plancurv¶

plancurv

Planform curvature calculation using a DEM

Result = plancurv(dem)
dem

spatial scalar

Result

spatial scalar

Options¶

--unittrue

horizontal and vertical scale is measured in true distance; values on dem are interpreted as real heights (default).

--unitcell

horizontal and vertical scale is measured in number of cell lengths; values on dem are interpreted as number of cell lengths.

Operation¶

Calculates the planform curvature (i.e. the curvature transverse to the slope) on the elevation map dem. For each cell, the curvature is calculated in a 3 x 3 cell window, where the cell under consideration is in the center of the window.

The planform curvature on Result is the change in slope per distance in horizontal direction, in direction of the slope. It is negative at concave slopes and positive at convex slopes. The slope is dZ/dX, which is the increase in height (vertical direction dZ) per distance in horizontal direction (dX). The planform curvature is the change in slope per distance in horizontal direction, so it is dZ/dX 2. For a correct calculation of the planform curvature, the scale for the horizontal distance on dem and the vertical distance (height) on dem must be the same and the global option --unittrue must be set (it is default). In that case, the scales of Z and X correspond and the planform curvature on Result is in 1/dX.

The planform curvature is calculated according to the equation given by Zevenbergen.

Group¶

This operation belongs to the group of Derivatives of elevation maps

profcurv

Examples¶

1. • pcrcalc
binding
Result = Result.map;
Dem = Dem.map;
initial
report Result = roundoff(100*plancurv(Dem))/100;

• python
 Result.map Dem.map  