Estimates the gradient in each site, defined as the module of the gradient vector.
It is possible to choose between different formulas to calculate the gradient and to define if the output map values should be in tangent of the angles or in degrees.
Inputs
- the file containing the matrix of elevations (the DEM or the map obtained with pitfiller)
Output
- file containing the matrix of the gradients
Notes
Let's observe that gradients, contrarily to slope, does not use the drainage directions defined by DrainDir or FlowDirections. Moreover, Gradients calculates only the module of the gradient which in reality is a vectorial quantity, oriented in the direction from the minimal to the maximal potential.
As a rule, the program places on
the catchment boundary the gradient equal to zero.