A National Warning System for Rainfall-Induced Landslides in Slovenia

In Slovenia intense short and less intense long-duration rainfall is a primary cause of shallow landslides that some estimates put at 10,000, or approximately one landslide per two square kilometres. These events impose a huge burden on local and state budgets, occasionally even taking lives. At least part of the damage (and the loss of lives) could be prevented with a reliable near real-time landslide hazard forecast system that would continuously draw from three data/model pillars: the precipitation forecast model, the landslide susceptibility model and the rainfall triggering values for landslide occurrence. Each of the three pillars brings some uncertainty to the landslide hazard forecast. A project was set up to forecast the possible occurrence of rainfall-induced landslides in Slovenia (acronym “Masprem”), tackling all three pillars, but focusing primarily on the rainfall triggering values. With the goal of an automated near real-time landslide hazard forecast that will eventually be promptly available online to the general public, the challenges of precipitation forecast data conversion and transfer between two servers, continuous forecast model development and serving the intermediate forecast results on the web were dealt with. The project set up a challenging task, to model the landslide hazard through time for the whole of Slovenia at a coarser scale and to model the same hazard for selected municipalities at a more detailed scale. The results and lessons learned will be presented in this paper.