To calculate Landslide Risk, we use the following data:
Landslide Risk is calculated considering that landslides can be triggered by two main causes: earthquakes and intense precipitation (as described in The Global Landslide Hazard Map). The methodology separately assesses these two hazards and final risk for a given year is determined by the maximum value between the two.
Earthquake-Triggered Landslide Risk This risk is static and based on combination of:
Rainfall-Triggered Landslide Risk This risk is dynamic and calculated for each future year using a Machine Learning model (Random Forest) trained on historical landslide and rainfall data. The model predicts, for each day of the year, whether conditions are favorable for a landslide. Variables used are:
Final risk level is maximum between seismic (static) and rainfall (annual) risk.
The methodology described for Landslide Risk assessment is a multi-hazard approach. This method correctly recognizes that landslides are complex processes triggered by different factors (earthquakes and rainfall), and uses specific and validated models for each trigger type.
The idea of combining a static susceptibility map with dynamic triggers (rain, earthquake) is the foundation of modern landslide hazard mapping.
In conclusion, our methodology is a synthesis of best scientific practices. It correctly separates the two main physical triggers (earthquake and rain), uses authoritative global susceptibility data (NASA), and applies for each trigger a scientifically validated sub-model.
The methodology described for Landslide Risk assessment is a multi-hazard approach. This method correctly recognizes that landslides are complex processes triggered by different factors (earthquakes and rainfall), and uses specific and validated models for each trigger type.
The idea of combining a static susceptibility map with dynamic triggers (rain, earthquake) is the foundation of modern landslide hazard mapping. • A global landslide catalog for hazard applications: method, results, and limitations — This work describes creation of NASA's 'Global Landslide Catalog' and discusses the need to model landslide triggers (particularly rain) on a global scale. • A heuristic approach to global landslide susceptibility mapping — This paper describes the methodology behind creating NASA's global landslide susceptibility map. • Global landslide and avalanche hotspots — This pioneering study, conducted by the Norwegian Geotechnical Institute (NGI), developed the first global model to estimate earthquake-triggered landslide hazard. • The rainfall intensity-duration control of shallow landslides and debris flows: an update — It scientifically demonstrates that landslides are not caused only by rainfall on a single day, but by combination of rain intensity and its duration, and especially by soil saturation due to antecedent rainfall. • Satellite-Based Assessment of Rainfall-Triggered Landslide Hazard for Situational Awareness — This paper describes NASA's operational model called LHASA (Landslide Hazard Assessment for Situational Awareness).
In conclusion, our methodology is a synthesis of best scientific practices. It correctly separates the two main physical triggers (earthquake and rain), uses authoritative global susceptibility data (NASA), and applies for each trigger a scientifically validated sub-model.