This section presents a description of the different types of slots and how they are used for representing different types of data. Select a link for full details on how to view, create, and edit that type of slot.

There are several types of time series slots with various column configurations. Since all of these slot types contain rows that correspond to the series of data, they will be referred to collectively as series slots. Most series slots open automatically in a Slot Viewer. Any slot shown in the viewer can be detached from the viewer and shown in its own Slot windows by dragging the column off the viewer.

Figure 4.7 highlights the differences between the individual Slot window and the Slot Viewer.

The Slot Viewer is an ad hoc tool to view multiple series slots in a single window. There is one Slot Viewer per timestep size in a RiverWare session. The slots shown and order is not persistent in any way on the viewer. Each time a Series Slot is opened from anywhere in RiverWare, it is added as a column to the Slot Viewer. From the Slot Viewer, any slot can be shown also in the slot's conventional Slot window.

Figure 4.8 shows the Slot Viewer showing four slots on BigRes. The annotations correspond to the following numbers:

The Slot Viewer shows different menu options based on the selected slot. Highlight cells in a single column (or the entire column) to select a slot. If you highlight cells in multiple columns, the Selected Slot is blank and many of the menu options are disabled. For certain types of slots, like expression slots and Series Slots with Periodic Input, not all of the menu options are shown on the slot viewer. Undock the slot and use the Slot window to access all of the configuration and menu options.

Following are the Slot Viewer specific actions:

To dock a slot onto a Slot Viewer, drag the slot’s icon anywhere on the viewer. Figure 4.9 shows the icon that you should drag and the result. Alternatively, use the File, then Dock in Slot Viewer menu.

The two following types of slots have additional configuration options in the Slot Dialogs and have an additional icon/button in the column heading. Click this icon to open the slot in its own window and edit the periodic values.

Figure 4.10 shows the key areas of a series slot. There is a datetime selector and scroll button used to scroll to the given date. Icons and buttons are used to show display compression, show notes, and to Plot the slot. The datetimes are shown as the row headings, the data values are shown in the cells, and each cell’s value has a flag. Bold, green separators are automatically created based on the timestep of the slot. For example, in a slot with a 1 Day timestep, separators are placed between months. In 6 Hour slot, days are separated. Also, there is a blue divider between the initial and start timestep. There is a red divider after the finish timestep.

The units for both the default and alternative units are defined by the unit scheme. The unit type will apply unless an exception has been created for the slot. Exceptions can be created for both flows and volume unit types for a particular slot.

See Synchronize Series Slot Scrolling for more information on the model load setting that controls the setting on model load.

The Configure Slot window, shown in Figure 4.13, is displayed by selecting View, then Configure. Following are configuration options specific to Series Slots. See Configure Slot Dialog for details on general configuration.

As described in Alt Units button, flows slots can always be shown as the volume over the timestep. But only certain simulation slots, with the volume unit, can be shown as flows, like evaporation volume. For custom slots that you create, you can choose for each volume slot whether the Alt Units will apply. When the Unit Type is Volume, the Displayable as flow checkbox is shown as noted in Figure 4.14. Check the box indicating this volume can be shown as a flow, using the Alt Units button. Leave it unchecked if the volume is not displayable as a flow.

Series slots have upper and lower bounds as shown in Figure 4.15. In general, these values are not used by the simulation but are used in optimization. However, there are a few cases where a value can be used by the Object’s user methods. For example, the lower bound on Outflow on a Reach object is used to calculate the maximum allowable diversion. If no value is specified, the total Inflow may be diverted.

Optionally, you can show warning messages if values set during Simulation are out of bounds. When warning messages are configured, if the controller sets a value that violates the specified bounds, a warning is issued in the diagnostics window, but the simulation continues. See Warn when Values are out of Bounds.

Series slots have convergence settings that can be edited in the lower portion of the Configure Slot window as shown in Figure 4.15. A slot can be reset if the new value is not within convergence of the old value and it has not been set more than the maximum number of times. See Set Value in Solution Approaches for details.

Following are the available convergence criteria.

The default start times and timestep are inherited from the Run Control settings when the object is created or the slot is added. All series slots are initialized with one timestep to minimize model file size. Other rows are added as needed for input or appended at run time when the slot’s output values are calculated. You may change the time series range directly through the View and then Configure Timeseries window as shown in the screenshot for the reservoir Outflow simulation slot:

The time series range and timesteps can also be changed by selecting Align With Run Control. This will update the time series range in the slot to match the time series range set in the Run Control.

