When performing automated parameter estimation, a set of head and flux observations are defined using points, arcs, and polygons in the map module. Each of these observations has a weight assigned to it when it is imported to the inverse model. In addition to the individual weight, a group weight can also be assigned. Group weights are assigned using the Group Weight section of the Observations dialog. This dialog is accessed by selecting the Observations command in the MODFLOW menu.
A group weight can be assigned to each of the following observation types:
Head observations.
Constant head flow observations.
River flow observations.
General head flow observations.
Drain flow observations.
Stream flow observations.
Options 2-6 correspond to flow observations that are defined using the Observed flow rate option.
The default value for the group weights is 1.0. The default value can be changed to give a larger influence to a particular observation type. For example, if a particular model had sixteen head observations and one flux observation corresponding to a stream gage, a better solution may be obtained by increasing the flux group weight to give more weight to the stream gage measurement.
Related Links:
Automated Parameter Estimation