Nepal Landslide Potential Model

Map depicting model data representing qualitative landslide potential over Nepal. Ranks range from 1 (lowest potential) to 10 (highest potential). The baseline model is a static model giving ranks based on similarity to areas where landslides are known to occur. The key assumption is that terrain and surface characteristics that occur most frequently in known landslide areas can be used as indicators of potential landslide hazard in other areas. The input characteristics are soil type, landcover, slope, and climate regime. Pixels that are more similar to known landslide hazard areas are assigned higher ranks to form the baseline hazard model. Daily precipitation adjusted potentials represent increase in potential due to presence of precipitation, a key landslide trigger. The models are generated by determining areas where precipitation over the previous two week period have exceeded statistical thresholds and the baseline rankings in these areas are adjusted upwards to account for the increased landslide potential due to rainfall. Landslide Indicators layers represent areas where the potential for landslides has increased due to precipitation triggers. Values are calculated by finding the increase in potential rank between the baseline model and the precipitation adjusted model. The indicators layers are useful in determining where landslide potential is increased independent of the actual potential ranking.