An integrated approach to the study of catastrophic debris-flows: geological hazard and human influence

Abstract

Abstract. On 1 October 2009, a prolonged and intense rainstorm triggered hundreds of landslides (predominantly debris flows) in an area of about 50 km 2 in the north-eastern sector of Sicily (Italy). Debris flows swept the highest parts of many villages and passed over the SS114 state highway and the Messina-Catania railway, causing more than 30 fatalities.This region has a high relief, due to recent uplift. The peculiar geological and geomorphological framework represents one of the most common predisposing causes of rainstormtriggered debris flows. This paper deals with the geological and hydro-geomorphological studies performed as a part of the post-disaster activities operated in collaboration with Civil Protection Authority, with the aim at examining landslides effects and mechanisms. The data were elaborated into a GIS platform, to evaluate the influence of urbanisation on the drainage pattern, and were correlated with the lithological and structural framework of the area.Our study points at the evaluation of the volume involved, the detection of triggering mechanisms and the precise reconstruction of the influence of urbanisation as fundamental tools for understanding the dynamics of catastrophic landslides. This kind of analysis, including all the desirable approaches for the correct management of debris flow should be the starting point for robust urban planning.

Spaceborne, UAV and ground-based remote sensing techniques for landslide mapping, monitoring and early warning

“…In image fusion procedures, multispectral channels, characterized by a coarser spatial resolution than the panchromatic, are downscaled through analytical models based on the panchromatic-derived spatial information (Eyers et al, 1998;Chini et al, 2011;Martha and Kerle, 2012;Kurtz et al, 2014). The False Colour Composites (FCCs) of the VHR images are often used to discriminate lithologies or terrain having different characteristics (weathering, water content, vegetation cover) (Ciampalini et al, 2012;Lamri et al, 2016).…”

“…2), in which the geological features are characterized by the typical features of recently uplifted areas, developed on a crystalline basement with steep slopes and shallow clayey soil cover. In the late afternoon of October 1 st 2009, an intense storm affected the area between the Peloritani Mountains ridge and the Ionian coastline Del Ventisette et al, 2012), where the main villages are located. During the same night, the persisting rainfall triggered more than 600 landslides, such as shallow soil slides and debris flows, on an area of about 50 km 2 .…”

“…During the same night, the persisting rainfall triggered more than 600 landslides, such as shallow soil slides and debris flows, on an area of about 50 km 2 . The assessed number of fatalities caused by landslides and inundation was 37 (including 31 deaths and 6 missing persons), with 122 injured people and 2019 evacuated people (Ardizzone et al, 2012;Del Ventisette et al, 2012;Raspini et al, 2013); the worst damages were reported in the village of Giampilieri (Fig. 2).…”

Evaluation of shallow landslide-triggering scenarios through a physically based approach: an example of application in the southern Messina area (northeastern Sicily, Italy)

“…During these events, several landslides were triggered in Scaletta Marina and Giampilieri, convincing the authorities to declare a state of natural disaster for the villages of the southern Messina area. However, even though the increase of recorded events during the last 20 years also depends on the increasing number of sources of information, it is important to emphasize that, in the same period, the landslide risk exposure of the area increased substantially due to the enlargement of the urban area as a consequence of poor land-use planning (Del Ventisette et al, 2012). Finally, recent studies (Bonaccorso et al, 2005;Arnone et al, 2013) indicate an increasing trend of extreme, short-duration rainfall events over the last few decades in Sicily, especially in coastal areas.…”

Exploitation of Large Archives of ERS and ENVISAT C-Band SAR Data to Characterize Ground Deformations

“…In the period from October 2009 to February 2010, the Nebrodi area (Messina Province) was highly affected by severe storms that triggered several landslides causing intense damage to structures and infrastructure with some casualties [41,42]. In the official landslide inventory maps (IFFI and PAI; both updated in 2004), several landslides are mapped in the San Fratello area (Figure 4).…”