Custom series slots have an additional option to control whether synchronization is allowed:

The two choices are as follows:

In the View menu, there is a menu to show Linked Slots. When selected, this shows all of the slots to which the given slot is linked.

The Show Notes Column and the Notes Group menu are used to display Notes that are associated with a timestep on a series slot. See Notes on Series Slots for details.

The Series Display Compression utility allows the user to compress or hide a particular value, NaNs, both, or any repeated values. This utility is useful for slots that hold data that is often the same value and the user only wishes to see any changes to this standard value. The functionality is available on Series Slots, Agg Series Slots, Multi Slots, and Table Series Slots.

Series Display compression can be accessed from

When either of these options are chosen, the Open Slot window adds the display compression area between the scroll area and above the column heading.

Figure 4.16 identifies the configuration controls. Each control is described in detail.

On the Open Slot windows, the user can highlight a number of cells and type a new value that will be entered, as Input, into each selected cells. When Series Display Compression is enabled, the editing of values is treated a differently as follows:

On multi-column slots, (Agg Series, Multi Slots, Table Series Slots, and accounting slots), the Series Display Compression will only compress/hide a row if the compression is valid on all columns of the row. In Figure 4.17, repeated value compression only applies to a subset of rows.

On Series Slots, the Timestep I/O menu is used to change the status of the cell’s value by changing the flag. Possible flags vary by slot, but may include the following:

User-input data are automatically flagged as INPUT, and may not be overwritten by simulation results. Certain values imported by an input DMI are flagged Z for DMI INPUT and are treated identically to INPUT (I) flags. Initialization Rules can also set values with the Z flag. OUTPUT (O) timesteps may contain values calculated during a previous run or toggled from INPUT status. These values are automatically cleared to NaN at the beginning of a simulation run. This guarantees that no previous solutions remain from one run to the next. Simulation results are written to timesteps flagged as OUTPUT, TARGET BEGIN, BEST EFFICIENCY, MAX CAPACITY, SURCHARGE RELEASE, DRIFT and UNIT VALUES. Flags other than OUTPUT and INPUT are only available for certain series slots.

This section describes the use of special flags which may be set on Series Slot timesteps. The flags are typically set by the same mechanisms as INPUT and OUTPUT flags. But, unlike INPUT and OUTPUT flags, each type of special flag is only applicable to one or two slots. All SeriesSlots must have one of the following flags set for every timestep; each flag is indicated by its abbreviation:

Flags are set from the Open Slot window or from the SCT. In the Open Slot window, a flag is set on the highlighted timestep by selecting the flag from the Timestep I/O menu. Flags which are unavailable for that slot will appear dimmed in the menu.

The Timestep I/O menu has the following options:

BEST EFFICIENCY and MAX CAPACITY flags may be set on Energy timesteps instead of an INPUT Energy request value. These flags are used by the Plant Power Coefficient Release User Method to calculate the most efficient or maximum Energy generation possible for the flagged timestep.

The Plant Power Coefficient Release method uses tables to relate the current Operating Head to the most efficient Turbine Release or maximum allowable Turbine Release. The MAX CAPACITY flag is available for all power method except LCR Power Calc. The BEST EFFICIENCY flag is only valid for the following power methods:

The calculation of the best efficiency Energy generation or max possible Energy generation is an iterative solution. The Outflow required to produce the desired type of Energy affects Tailwater Elevation, which affects Operating Head, which affects the Outflow required to produce the desired Energy. See Power Release in Objects and Methods for details on this methods.

When an energy value has been calculated using a MAX CAPACITY or BEST EFFICIENCY flag and it is set as a user input for a subsequent run, a warning may be posted that says “Energy request cannot be met on current iteration.” This is due to the way RiverWare solves. When two reservoirs are modeled in series, the Tailwater Elevation of the lower reservoir affects the Operating Head of the upper reservoir. The Outflow of the upper reservoir, in turn, affects the Tailwater Elevation of the lower reservoir. This creates an iterative loop between the Outflow from the upper reservoir, the Tailwater Elevation of the lower reservoir, and the Operating Head of the upper reservoir. When an Energy value is set using either a MAX CAPACITY or a BEST EFFICIENCY flag, the reservoirs iterate over Outflow, Tailwater Elevation, and Operating Head until the values converge. If the Energy value is now set as an input and the model is run again, the Input Energy may not be possible given the Operating Head on the first iteration. If this happens a RiverWare warning is posted but the run does not abort, since the energy value MAY match the Operating Head at a later iteration. The Energy also MAY NOT match the Operating Head at a later iteration. If this occurs, the model will continue running even though the object did not solve. The run will NOT be aborted, but objects may not dispatch because required information was not propagated to them. The user must check the dispatch window if they receive the RiverWare warning message given above to make sure the model ran correctly.

