LANDSLIDE INVENTORY, DENSITY AND HAZARD MAPS: A COMPARISON

Cardinali M.¹, Carrara A.², Guzzetti F.¹, and Reichenbach P.¹ 1 - CNR-IRPI, Perugia, Italy
2 - CNR-CSITE, Bologna, Italy

Cartography is a crucial aspect of any landslide hazard assessment. Landslide maps most commonly prepared by geomorphologists are: landslide inventories; landslide density maps; and landslide hazard maps. Their purpose is to visualise the spatial distribution of landslides and to portray the associated hazard. Landslide maps can be prepared by a variety of methods depending on the scope, the available resources and the scale. Inventories are the simplest form of landslide mapping. They record the location of all landslides that left discernible features in the area. They may show the type of failure and the date of occurrence. Density maps are obtained by interpolating (in space) the information available from landslide inventories. Proper interpolation must be guided by geomorphologic constrains. Hazard maps show the distribution of landslide hazard inferred by direct mapping or thorough indirect, qualitative or quantitative modelling. Examples of different landslide maps prepared for the Umbria-Marche region of Central Italy are used to discuss the information content and reliability of landslide maps. In the attempt to limit the drawbacks inherent in any type of landslide map, and in order to maximise their information content, combination of different landslide maps are proposed and discussed.