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Objects and Methods : Reservoir Methods : User Methods : Evap and Precip Rate Specification
Evap and Precip Rate Specification
This category allows you to choose how the evaporation and precipitation rates will be specified. The category is only available when the Input Evaporation method in the Evaporation and Precipitation category is specified.
* None
This is the default method; that is, the rates must be input, set by a rule, or they default to 0.0.
* Monthly Rates
This method allows you to specify the evaporation and precipitation rates as a series of monthly values for the entire run.
Slots Specific to This Method
 Evaporation Rate Monthly
Type: Series Slot
Units: Velocity
Description: The evaporation rate for each month of the run.
Information: You must set the timestep for this series slot to be 1 Month. Because this slot’s timestep is 1 Month, it is most likely different than the run timestep. As a result, if you “synchronize objects”, you must select the toggle in the synchronization control to “Exclude Slots with Different Timestep from Run.” This will prevent changing the timestep of this slot when other slots are synchronized.
I/O: Optional input
 Precipitation Rate Monthly
Type: Series Slot
Units: Velocity
Description: The precipitation rate for each month of the run.
Information: You must set the timestep for this series slot to be 1 Month. Because this slot’s timestep is 1 Month, it is most likely different than the run timestep. As a result, if you “synchronize objects”, you must select the toggle in the synchronization control to “Exclude Slots with Different Timestep from Run.” This will prevent changing the timestep of this slot when other slots are synchronized.
I/O: Optional input
Method Details 
At the beginning of run, the method disaggregates the Evaporation Rate Monthly and Precipitation Rate Monthly to the Evaporation Rate and Precipitation Rate slots, respectively. If the timestep of the run is 1 Month, it uses the values directly. If the timestep of the run is less than a month, it look ups the month that contains the given timestep and uses that value. No interpolation is performed.
If the run timestep is 1 Year, an error is issued.
If the two slots do not have a timestep of 1 Month but have inputs, an error is issued.
If there is no value in the monthly slot for a given month, then the rate is set to 0.0.
* Periodic Rates
This method allows you to specify the evaporation and precipitation rates as a periodic relationship.
Slots Specific to This Method
 Evaporation Rate Periodic
Type: Periodic Slot
Units: Velocity
Description: The evaporation rate as a periodic relationship.
Information: Like other periodic slots, you can choose the period and whether to interpolate or lookup.
I/O: Required input
 Precipitation Rate Periodic
Type: Periodic Slot
Units: Velocity
Description: The precipitation rate as a periodic relationship.
Information: Like other periodic slots, you can choose the period and whether to interpolate or lookup. If you do not wish to model precipitation, you still must enter a zero in this periodic slot.
I/O: Required input
Method Details 
At the beginning of run, the method sets the Evaporation Rate and Precipitation Rate slots by looking up (or interpolating as configured on the periodic slot) the given timestep in the Evaporation Rate Periodic and Precipitation Rate Periodic slots, respectively. If accessing the periodic slot fails due to missing values, then an error is issued and the run stops.
Revised: 01/05/2024