pij = perimeter (m) of patch ij.
aij = area (m2) of patch ij.
Description SHAPE equals patch perimeter (m) divided by the square root of patch area (m2), adjusted by a constant to adjust for a square standard.
Units Units
Range SHAPE ≦ 1, without limit.
SHAPE = 1 when the patch is square and increases without limit as patch shape becomes more irregular.
Comments Shape index corrects for the size problem of the perimeter-area ratio index (see previous description) by adjusting for a square standard and, as a result, is the simplest and perhaps most straightforward measure of shape complexity.