Tool Name	Morphometric Features
Tool ID	23
Library ID	ta_morphometry
Version	1.0
Author(s)	O.Conrad (c) 2013

Description

The tool uses a multi-scale approach by fitting quadratic parameters to any size window (via least squares) to derive morphometric terrain parameters like slope, aspect and curvatures. These can be used for subsequent classification of morphometric features (peaks, ridges, passes, channels, pits and planes). This is the method as proposed and implemented by Jo Wood (1996) in LandSerf and GRASS GIS (r.param.scale).

The following datasets can be computed:
- Morphometric features is the terrain classification.
- Generalised elevation is the smoothed input DEM.
- Slope is the magnitude of maximum gradient. It is given for steepest slope angle and measured in degrees.
- Aspect is the direction of maximum gradient.
- Profile curvature is the curvature intersecting with the plane defined by the Z axis and maximum gradient direction. Positive values describe convex profile curvature, negative values concave profile.
- Plan curvature is the horizontal curvature, intersecting with the XY plane.
- Longitudinal curvature is the profile curvature intersecting with the plane defined by the surface normal and maximum gradient direction.
- Cross-sectional curvature is the tangential curvature intersecting with the plane defined by the surface normal and a tangent to the contour - perpendicular to maximum gradient direction.
- Minimum curvature is measured in direction perpendicular to the direction of of maximum curvature.
- The maximum curvature is measured in any direction.

Parameters

Name	Type	Identifier	Description	Constraints
Input
Elevation	grid, input	DEM
Output
Morphometric Features	grid, output, optional	FEATURES
Generalized Surface	grid, output, optional	ELEVATION
Slope	grid, output, optional	SLOPE
Aspect	grid, output, optional	ASPECT
Profile Curvature	grid, output, optional	PROFC
Plan Curvature	grid, output, optional	PLANC
Longitudinal Curvature	grid, output, optional	LONGC
Cross-Sectional Curvature	grid, output, optional	CROSC
Maximum Curvature	grid, output, optional	MAXIC
Minimum Curvature	grid, output, optional	MINIC
Options
Scale Radius (Cells)	integer number	SIZE	Size of processing window (= 1 + 2 * radius) given as number of cells	Minimum: 1 Default: 5
Slope Tolerance	floating point number	TOL_SLOPE	Slope tolerance that defines a 'flat' surface (degrees)	Default: 1.000000
Curvature Tolerance	floating point number	TOL_CURVE	Curvature tolerance that defines 'planar' surface	Default: 0.000100
Distance Weighting Exponent	floating point number	EXPONENT	Exponent for distance weighting (0.0-4.0)	Minimum: 0.000000 Maximum: 4.000000 Default: 0.000000
Vertical Scaling	floating point number	ZSCALE	Vertical scaling factor	Default: 1.000000
Constrain	boolean	CONSTRAIN	Constrain model through central window cell	Default: 0