en ru 
Slope gradient is an angle between the tangential and horizontal
planes at a given point of the topographic surface*. The unit
of measurement is degree. Once elevations are given by , where x
and y are plane Cartesian coordinates, slope gradient is a function
of the partial derivatives of z: , where and . Slope
gradient determines the velocity of gravitydriven flows. Like
other local morphometric variables, slope
gradient can be derived from a digital
elevation model (DEM) by a universal spectral
analytical method as well as finitedifference methods (e.g., method 1, method 2, and method 3). Example**. A model of slope gradient was derived from a
DEM of Mount Ararat by the
universal spectral analytical method.
The model includes 779,401 points
(the matrix 1081 x 721); the grid spacing is 1". The vertical
exaggeration of the 3D model is 2x. The data processing and modelling were carried out using the software Matlab R2008b. References
*
Shary, P.A., 1995. Land surface in gravity points classification by a
complete system of curvatures. Mathematical Geology, 27 373390.
** Florinsky,
I.V., 2016. An illustrated introduction to geomorphometry. Almamac Space
and Time, 11 (1): 20 p. (in Russian, with English abstract). Article
at the journal website
For
details and other examples, see:
