Digital Soil Mapping in the Absence of Field Training Data: A Case Study Using Terrain Attributes and Semiautomated Soil Signature Derivation to Distinguish Ecological Potential

Table 2

Correlation matrix for ten topographic indices derived from 5 m IFSAR digital terrain model. Variables were transformed to range between zero and one. Values are summarized from 36 pixels that occurred within a 30𝑚×30𝑚 Landsat image pixel.

	Mean plan†	SD plan	Max plan	Mean pro	SD pro	Max pro	Mean slope	Mean TWI	SD TWI	Max TWI
Mean plan	1.000	−0.017	0.630	−0.431	−0.034	−0.313	0.028	−0.491	0.003	−0.430
SD plan		1.000	0.611	0.047	0.250	0.229	0.114	−0.052	0.183	0.099
Max plan			1.000	−0.261	0.152	−0.052	0.069	−0.387	0.105	−0.245
Mean pro				1.000	−0.016	0.588	0.047	0.397	0.093	0.376
SD pro					1.000	0.660	−0.135	−0.130	0.146	0.067
Max pro						1.000	−0.090	0.135	0.151	0.289
Mean slope							1.000	0.324	−0.427	−0.212
Mean TWI								1.000	−0.135	0.555
SD TWI									1.000	0.570
Max TWI										1.000

†plan: planar curvature; SD: standard deviation; pro: profile curvature; max: maximum; TWI: topographic wetness index.