centres that are more vulnerable because they are too densely anthropised, increasing the direct and indirect costs of preventing landslides.
A brief illustration of the situation of the Trentino territory shows its potential vulnerability. In order to prevent landslides, it is therefore necessary to know their location, the mechanisms of movement, their causes and to identify possible remediation measures.