Irrigation

(These parameters apply to the Soil Moisture method. For the FAO Method, see FAO Method, Irrigation; for the MABIA Method, see MABIA, Irrigation.)

If you indicate that irrigation is to occur in a Catchment at the time you create the Catchment in the Schematic, the Irrigation tab will appear under the particular Catchment in the Data View. The following irrigation-related variables will require input if the Soil Moisture method is chosen for the Catchment.

Irrigated Area

The percent of area that is irrigated.

Lower Threshold

Irrigate when soil moisture falls below this percent level.

Upper Threshold

Cease irrigation when soil moisture reaches this percent level.

Pump Layer

Groundwater layer or layers (as defined in linked MODFLOW model) from which to pump for irrigation. Specify layer=255 for a cell to have pumping come equally from all layers in that cell. To have withdrawals handled instead as negative recharge, specify layer=0. If pump layer>0, WEAP will add cells to the well file if they are not already there. Use the PumpLayer function to specify fractions to pump from several layers. If blank, will default to 0 (negative recharge).

Depending on the setting in General: Basic Parameters, the pump layer can either be entered once for each catchment and will apply to all the land use branches within that catchment, or can be entered separately for each branch within each catchment.

Note: Pump Layer is only used when linked to MODFLOW.

See also: Soil Moisture Method Calculation Algorithm

Entered on: Data View, Branch: Catchments, Category: Irrigation, Tabs: Irrigated Area, Lower Threshold, Upper Threshold, Pump Layer.