Some preferences can be defined under the menu Options > Preferences:
Options for data storage
Split data in rows of x meters: There is normally no need to change this parameter. You can reduce this value only if you have memory issues when formatting data (default: 1000).
Ratio for DEM overview: You can change this value when the display of the DEM is not adapted (default: 10).
Options for the processing
Number of threads to use: You can choose how many threads Flow-R can use. You can set -1, which let Matlab choose (default: -1).
Susceptibility threshold: The susceptibility threshold has a significant impact on the processing time, but also on the resulting extent. Please check the reference paper for more information (default: 0.0003).
Allow reordering of the active cells: This option should be more efficient in terms of processing time, and do not change the results (default: yes).
KML (Google Earth) output options
Enable KML output: KML exporting is experimental and does not work well for every place in the World. In some locations, a shift can exist in between the results and the terrain. Moreover, it is very time consuming (default: no).
Layer opacity: Opacity of the generated KML layer (default: 90).
Color factor for susceptibility: Adjustment of the colors for the susceptibility (default: 3).
Color factor for energy: Adjustment of the colors for the energy (default: 1).