Use of Landslide Maps and Models

The value of a map refers to its information content, which depends on the type of data shown, their quality and the extent to which the information is new and essential. A map is valuable when the data shown are useful to the user, i.e., when the map is both relevant and understood by the user (Guzzetti et al., 2000). A carefully designed inventory map that shows landslides as recognised by the interpreter, without any modification apart from scale or graphical constrains, is a basic map. A landslide density map obtained by interpolating an inventory map without any additional information is a derivative map. Landslide susceptibility and hazard maps obtained from an inventory are also derivative maps but, since they include additional information on factors such as lithology and morphology that are used to build the susceptibility or hazard models, they have an information content which is superior to that of the input maps, including the inventory. Risk assessments are complex, high level products that exploit basic, derivative and other thematic information and maps (Guzzetti et al., 2000). In this chapter, I first describe and compare the information content of different landslide cartographic products, including inventory, density, susceptibility and hazard maps, and risk evaluations. Next, I introduce and discuss the concept of a “landslide protocol”, i.e., a set of regulations established to link terrain domains shown on the different landslide maps to proper land use rules. ...