RISK ASSESSMENT METHODS OF LANDSLIDES

Landslides in Europe mainly occur in Alpine regions and are related to the erosion-prone areas. Landslides in topsoils, also referred to as ‘Blaiken ’ or shallow landslides (Maquaire & Malet, 2006), are caused by a set of preparatory and triggering factors which determine their location, their frequency and their magnitude. Apart from relief, geology, hydrology and climate, the geomorphological changes in connection with land use, as well as vegetation and soil changes may influence landslides in cultural landscapes. Effect of forest vegetation (and particularly the role of the architecture, morphology and properties of roots) on soil fixation, erosion, and water-flow has been measured, modelled and integrated in DSS in EU-funded projects recently (Tasser, 2003). Our limited understanding of the variability of the causes and consequences of landslides and their transient characteristics limits our ability to forecast shallow landslides with mathematical, process-based, models. Consequently, available landslide RAMs are diverse and combine expert judgment, empirical approaches and to a lesser extent mathematical simulations. A trend in harmonizing procedures and proposing standards is nevertheless gaining ground since the execution of various EU-funded projects, though differences in terminology often hamper exchanges of information. The following study initiated within the framework of the RAMSOIL project concerns the landslide threat which is one of the degradation processes of the soils