Simulation Objects

Reservoir Objects

Flashboard and Superboard Spill methods

In the reservoir flashboards and superboards unregulated spill methods, a check was added to see if the availability slot is input or set by a rule. Previously, the availability was just checked for inputs, not rules. Now, users can set the availability with a rule.

Surcharge Error Check

An error check was added to the Flattop Surcharge method to ensure that the non-zero portion of the Rating Curves is increasing.

Peak Power Equation with Off Peak Spill - Warning message removed

In the Peak Power Equation with Off Peak Spill method on the power reservoirs, the following warning message was removed: “Pool Elevation too low to generate power.” This warning message was posted any time the reservoir was below the Minimum Power Elevation. The method behaves the same as previously: power and energy are still calculated to be zero; only the message has been removed.

Compute Incremental Hydrologic Inflows on Subbasin category

Two new methods were added to reservoir objects in the new Calculate Incremental Hydrologic Inflows on Subbasin category: Compute Full Run Incremental Hydrologic Inflows and Compute Forecast Period Incremental Hydrologic Inflows methods. These methods are used to disaggregate cumulative hydrologic inflows. The first method disaggregates cumulative inflows to Incremental Hydrologic Inflows for the entire run. The second method forecasts and disaggregates cumulative inflows to incremental hydrologic inflows on each timestep throughout the forecast period.

Slot name change: Deterministic Hydrologic Inflow

On reservoir objects, the name of the slot “Deterministic Hydrologic Inflow” was changed to “Cumulative Hydrologic Inflow.” In addition, the forecast methods in the Generate Forecast Hydrology category that previously used the “Deterministic Hydrologic Inflow” slots now use the new “Deterministic Incremental Hydrologic Inflow.”

If you use one of the Generate Forecast Hydrology methods that use these slots, there are two options:

• If you wish to continue using data in the old “Deterministic Hydrologic Inflow” slot in its previous form (either cumulative or incremental), it is recommended that you re-input the data into the new “Deterministic Incremental Hydrologic Inflow” slot. If you do not re-input the data, RiverWare will automatically copy the existing data from the new Cumulative Hydrologic Inflow into the Deterministic Incremental Local/Hydrologic Inflow at the beginning of a run. The data will not have input flags. To see or modify the input data, you would need to select the Compute Forecast Period Incremental Hydrologic Inflow method in the Calculate Incremental Hydrologic Inflows on Subbasin method temporarily. Because of this, it is recommended that you re-input the data into the Deterministic Incremental Hydrologic Inflow slot.

• If you have cumulative flows in the old Deterministic Hydrologic Inflow slot and you plan to disaggregate the flows using one of the new methods, the data should remain in the new Cumulative Hydrologic Inflow slot. You then must select a new disaggregation method in the Calculate Incremental Hydrologic Inflows on Subbasin category on the reservoir and create a subbasin to perform the disaggregation.

In addition, if any of these slots are referenced by DMIs, output manager devices, rules, or expression slots the models will need to be modified. See Generate Forecast Hydrology in Objects and Methods for information on the Generate Forecast Hydrology category for the storage reservoir.

Control Point

Variable Routing Coefficients category

A new category, Variable Routing Coefficients was added to the Control Point. Within this category, a new method, Compute Aggregate Coefficients allows the user to specify that this Control Point has an alternative set of routing coefficients that are to be used in the Flood Control calculation. See Control Point Variable Routing Coefficients category for more information.

Local Inflow Spatial Disaggregation on Subbasin category

This category has two methods that are used to hold the slots necessary for the calculation of Distributed Flow at an ungaged control point using the known flow at the Gage Control Point on the computational subbasin. In the WAM Precipitation Curve Number method, there are six slots: Distributed Flow, Drainage Area, Curve Number, Mean Precipitation, Upstream Gages, and Downstream Gage. These slots will be accessed by the computational subbasin when executing the computational subbasin’s WAM Precipitation Curve Number method. In the Drainage Area method, there are four slots: Distributed Flow, Drainage Area, Upstream Gages, and Downstream Gage. In both of these methods, the computational subbasin will use the user input Distributed Flow values in the Gage Control Point to calculate and set the Distributed Flow values at all other control points in the subbasin. The WAM Precipitation Curve Number method takes into account the drainage area, mean precipitation and NRCS Curve Number while the Drainage Area method uses only the drainage area in the calculation. For more information, see Local Inflow Spatial Disaggregation on Subbasin in Objects and Methods.

