Analysis of the influence of land use on the runout area of shallow landslides

Abstract

<p>According to the Centre for Research on Epidemiology of Disasters, every year landslides are to be blamed worldwide for at least 17% of all fatalities from natural disasters. Rainfall-induced shallow landslides are responsible for a significant number of those: they mobilize the first few meters (usually <2m) of soil, have high velocities and occur after abundant and prolonged rainfall events.</p><p>The runout of a landslide, defined as the difference between the total area of a landslide and its source area, from which the sediment is first mobilized, is what determines how far a landslide travels and how big the affected area is, and yet the runout is often neglected when it comes to analysing the overall hazard caused by potential landslides.</p><p>The land use practices have been proven as one of the factors which impact the susceptibility of an area to the formation of shallow landslides, it is however less clear if the land use also plays a role in influencing the size of the area of runout.</p><p>The aim of the present work is to investigate the correlation between the runout area and the land use in which the shallow landslide develops.</p><p>To do so, two inventories of landslides, which occurred in neighbouring regions in Northern Italy (Lombardy and Piedmont), comparable for lithology, land use, geomorphology and climate, were analysed.</p><p>The result of the analysis was that there were statistical differences in the distribution of the runout among different land use classes, meaning that an influence of the land use on the runout was highly probable. Such results could improve the comprehension on shallow landslides mobility and runout and could lead to the development of possible models of assessment of the runout at different scales.</p>