Table 5.

Best-fitted semivariogram models of heavy metals and their parameters

Soil attributes	Model	C 0	C + C 0	C 0/C + C 0	Range (km)	R 2
As	Exponential	0.536	0.976	0.55	58.86	0.78
Cd	Spherical	0.666	1.316	0.51	48.90	0.87
Co	Exponential	5.938	12.845	0.46	38.01	0.72
Cr	Exponential	0.039	0.077	0.51	60.84	0.86
Cu	Circular	0.054	0.088	0.61	44.19	0.75
Ni	Circular	0.055	0.141	0.39	86.12	0.95
Pb	Spherical	0.48	0.994	0.48	21.22	0.68
V	Circular	0.016	0.08	0.20	20.74	0.64
Zn	Rational quadratic	0.026	0.058	0.45	54.38	0.76
Fe	Exponential	0.011	0.048	0.23	32.47	0.70

C ₀ nugget variance, C structural variance, C + C ₀ sill variance