As demonstrated in the simulation exercise, this flag computes the maximum possible Outflow from a Reservoir on a given timestep. Setting the MAX CAPACITY flag on a Reservoir Outflow slot forces the Outflow to equal the sum of the maximum (Turbine) Release and the maximum Spill.

The MAX CAPACITY flag is set by highlighting a simulation timestep on the Outflow slot of a Reservoir and selecting Timestep I/O, then Max Capacity. RiverWare places an M at the selected timestep to indicate that the flag is active. This flag is treated as an INPUT, but does not require a value. If a valid Outflow value is present at the flagged timestep, it is ignored in the simulation; a new Outflow value is calculated and displayed at that timestep. This behavior is similar to the Max Capacity and Best Efficiency flags of the Energy slot and the Drift flags of the Regulated Spill and Bypass slots. A Reservoir which has the Outflow Max Capacity flag set may dispatch under any of the “given Outflow” dispatch methods, as follows:

The Outflow Max Capacity flag may NOT be used on reservoirs when solving for Hydrologic Inflow, or when solving a Target Operation.

The Max Capacity solution is iterative. The exact sequence of calculations in each iterative loop is dependent on the type of Reservoir and the selected Spill Calculation Method. In all cases, the maximum Spill and maximum controlled Release are calculated individually, then summed. If the selected Spill Method includes Regulated Spill, the current or previous Pool Elevation is used to look up the maximum Regulated Spill from the Regulated Spill Table. This value is set in the Regulated Spill slot, and the selected Spill Calculation Method is called. Any input Bypass and/or required Unregulated Spill are considered within the Spill Method. Next, the maximum release is calculated. If the Reservoir is a Power Reservoir, the selected Tailwater method is executed to determine the Operating Head. This Operating Head or the Pool Elevation (in the case of Storage Reservoirs) is used to look up the maximum release from the Max Turbine Q table, Max Release table, Max Flow Through Turbines table, or Best Generator Flow table. Finally, the maximum release and the calculated Spill are added to determine the total maximum Outflow. This Outflow is used to mass balance the Reservoir. The iteration is repeated until Convergence is met or Max Iterations is exceeded.

Target Operations are used to calculate a lumped mass balance across several timesteps, in order to exactly meet a user-input TARGET Pool Elevation or Storage value. Three conditions are necessary for a Target Operation to execute successfully:

Given these conditions, RiverWare calculates the unknown Inflows or Outflows for all of the timesteps within the Target Operation, such that the TARGET value is exactly met.

Spill DRIFT is used to calculate the Regulated or Bypass Spill over a controlled gate as the reservoir Pool Elevation changes over time. The flag is always considered an input on any timestep where it is set but no value is initially set by the user. In this way, it is similar to the Energy BEST EFFICIENCY and MAX CAPACITY flags. Since DRIFT is considered an INPUT, it may affect over determination of Spill parameters.

The first timestep prior to initiating drift is used to determine a gate index called the Regulated (or Bypass) Drift Index. This index is interpolated from a 3-dimensional Regulated (or Bypass) Spill Index Table, which relates Pool Elevation to Spill for various gate indices. In all subsequent timesteps where the DRIFT flag is set, the same index is used to determine the new Spill. The gate index is maintained throughout the selected time period. At each timestep, the new value of Spill is calculated for the structure based on the current average Pool Elevation.

The SURCHARGE RELEASE flag is used to calculate the surcharge or mandatory release from a reservoir during flood control operations. Surcharge releases are meant to evacuate water from that sits above the top of the flood pool. This flag can only be set on the Surcharge Release slot which is only available when the user has selected a Surcharge Release method. The flag is always considered an input on any timestep where it is set but no value is initially set by the user.

