Stage Adjustment
This category is only available when the Inflow Stage Table Look Up or Stage Table Lookup method is selected from the Stage category.
None
This method is the default for this category. It performs no calculations.
There are no slots specific to this method.
Stage Coefficient Weighting
This method adjusts the current stage to be a weighted sum of the previously computed current stage and previous timesteps’ stage values.
Slots Specific to This Method
Stage Weighting Coefficients
Type: Table
Units: None
Description: Coefficients used to weight previous temporary stage.
Information: The values in the table should sum to 1.0.
I/O: Required input
Links: N/A
Method Details
Stage Weighting Coefficients are defined in this table slot, which contains a number of user-defined coefficients corresponding to the number of timesteps you want to include in the weighted sum. Previously computed Stage values are looked up for the current timestep and a number of previous timesteps, corresponding to the number of coefficients in the aforementioned table. Then, the adjusted Stage is computed as follows:
where the C0, C1,..., Cn are the Stage Weighting Coefficients.
If the Inflow Stage Table Look Up method is selected from Stage category, the tempStage(t) is the InflowStage(t).
If the Stage Table Look Up method is selected from Stage category, the tempStage(t) is the computed stage, which is typically the average of the InflowStage(t) and OutflowStage(t).
This method requires previous timestep values. At the start of the run (start to start+n), if these values are not available, the method will use only current timestep tempStage and assume coeffs are {1,...}. At timesteps after (start+n), if the previous values are invalid, a message will be posted and stop the run.
The default convergence on stage may be too loose for this method to work, depending on the magnitudes of stage values. The convergence percentage may have to be tightened from the default 0.01% to an order of magnitude less, 0.001%, or to an even more precise convergence percentage. Convergence is adjusted in the
Configure menu; see
“Configure Slot Dialog Functionality” in User Interface for details.