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Reach - Solve Outflow method with Lagged Inflows
On a Reach using the No Local Inflow, Solve Outflow method (in the Local Inflow and Solution Direction category), it was possible to specify or propagate an Outflow that was inconsistent with the lagged Inflow. Now, this circumstance will result in an error.
Dispatch Slots
The Reservoir slots Evaporation Rate and Precipitation Rate were added to the list of dispatch slots. Now they are linkable and a new value (input, propagated, set by a rule) will trigger the object to redispatch, if possible.
Max Outflow Calculation on the Slope Power Reservoir
The max outflow computation iterates to find the Storage in the Slope Power Reservoir. This calculation uses the current outflow as one of the parameters in the computation (in Impulse Response slope storage calculation especially). Previously, it used the values on the Outflow slot which came from a previous dispatch. Once the max computation is complete, it sets the Outflow slot. Within the rest of the dispatch, it then uses that Outflow as the current value in the slope storage calculation. Since this is different, the Storage, Pool Elevation, and headwater are all different, thus leading to a different max Turbine Release and Spill.
The code was changed to use the values that are computed within the iteration for the current Outflow. In a test model, this does slightly change results. For example, in one test model, the flow on one timestep went from 293.50 (1000cfs) to 293.52 (1000cfs). The pool then changed by 0.0001ft. On the final timestep, the pool was 0.001ft different. They are not significantly different, but these can compound over time as the storage changes.
Reservoir Accounting Methods
The following two Table Series Slot columns were duplicated on separate Series Slots:
• Est Sed Deposition - Accumulated Perm Sediment column was duplicated on the Accumulated Permanent Sediment slot. This slot is added by the Total Vol Sed (Post2000) method in the Sediment Transport Calculations category.
• Rio Grande Pools - Carryover Content column was duplicated on the Carryover Content slot. This slot is added by the Abiquiu Gain Loss, Jemez Gain Loss or the Cochiti Gain Loss methods in the Reservoir Account Gain Loss category.
These series of data are duplicated on the individual series slots. The series slots hold the values used in the calculation but the data is also shown in the original table series slot. (This allows any existing output devices to continue working without changes.) In addition, if the value on series slot is not known, but the value on the table series slot is known, the table series slot value is copied to the series slot at the initial timestep and set as an input. This will preserve it for future runs and when aggregating to monthly.
In addition, previously on the Present Condition Table Series Slot, the River Channel Area and Barren Area values were required inputs on the initial timestep for a monthly run. These are now computed from other data. This slot is part of the Abiquiu Gain Loss, Jemez Gain Loss or the Cochiti Gain Loss, El Vado Gain Loss, Nambe Falls Gain Loss, and Elephant Butte Gain Loss (both variations) methods in the Reservoir Account Gain Loss category.
Reach and Reservoir - Coeff and Exponent and Forecast methods
Within the Coefficient and Exponent method on the reach (Generate Local Inflows category) and reservoirs (Generated Forecast Hydrology category), a minimum deterministic inflow was implemented. Now the Lower Bound on the Deterministic Local/Hydrologic Inflow slot is used as a minimum value in the computation. Any absolute values smaller than the minimum values behave as though the value is zero; that is, the deterministic value is used directly in place of a forecast value. For more information, see Coefficient and Exponent in Objects and Methods on the reach and Coefficient and Exponent in Objects and Methods on the storage reservoir.
Water User
Soil Moisture Modifications
The Water User soil moisture return flow methods Proportional Shortage with Soil Moisture and Variable Efficiency with Soil Moisture were modified with a new slot, Surface Runoff. In addition, the Supplement Diversion including Soil Moisture method in the Conjunctive Use category was modified to have an additional slot, Supplemental Runoff.
These slots represent water that is applied that is higher than max infiltration rate and runs off directly. If these slots are linked, the corresponding Return Flow does NOT include that water as it goes elsewhere. If they are not linked, the Return Flow does include that water and these two slots are for informational purposes. This distinction is needed as the quality of this water is different than the water that moves through the soil. For more information on new water quality salinity methods on the water user, see Water User.
Water User Performance Improvement
The run time performance of the Water User's SW GW Impulse Response return flow routing method was improved. In one test model, the run time was reduced by 27%.
Revised: 08/02/2021