In order to appropriately analyse these parameters within the MCE model, the following raster factors were normalized using Spatial Analyst Tool > Map Algebra> Raster Calculator:
- Slope;
- Precipitation; and
- Proximity to fault lines.
Values were normalized between a range of 0 to 1; 0 indicating no landslide susceptibility, and 1 indicating the highest susceptibility to landslides. The following equation was utilized in order to normalize each raster layer using the Raster Calculator function:
(Parameter value – Minimum parameter value)/(Maximum Parameter value – Minimum Parameter value)
This equation was utilized unaltered for slope and precipitation because as these parameters increased, the probability of landslide occurrences in this area also increased. However, because landslide occurrence decreased with increased distance from fault lines, the following inverse equation was applied to the “proximity to fault lines” raster layer:
1 – (Parameter value – Minimum parameter value)/(Maximum Parameter value – Minimum Parameter value)