Suchergebnisse

Abstract. The Liguria coastal region in Italy was affected by two heavy rainfall episodes and subsequent severe flooding that occurred at the end of October and the beginning of November 2011. In both cases, the very large accumulated precipitation maxima were associated with intense and quasi-stationary convective systems that developed near the coast, both related to orographic lift and similar low-level mesoscale flow patterns over the Ligurian Sea, giving rise to pronounced convergence lines. This study aims at analysing the main dynamical processes responsible for the onset, lifecycle, intensity and localisation/propagation of the precipitating systems, using the ISAC convection-permitting model MOLOCH applied at different spatial resolutions and comparing model output fields with available observations. The ability of the model in quantitative precipitation forecasting (QPF) is tested with respect to initial conditions and model horizontal resolution. Although precipitation maxima remain underestimated in the model experiments, it is shown that errors in QPF in both amount and position tend to decrease with increasing grid resolution. It is shown that model accuracy in forecasting rainfall amounts and localisation of the precipitating systems critically depends on the ability to represent the cold air outflow from the Po Valley to the Ligurian Sea, which determines the position and intensity of the mesoscale convergence lines over the sea. Such convergence lines controls, together with the lifting produced by the Apennines chain surrounding the coast, the onset of the severe convection.

Abstract. In recent decades, the Entella River basin, in the
Liguria Apennines, northern Italy, was hit by numerous intense rainfall
events that triggered shallow landslides and earth flows, causing casualties
and extensive damage. We analyzed landslide information obtained from
different sources and rainfall data recorded in the period 2002–2016 by
rain gauges scattered throughout the catchment, to identify the event rainfall
duration, D (in h), and rainfall intensity, I (in mm h−1), that
presumably caused the landslide events. Rainfall-induced landslides affected
the whole catchment area, but were most frequent and abundant in the central
part, where the three most severe events hit on 23–24 November 2002,
21–22 October 2013 and 10–11 November 2014. Examining the timing and location of
the slope failures, we found that the rainfall-induced landslides occurred
primarily at the same time or within 6 h from the maximum peak
rainfall intensity, and at or near the geographical location where the
rainfall intensity was largest. Failures involved mainly forested and
natural surfaces, and secondarily cultivated and terraced slopes, with
different levels of maintenance. Man-made structures frequently characterize
the landslide source areas. Adopting a frequentist approach, we define the
event rainfall intensity–event duration (ID) threshold for the possible
initiation of shallow landslides and hyper-concentrated flows in the Entella
River basin. The threshold is lower than most of the curves proposed in the
literature for similar mountain catchments, local areas and single regions
in Italy. The result suggests a high susceptibility to rainfall-induced
shallow landslides of the Entella catchment due to its high-relief
topography, geological and geomorphological settings, meteorological and
rainfall conditions, and human interference. Analysis of the antecedent
rainfall conditions for different periods, from 3 to 15 days, revealed that
the antecedent rainfall did not play a significant role in the initiation of
landslides in the Entella catchment. We expect that our findings will be
useful in regional to local landslides early warning systems, and for
land planning aimed at reducing landslide risk in the study area.

The contribution analysis the effects of digital transformation, provides a critical assessment of the policies on e-government in Europe and in Italy, and draft a research agenda focused on Liguria Region. The article moves from the need to conduct research aimed at analyzing the change in the relations between subject and institution in contemporary western societies. The article, focusing on official documents, explores the strategies of digital transformation adopted by the EU. Liguria is a case study of interest because, starting from the 2016-2018 Digital Strategic Program, has adopted a strong focus on the principles of Open Government and an explicit decision to invest in specific digital services for citizens and businesses.