Geomorphometry Terms
Geomorphometric Parameters
Parameter | Formula | Interpretation of Values | Reference |
Flatness | Ln(S_{1}/S_{2}) | Large values indicate flat terrain, low values rugged terrain. Correlates strongly and negatively with slope or relief. | Guth papers listed in Terrain organization |
Organization | Ln(S_{2}/S_{3}) | Large values indicate a dominant linear fabric to the terrain, low values isotropic topography | Guth papers listed in Terrain organization |
Orientation | Trend of S_{3} | Dominant trend to the terrain fabric, direction between 0 and 180°. Used in eigenvector analysis of SSO diagrams. | Guth papers listed in Terrain organization |
Strength, c | Ln(S_{1}/S_{3}) | Large values indicate flat terrain, low values rugged terrain. Very similar to the flatness parameter. Correlates strongly and negatively with slope or relief. Used in eigenvector analysis of SSO diagrams. | Fisher, Lewis, and Embleton, p.159 |
Shape, k | Ln(S_{1}/S_{2})/Ln(S_{2}/S_{3}) | Large values indicate a dominant linear fabric to the terrain, low values isotropic topography. Correlates moderately with organization. | Fisher, Lewis, and Embleton, p.159 |
Ghost ratio | (Percentage points on contour lines) / (Percentage elevations that are contour lines) | Indicates the overrepresentation of contour line elevations in the DEM, an artifact of the digitizing process if the ghost ratio exceeds 1. The ghost ratio is never significantly less than 1. | Guth, 1999 |
S_{1}, S_{2}, and S_{3} are the eigenvalues from the 3x3 matrix of the sums of the cross products of the direction cosines for all points in the analysis region.
S_{1}> S_{2}> S_{3}.
Last modified 5/24/2006