Rainfall induced landslide susceptibility mapping
Landslide risk maps at a regional scale.
The method (Nadim et al., 2006) is used to identify the global distribution of landslide hazards and risks. It uses existing global databases freely available online and classifies areas according to the hazard level. The elements exposed are overlapped with hazard maps in a GIS environment to build risk maps (i.e., hotspots). Quantification of the elements exposed is also made.
To identify the global landslide hazard and risk "hotspots," Nadim et al. (2006) adopted a simplified first-pass analysis method. The scale of the analysis is a grid of roughly 1km x 1km pixels where landslide hazard, defined as the annual probability of occurrence of a potentially destructive landslide event, is estimated by an appropriate combination of the triggering factors (mainly extreme precipitation) and susceptibility factors (slope, lithology, and soil moisture).
The weights of different triggering and susceptibility factors are calibrated to the information available in landslide inventories and physical processes (Figure 1).
Figure 1: Schematic approach for landslide hazard and risk evaluation (Nadim et al. 2006).
The landslide hazard indices were estimated using the following equations:
Hr = (Sr × S1 × Sv) × Tp
where
- Hr is the landslide hazard index for rainfall-induced landslides
- Sr is the slope factor within a selected grid
- Sl is lithological (or geological) conditions factor
- Sv is the vegetation cover factor Tp is the precipitation factor
Landslide hazard map Italy
Upcoming improvements/future services
Precipitation-induced landslides hazard (software, web portal, training)
This service provides a tool to generate dynamic hazard maps in user-defined areas for rainfall-induced landslides. The maps change as a function of the rainfall inputs provided by the user. The maps are built by combining the susceptibility classes (9.6 GB of data, shared via zenodo) of the specified areas with the rainfall scenarios. Different susceptibility classes are defined on the basis of slope, lithology, land cover and average rainfall scenarios (calculated for current climate - W5E5 and a future scenario - SSP126). The combination of susceptibility classes and rainfall intensity inputs, provided by the user, produce the hazard map. This service therefore provides a dynamic hazard mapping based on rainfall intensity as an input. The hazard maps can be generated for any region of the world.
Github repository that contains the codes for the Geo-INQUIRE tool to compute the rainfall-induced landslide hazard over an area.
Dataset of global rainfall-induced landslide susceptibility maps developed using Global Infrastructure Resilience Index (GIRI) model.
References
- Farrokh Nadim, Christian Jaedicke, Helge Smebye, Bjørn Kalsnes (2006). Assessment of global landslide hazard hotspots. International Centre for Geohazards (ICG) / Norwegian Geotechnical Institute (NGI), Oslo, Norway. IPL Project C102
Precipitation-induced landslide hazard is one of the services included in the GEO-INQUIRE Virtual Access to products enabling curiosity-driven science for geohazard and multi-risk assessment
(see https://www.geo-inquire.eu/virtual-access/geohazard-and-multi-risk-assessment for details).
