Methodology

The methodology applied to build up the Italian Landslide Inventory is based on aerial photo-interpretation, historical documents and field surveys. In order to homogenize and integrate the landslide data for the whole Italian territory the Landslide data sheet has been defined on the basis of International standards of classification.

Aerial photo-interpretation is extremely useful for mapping landslide boundaries over large study areas, allowing the identification of the main landslides

Historical and archive data

Historical documents and archive data allow the reconstruction of landslide past events and the evaluation of recurrence interval.

Field surveys: Field surveys are very useful to validate photo-interpretation and update information about landslide geometry, type, lithology, activity, causes, damage. Those data are essential to fill the Landslide data sheet.

Landslide data sheet: Information on each landslide has been collected using the IFFI Landslide data sheet organised in three distinct information levels:

the 1st level contains the basic data on landslide location, type of movement and state of activity;

the 2nd level provides data on morphometry, geological setting, lithology, land use, causes of activation, date of activation;

the 3rd level gives detailed information on damage, investigation process and remedial measures for risk reduction.

For a complete description of the Landslide Sheet, see the available Guidelines.

The IFFI inventory contains vector layers of landslides and an alphanumeric archive of attributes analyzed in Italy.

On most of the national territory the scale adopted for mapping of landslides is 1: 10.000 and 1: 25.000 in mountain or poorly populated areas.

Alphanumeric database: the logic structure of the database is based on the IFFI Landslide data sheet.

Cartographic database: Landslides are represented as a:

georeferenced point, located at the highest point of the crown;

polygon when the landslide area is >10,000 square meters;

line when the width is very narrow, as in the case of debris flows.

The landslides are classified by type of movement and level of detail of the IFFI Landslide data sheet.

Landslide ID: The landslide ID is a code whose values uniquely identify each landslide over the whole Italian territory. This code links the alphanumeric attributes to the geographic features.