Table 9.

Estimates of the Van Genuchten model parameters, $k_u$, and calibration parameters using the PF method with ${\sigma }_{obs}$ values of 0.01, 0.02 and 0.03 for the application case with field data.

Parameter	${\mathit{\sigma }}_{\mathit{obs}}$	${\mathit{\theta }}_{\mathit{r}}$	$\mathit{\alpha }$	n	${\mathit{k}}_{\mathit{s}}$	${\mathit{k}}_{\mathit{u}}$	a	b
Initial value		0.067	0.02	1.41	0.005	0.005	1	0
Estimates	0.01	0.0741	0.01858	1.4839	0.0020	0.0053	0.5072	0.0623
	0.02	0.0562	0.0192	1.3253	0.0185	0.0052	0.7940	−0.0278
	0.03	0.0672	0.0196	1.4228	0.0040	0.0048	0.9710	−0.1110