The Cercevesa Valley landslide, located in Paularo, Friuli Venezia
Giulia at an altitude of 1100-1600 m, is one of the fastest largescale
mass movements in rock slope currently active along the
Alps. The mountainside is characterized by a sequence of
Devonian tentaculata limestones overlying Hockwipfel Formation
sandstones. Landslides movements started in 1990-1992 and the
most evident morphological feature was the opening of a crestal
trench that has an actual offset of 20 m and a total length of 600
m. Nowdays the features is clearly identifiable from satellite
viewers. Since 2011 many small rockfalls occured rolling over the
steep slope towards the Cercevesa River. The Friuli Venezia Giulia
Geological Survey started monitoring the area from 2008;
spreading trench measures have been acquired in nine different
sites by laser distance meter and three GPS benchmarks have
been installed by Univ. Trieste and OGS. Several
photogrammetric flights and one helicopter laser scan acquisition
have been compared: the average movement rate is about 80
cm/year. The trench reveals a higly consistency opening rate with
linear correlation coefficient r= 0.998-1.000. Kinematics is not
sensitive to seasonel changes: rain, snowmelt and the freezing of
the ground surface that in the area reduces water infiltration.
There have been considered several different triggering factors in
time span 1990-1992: the 1990 mid-november rainfall was the
only relevant one. It also has been analysed how the effect of
the last century snow level reduction, occurred during Autumn’s
months, can have helped the triggering factor.
