Generates a Flow Direction raster in which each cells represents the direction of flow for this cell in the DEM
using the D8 method.
Inputs:
Input DEM raster dataset
Output raster name and format
Outputs:
An integer raster representing the Flow Direction according to the
D8 (Deterministic 8) method. The 8 flow directions are coded with values 1,2,4,8,16,32,64,128 and
value of 0 indicates an outlet. The values are coded using the following convention:.
For example if the steepest descent of a cell is to the left, its Flow direction
will be coded as 1, if it is to upper right, it will be coded as 32.
The steepest descent is calculated by dividing the elevation difference by the
distance between the cell centers.
Example:
An example of Flow Direction D8 output.
Notes:
The Flow direction values are determined based on the steepest downslope neighbor for each cell.
If a cell is lower than its 8 neighbors it is assigned a value of 0 meaning it is an outlet or sink.
If a cell has the same slope in more than one direction, the first encountered direction is assigned.