Although the SURCHARGE RELEASE flag may be set by selecting Timestep I/O, then Surcharge Release from the Surcharge Release slot, in practice it should only be set by a rule. When the SURCHARGE RELEASE flag is set, and the inflow to the reservoir is known, the reservoir can dispatch with the Solve given Inflow, Outflow dispatch method. This dispatch method will calculate the forecasted surcharge releases and will set them on both the Surcharge Release and Outflow slots so that they may propagate downstream. The manner in which the forecasted surcharge releases are calculated depends on the method selected in the Surcharge Release category. If you are interested in using one of the surcharge release methods, see Surcharge Release in Objects and Methods for details.

The REGULATION DISCHARGE flag is used to calculate the regulation discharge at a Control Point. Regulation discharge is used during flood control operations and is defined as the maximum allowable flow in the channel at the control point. This flag should only be set on the Regulation Discharge Calc slot on Control Points. This slot is only available when the user has selected a Flood Control method and a Regulation Discharge method. The flag is always considered an input on any timestep where it is set but no value is initially set by the user. Like the SURCHARGE RELEASE flag, the REGULATION DISCHARGE flag should only be set by a rule. If you are interested in using one of the Regulation Discharge methods, see Regulation Discharge in Objects and Methods for details.

The UNIT VALUES (U) flag is used to indicate that the user is going to specify unit level values but would like to use those to drive the solution. The UNIT VALUES flag may be set on Energy or Turbine Release on power reservoirs that have the Unit Power Table method selected (see Unit Power Table in Objects and Methods). If the Unit Power Table method is not selected, an error is issued. This flag is considered a user input but does not require a value (similar to the MAX CAPACITY and BEST EFFICIENCY flag). At the beginning of the run any numeric values are cleared out. The flag can be set directly on the slot, from the SCT, or from a Rule.

In addition, Energy can be flagged U, if the reservoir dispatches one of the following methods:

These methods do not require Energy to be unknown.

This flag is specific to the Unit Power Table method; see Unit Power Table in Objects and Methods for full details on this algorithm.

The Find Series Slots with Inputs utility can be used to find values that are input in the model. It is accessed from the RiverWare Workspace using the Workspace, then Slots, then Find Inputs menu. The Search Slots window appears.

The user has options to filter on the types of series slots on which to look for input values. In a pure simulation model, this is only Physical Slots (i.e. Outflow, Inflow, etc.) If Accounting is enabled, the user may choose to search any or all of the following series slot “domains”:

The search may be limited to either Initialization Timesteps (before the Run Start timestep) or Run Period Timesteps (on or after the Run Start timestep). If both are checked, all series slots having any inputs are found, regardless of where (in time) those Input values are within the slots' time series.

The search operation is performed by selecting the Search button. The number of series slots with Input-flagged timesteps, and the total number of series slots matching the checked “domains” are indicated in a status line to the right of the search button. If search criteria is changed (by selecting any of the checkboxes at the top of the window), a green check icon is displayed next to the search button indicating that a new search with the new criteria has yet to be performed. The green check icon is hidden upon performing another search.

The user has the option of showing the slots' object name and account name (if applicable) in separate columns. This is controlled by the Compress columns checkbox below the slot list. This is not available if supply slots or exchange slots are shown in the slot list,

Several context menu (right-click) operations are available within the slot list:

Buttons along the bottom of the window provide these functions:

The window can also be used to find slot descriptions; see Slot Descriptions for details.

Expression slots are computational expressions. The user can either create a Series Slot with Expression or a Scalar Slot with Expression. They are used to calculate quantities such as “combined Storage of all Reservoirs,” “weekly average Outflow of Hoover Dam,” “the ratio of Hydrologic Inflow to Reach Inflow at selected structures”, or any conceivable expression. To add a Series slot with expression select Slot, then Add Series Slot with Expression.

Expression slots utilize the RiverWare Policy Language (RPL). RPL is computationally expressive language and has an associated structured editor. Because Expression slots utilize RPL (the same language in which RiverWare rules are written) they may contain simple expressions or complex logic and functions. Anything that may be expressed in a rule may also be evaluated in an Expression slot. The use of RPL also provides dimensional analysis to ensure that units are reconciled throughout the expression.

When first opened, this slot is shown in its own Slot Window so you can see and edit the expression or the data. A sample is shown in Figure 4.18.

