The Farm Wells in FMP: Farm Process pane is on the MODFLOW Features tab of the Object Properties dialog box.
The Farm Wells in FMP: Farm Process pane is used to define wells associated with particular farms that can be used by the farm to provide supplemental water when needed. For each well, the user must specify the maximum capacity of the well (the maximum pumping rate that the well can provide), the Farm ID of the farm with which the well is associated, and whether or not it should be pumped only if there is an irrigation requirement in the cell containing the well. The latter must evaluate to either True or False. Farm wells are not be required to be in the farm with which they are associated.
In MODFLOW, the Pumping Rate or Maximum Capacity is described as having units of L3/T.
However, sometimes it is convenient to define a well using a line or polygon object.
For Polyline Objects, the length of the object in the cell can be determined with the function ObjectSectionIntersectLength.
One way to to set the pumping rate would be with a formula that includes ObjectSectionIntersectLength and either a value or a user defined Global Variables for the pumping rate per unit length. For example, the user could define a Global Variables named "RatePerLength" and then set the pumping rate of the well using the following formula.
RatePerLength * ObjectSectionIntersectLength
A similar formula appropriate for Polygon Objects would be
RatePerArea * ObjectIntersectArea
where "RatePerArea" is a global variable.
However, if Pumping Rate Interpretation is set to Calculated, as it is by default, ObjectSectionIntersectLength and ObjectIntersectArea should not be included in the formulas because they will be incorporated automatically for polyline and polygon objects. Thus, if Pumping Rate Interpretation is set to Calculated for a Polyline Object, the pumping rate should be treated as if its units were L2/T.
Pumping Rate Interpretation has no effect for point objects. For point objects, the formulas will be applied without any modification regardless of Pumping Rate Interpretation.
if Pumping Rate Interpretation is set to Calculated for a Polygon Object, the pumping rate should be treated as if as if its units were L/T.
If Pumping Rate Interpretation is set to Direct, the formulas will be applied without any modification.
If Pumping Rate Interpretation is set to Total per layer the formulas will be modified by multiplying the conductance by ObjectSectionIntersectLength / ObjectLength or ObjectIntersectArea / ObjectArea.
Setting the Pumping Rate Interpretation to Calculated or Total per layer allows ModelMuse to calculate an appropriate pumping rate for a cell based on the length or area of intersection between the object and cell. However, if you calibrate your model and then change the grid size, the pumping rate assigned by ModelMuse may no longer be appropriate and you may have to recalibrate your model.
