A comparison between natural and Head/tail breaks in LSI (Landslide Susceptibility Index) classification for landslide susceptibility mapping: A case study in Ponorogo, East Java, Indonesia

The most common method is used and claimed excellent in statistical mapping is Jenk's Natural Breaks, while Head-tail Breaks is a new classification method, this method also is claimed to be the best in classifying data with a heavy-tailed distribution. Landslide is one of the disasters that often occur in Indonesia. In Ponorogo, East Java has a landslide susceptibility area that is not balanced. Most of the area was never had landslide and only a small area frequently had landslide per year, the landslide data occurrence has similarity with heavy-tailed distribution. Nevertheless the number of both fatalities and loss of material is not little. To reduce the losses, this study propose classification mapping for landslide susceptibility area using Natural Breaks and Head/tail Breaks, and compare the both of result classification method to get the best landslide hazard map. Classification consists of high susceptibility area, moderate susceptibility area, low susceptibility area and very low susceptibility area. Classification results using both Natural Breaks and Head/tail Breaks are validated by using Pearson Chi-Square test, and significant value of Natural Breaks (184.9166) is higher than Head/tail Breaks (105.5885). So Natural Breaks is considered better than the Head/tail Breaks in this case.