Gage Control Point category

A new category, Gage Control Point, was added to the Control Point when the WAM Precipitation and Curve Number method is selected. Methods in this category are used to indicate which Control Points are the “gage” control points. There are two methods in this category: the default, no action None method and the Gage Control Point method. When selected, the Gage Control Point method indicates that the control point is considered a “gage” control point. When this method is selected, the Control Point changes from a blue color to an orange color. For more information, see Gage Control Point in Objects and Methods.

Local Inflow Temporal Disaggregation on Subbasin category

A new method category, Local Inflow Temporal Disaggregation on Subbasin, was added to the control point. The Local Inflow Temporal Disaggregation on Subbasin method category contains two new methods: None, and Specified Factors. The Specified Factors method contains one new slot: Temporally Disaggregated Flow. This slot holds the result of the temporal disaggregation as calculated from the computational subbasin. For more information, see Local Inflow Temporal Disaggregation on Subbasin in Objects and Methods.

Compute Incremental Local Inflows on Subbasin category

Two new methods were added to control point objects in the new Calculate Incremental Local Inflows on Subbasin category: Compute Full Run Incremental Local Inflows and Compute Forecast Period Incremental Local Inflows methods. These methods are used to disaggregate cumulative local inflows. The first method computes incremental local inflows for the entire run. The second method computes forecasted incremental local inflows on each timestep for the forecast period. For more information, see Compute Incremental Local Inflows on Subbasin in Objects and Methods.

Slot name change: Deterministic Local Inflow

On Control Points, the name of the slot “Deterministic Local Inflow” was changed to “Cumulative Local Inflow.” In addition, the forecast methods in the Generate Forecast Inflows category that previously used the “Deterministic Local Inflow” slots now use the new “Deterministic Incremental Local Inflow.”

If you use one of the Generate Forecast Inflows methods that use these slots, there are two options:

• If you wish to continue using data in the old “Deterministic Local Inflow” slot in its previous form (either cumulative or incremental), it is recommended that you re-input the data into the new “Deterministic Incremental Local Inflow” slot. If you do not re-input the data, RiverWare will automatically copy the existing data from the Cumulative Local Inflow into the Deterministic Incremental Local Inflow at the beginning of a run. The data will not have input flags. To see or modify the input data, you would need to select the Compute Forecast Period Incremental Local Inflow method in the Calculate Incremental Local Inflows on Subbasin method temporarily. Because of this, it is recommended that you re-input the data into the Deterministic Incremental Local Inflow slot.

• If you have cumulative flows in the old Deterministic Local Inflow slot and you plan to disaggregate the flows using one of the new methods, the data should remain in the new Cumulative Local Inflow slot. You then must select a new disaggregation method in the Calculate Incremental Local Inflows on Subbasin category on the Control Point/reservoir and create a subbasin to perform the disaggregation.

In addition, if any of these slots are referenced by DMIs, output manager devices, rules, or expression slots the models will need to be modified. See Generate Forecast Inflows in Objects and Methods for details on the Generate Forecast Inflows category for the Control Point.

Computational Subbasin

Control Point Variable Routing Coefficients category

Functionality was added to allow the subbasin to use alternative routing coefficients in the Flood Control calculation. A new category called Control Point Variable Routing Coefficients was added to the computational subbasin. In this category are two methods, a default do-nothing No Method, and the new method Compute Aggregate Coefficients. This new Compute Aggregate Coefficients method is used to determine the set of routing coefficients to use for each Control Point in the subbasin. For each Control Point, the method aggregates routing coefficients using the intervening reach routing methods. This allows the Flood Control calculation to make use of variable routing coefficients during high flow events. This calculation is only performed during the Flood Control calculation and does not affect the routing in the simulation objects. For more information, see Control Point Variable Routing Coefficients in Objects and Methods.

Multiple downstream-most objects in flood basin

It is now possible to have more than one downstream-most object in a subbasin used by the Flood Control predefined function.

