Inverse modeling has become a standard technique for estimating hydrogeologic
parameters. These parameters are usually inferred by minimizing the sum of the squared
differences between the observed system state and the one calculated by a mathematical
model. The robustness of the least squares criterion, however, has to be questioned
because of the tendency of outliers in the measurements to strongly influence the outcome
of the inversion. We have examined alternative approaches to the standard least squares …

Inverse modeling has become a standard technique for estimating hydrogeologic
parameters. These parameters are usually inferred by minimizing the sum of the squared
differences between the observed system state and the one calculated by a mathematical
model. The robustness of the least-squares criterion, however, has to be questioned
because of the tendency of outliers in the measurements to strongly influence the outcome
of the inversion. We have examined alternative approaches to the standard leastsquares …