Landslides and climatic conditions in the Barcelonnette and Vars basins (Southern French Alps, France)

Analysis of a landslide multi-date inventory in a complex mountain landscape: the Ubaye valley case study

“…Considering the timing of annual tree ring formation at Bois Noir, landsliding is likely to have occurred in 1874-1875, 1896-1897, 1946-1947, 1992-1993(Lopez-Saez et al, 2011. According to Lopez-Saez et al (2012), the Pra Bellon landslide had no relevant reactivation for the period 1980-1990, while the La Valette landslide has been triggered in 1982 and major failures were observed at Super-Sauze between 1978 and 1982 (Flageollet et al, 1999;Malet, 2003). Figure 13 indicates that many reactivations were recorded at the Bois Noir landslide for the year 2004, but only a few landslides are recorded elsewhere in the region.…”

“…Numerous studies were conducted for the analysis of mass movements (Flageollet et al, 1999;Malet et al, 2005a;Maquaire et al, 2003;Razak et al, 2011;Remaître et al, 2005;Thiery, 2007;Thiery et al, 2014) and several landslide types were mapped and analysed along the slopes (Fig. 1a).…”

Airborne laser scanning : for forested landslides investigation in temperate and tropical invironments

“…This forested catchment is situated in the dry intra-Alpine zone, and is characterized by strong interannual rainfall variability. (Flageollet et al, 1999). Maquaire et al (2003) reported that the mean annual temperature is 7.5 0 C with 130 frost days per annum.…”

“…Geologically, the northern part of Bois Noir is characterized by morainic colluvium and autochthonous Callovo-Oxfordian unstable black marls, overlaid by deposits of reworked glacial till. The area is highly affected by landslides (Flageollet et al, 1999;Maquaire et al, 2003). The southern part of Bois Noir is characterized by outcrops of limestone in the summit crest and features steep slopes of up to 70 , with extensive scree slopes.…”

“…The hummocky topography is inherited from the different phases of the Quaternary glaciation (Hippolyte and Dumont, 2002). Flageollet et al (1999) stated that the slope instability is controlled by the climatic conditions. Instability is likely to occur after heavy rainfall following a relatively dry period.…”