Soil-Landscape Modeling and Remote Sensing to Provide Spatial Representation of Soil Attributes for an Ethiopian Watershed

Table 5

Regression models to predict clay percent of the surface layer using terrain attributes only (without satellite images).

Class No.	Constant	Slope (%)	As	CTI	Aspect	Curvature	𝑅^2
1	15.06	0.06	0.00001	0.23	0.27	0.61	0.10
2	46.18	−0.53^∗∗	0.0001^∗	−1.29	0.88	1.07	0.37
3	19.31	−0.28^∗	0.00006	0.29	4.54^∗∗	−4.55^∗∗	0.68
4	3.44	−1.38^∗	−0.00008	2.68	3.17	2.37	0.46
5	0.97	−0.11	−0.0002	1.78	1.25	1.10	0.18
6	66.35	−0.40^∗∗	0.0002^∗∗	−2.30	−2.11^∗	−1.41	0.45
7	3.46	−0.22^∗	−0.00004	1.85	1.25	2.52	0.24

∗Significant at the 0.05 probability level; **significant at the 0.01 probability level.
As: upslope contributing area; CTI: compound topographic index.