Landslide movements triggered by rainfall can be foreseen in real-time
by modelling the relationship between rainfall amount and landslide o
ccurrence. This paper deals with the problem of the reliability of the
FLaIR (Forecasting of Landslides Induced by Rainfalls) model when app
lied to forecasting landslide movements in the usual condition of poor
historical information availability. In this case, the identification
of the admissibility field for the model parameters, instead of a poi
nt estimation, leads to an improvement of the forecasting reliability.
Moreover, this approach makes the model capable of taking into accoun
t information embodied in periods of heavy rain but without movement.
The concepts of informative content and foreseeability of landslide mo
vements are introduced and their duality is analyzed. The effectivenes
s of the estimation procedure described has been tested by application
on two landslides located in southern Italy.