Local Inflow Spatial Disaggregation

A new method category, Local Inflow Spatial Disaggregation, was added to the computational subbasin. The category contains three methods: the default no-action method None, the WAM Precipitation Curve Number, and the Drainage Area method. The WAM Precipitation Curve Number method calculates the Distributed Flow at an ungaged control point using the known flow at the Gage Control Point as well as the NRCS curve number, mean precipitation, and drainage area of both the gaged and ungaged control points. The Drainage Area method calculates the Distributed Flow at an ungaged control point using known flow at the Gage Control Point using drainage area ratios only. For more information, see Local Inflow Spatial Disaggregation in Objects and Methods.

Local Inflow Temporal Disaggregation

A new method category, Local Inflow Temporal Disaggregation, was added to the computational subbasin. The category contains two methods: the default no-action method None, and the Specified Factors method. The Temp Disagg Factors slot is required input for the Specified Factors method and holds a daily timeseries of the factors by which the monthly Distributed Flow values are multiplied to temporally disaggregate to daily. In practice, the data for the Temp Disagg Factors slot can be developed from historical daily data that is converted to a daily factor (percent per day of the monthly value). This slot is located on the computational subbasin (and not the control point) because the disaggregation factors apply to all control points in the subbasin. For more information, see Local Inflow Temporal Disaggregation in Objects and Methods.

Compute Incremental Local Inflows

A new method category, Calculate Incremental Local Inflows, was added to the computational subbasin. The category contains three methods: the default no-action method None, the Compute Full Run Incremental Local Inflows method, and the Compute Forecast Period Incremental Local Inflows method. The latter two methods calculate the incremental local inflows to all control points and reservoirs in the subbasin given the cumulative local inflows at each object without forecasting and with forecasting, respectively. The computational subbasin(s) must be set up by the user and must include all control points and reservoirs which contain the cumulative local inflow data as well as all the intervening reaches and confluences. Cumulative local inflow data can be either cumulative until a reservoir is reached in the river system or continue through one or more reservoirs. For more information, see Incremental Local Inflows in Objects and Methods.

Reservoir Boundary for Incrementals Category

A new category Reservoir Boundary for Incrementals is available if one of the Calculate Incremental Local Inflows is selected. The category contains three methods, the default Stop at Reservoirs, Continue Through Reservoirs, and Ignore Reservoirs. These methods are used to specify how cumulative local inflows are configured in the basin. For more information, see Reservoir Boundary for Incrementals in Objects and Methods.

Diversion Object

Change to SolveMB_GivenOutflow dispatch method

On the Diversion object's solveMB_givenOutflow dispatch method, “Available for Diversion” was removed as a required known in the dispatch conditions. This dispatch method solves for the Diversion and Diversion Request given the Multi Outflow. Typically, the Multi Outflow is calculated by a rule using the ComputeReservoirDiversions predefined function. This function determines the reservoir diversion and limits diversions to be less than the available water in the reservoir. As a result, Available for Diversion is not a required known for this dispatch method. For more information, see Solve given Multi Outflow in Objects and Methods.

Reach

Base Plus Fractional Loss Method in the GainLoss Calculation Category

A new method Base Plus Fractional Loss was added to the GainLoss Calculation category on the reach. This method models loss in a reach as a base loss plus a loss fraction of the flow above that base. In addition, total loss is limited to a maximum value. For more information, see Base Plus Fractional Loss in Objects and Methods.

Variable Step Response routing method

A new routing method, Variable Step Response, was added to the Reach. In this routing method, the user specifies a set of flow thresholds and a set of corresponding step response routing coefficients. When the reach dispatches, the routing method selects the appropriate routing coefficients based on the inflow to the reach. This method was added to support systems where large overbank floods lead to increased travel times. For more information, see Variable Step Response in Objects and Methods.

Water User

Fraction Return Flow Input category

A new category called Fraction Return Flow Input was added to the Water User object. This category, dependent on the selection of the Fraction Return Flow method in the returnFlowCalculation category, specifies how the Fractional Return Flow slot is to be input. Within this category are three new methods: Input Fraction, Zero Fraction, and Periodic Fraction. The default method is the Input Fraction which duplicates the existing functionality. The Zero Fraction method sets a zero for Fraction Return Flow each timestep. The Periodic Fraction allows the user to input a periodic slot that is used to calculate the Fractional Return Flow. For more information, see Fraction Return Flow Input in Objects and Methods.

Revised: 08/02/2021