Data View, Branch: Catchments,
Category: Climate, Tab: Precipitation, ETreference. This screen is used in conjunction with the MABIA Method for catchment hydrology and crop water requirements. It is accessible via the drop-down menu on the data grid for the "Irrigation Schedule" variable under Irrigation.
A description of the irrigation methods can be found in the description of the IrrigationSchedule function. Once you have entered the appropriate data into the Irrigation Scheduling Wizard, click the Save button and WEAP will create the corresponding IrrigationSchedule expression that embodies this data. The following will describe how to enter this data into the wizard.
At the top of the wizard, select the number of irrigation schedules per year (for all crops combined). For example, if you had corn followed by winter wheat, and each had 1 irrigation schedule, you would enter 2. If the irrigation schedule expression was initially blank, when the Irrigation Scheduling Wizard starts WEAP will automatically add all crops defined for this branch, and set the default irrigation schedule for each: triggered at 100% of RAW, with an application of 100 % of Depletion. This will ensure that soil moisture depletion never goes below RAW so that no crop water stress will occur. Of course, you can make changes to these defaults.
Each row of the table defines one irrigation schedule, with the following columns of information:
Choose the crop for the irrigation schedule. Only the crops already chosen for this branch are available here for selection.
The season length from the Crop Library for this crop (the sum of all four crop stages) will be displayed for information.
Enter the number of the day on which this irrigation schedule takes effect, counting from the first day of the crop season. To start on the first day, enter 1.
Enter the number of the day on which this irrigation schedule ends, counting from the first day of the crop season. To end on the last day, enter the crop season length.
The dates corresponding to the start and end days will be shown for information.
Select one of the four irrigation trigger methods, as described in the IrrigationSchedule function: Fixed Interval, % of RAW, % of TAW, Fixed Depletion. This will determine on which days irrigation will occur.
Enter the value that goes with the IrrigationTriggerMethod: days (fixed interval), % (% of RAW or % of TAW), mm (fixed depletion).
Select one of the four irrigation amount methods, as described in the IrrigationSchedule function: % of Depletion, % of RAW, % of TAW, Fixed Depth. This will determine how much irrigation water to apply.
Enter the value that goes with the IrrigationAmountMethod: % (% Depletion, % of RAW or % of TAW), mm (fixed depth).
Note: If there are gaps in the irrigation dates between schedules, there will be no irrigation during those periods. There is no irrigation in the fallow periods (before or after the crop season).
See also: MABIA Calculation Algorithms
Entered on: Data View, Branch: Catchments,
Category: Climate, Tab: Precipitation, ETreference.