en ru
|
Slope
aspect is an angle between the
northern direction and the horizontal projection of the two-dimensional
vector of gradient counted clockwise at a given point of the topographic
surface*. The unit of measurement is degree. Once
elevations are given by . where x and y are Cartesian
co-ordinates, slope aspect (A) is a function of the partial
derivatives of z: , where
and . Slope
aspect is a measure of the direction of gravity-driven flows. Like other local morphometric
variables, slope aspect can be derived from a digital elevation model (DEM) by finite-difference
methods (e.g., IF-2009
method and IF-1998
method) as well as the universal spectral
analytical method. Example**. A model of slope aspect 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: 373–390.
** Florinsky,
I.V., 2017. An illustrated introduction to
general geomorphometry. Progress in Physical Geography, 41:
723–752. doi pdf
For
details and other examples, see:
|