Select "Data Preparation->Terrain Partition". Specify the parameters and the output file.
Output: Terrain Partition
Divide the terrain into slope partitions.
Coded Streamlines
The streamlines data of the area, which can be generated by "Streamline" modular in "Data Preparation".
Flow Direction File
The flow direction data generated by "Flow Direction" modular in "Data Preparation".
Combine partitions with similar aspect: angle <
If the difference between the two partitions is less than the value, combine them.