The slot can also be shown in the Slot Viewer, with only the data shown. Use the File menu or drag the slot onto the viewer as described Slot Viewer Functionality. When this type of slot is shown in the Slot Viewer, there is special ornamentation in the column heading indicating its type, as shown in Figure 4.19, indicating there is an expression to edit or view. Click the icon to open the slot in its own window where you can see the expression.

Following is description of the configuration options available for expression slots. All of these menus can be accessed from the slot window. All but the Expression menu can be accessed from the Slot Viewer.

On the File menu, the Import options are not available as you cannot import or type data into the slot. The export options are available and can be used to export the calculated data out of the slot. A Print Expression menu option is available to print the expression. This uses the same printing mechanism as other RPL sets; see Printing in RiverWare Policy Language (RPL) for details.

On expression slots, the Edit menu has options to Copy (to the RiverWare clipboard) and Export Copy (to the system clipboard). Importing, pasting, and other data editing features are disabled as the expression slot is “output only”.

The View Menu on expression slots show the following menu options.

The Start and End times can be specified explicitly or symbolically as RPL DATETIMES; see DATETIME in RiverWare Policy Language (RPL) for details. Text below the editor field indicates the actual DateTime of the entered symbolic time text (if it is valid), or the status if it is not valid. You can also use the menu to specify one of the common DateTimes. Some of these are expressions that must be edited to become valid, e.g. by replacing “N” with a nonnegative integer and the HH:00 MMM DD, YYYY formula, where you substitute the hour, month, day and year.

The Datetime Editor option opens a separate window to specify the DateTime using a selector configured for the model's timestep size.

The RPL Function opens a Function Selector to select a RPL function in the Expression Slot or Global Function Set. The selected function must have a return type of DATETIME, and must not have any arguments.

Select Help (question mark icon button) on the right side of the symbolic DateTime editor to show a description of symbolic DateTime representations.

Expression slots utilize the RPL palette to build expressions. The RPL palette provides a syntax-guided editor designed to assist in the construction of complex syntactically correct expressions within the RiverWare Policy Language environment. The editor works by maintaining a partially constructed expression and allowing the user to manipulate unfinished portions using the palette. Initially, the buttons in the palette are grayed out. When building an expression, the palette enables any buttons that could possibly go in a highlighted portion of the expression.

See Editing a RPL Expression in RiverWare Policy Language (RPL) for details.

Diagnostics for expression slot evaluation can be configured in the Diagnostics Manager; see Diagnostics Manager in Debugging and Analysis for details.

If expression slots are evaluated outside of a run, using the Expression, then Evaluate menu on the slot or the Control, then Evaluate Expression Slots menu from the workspace, then diagnostics must be set up using the Workspace diagnostics; see This document is under development. in Debugging and Analysis.

If expression slots are evaluate during a run, either beginning or end of timestep or beginning or end of run, then diagnostics must be set up using Simulation diagnostics (see Simulation Diagnostics in Debugging and Analysis) or Rulebased Simulation diagnostics (see Rulebased Simulation Diagnostic Groups in Debugging and Analysis), depending on the selected controller. Within each of those diagnostics configurations, the Expr. Slot Execution and Expr. Slot Function Execution categories deal with expression slots.

The Text Series Slot holds a series of user-specified text strings. Because it is a series slot, it provides much of the required series slot functionality like display, flags, use in SCTs, and input via DMI. Figure 4.20 shows a sample Text Series Slot. It has comments about how the system is operated during July.

The following list provides information on supported functionality:

As of version 7.4, the following functionality is not supported:

Aggregate Series Slots (Agg Series) are specialized Series Slot that group together one or more Series Slots which are independent of one another. They are used to group together similar series of data. Agg Series slots are essentially multiple individual series of data. The columns of an Agg Series Slot are often referred to as Sub Slots. Figure 4.23 shows the Evapotranspiration Rate by Crop for two different crops, Corn and Wheat.

Following are configuration options specific to Agg Series Slots. See Configure Slot Dialog for details on general configuration. See Configure Slot Functionality for details on Series Slots.

Agg Series slots can be configured such that each column is configured identically or each is configured individually using the appropriate View menu Configure Columns Identically or Configure Column.

Because each column can be configured separately, the time range of each column can be configured to have different start and end dates. The two options allow the columns of the agg series to sync back together:

Integer Indexed Series Slots and Integer Indexed Agg Series Slots are specialized types of series slots whose range is associated with their order in the series, rather than with dates. The indices are 1-based; that is, the first value has index 1.

Configuration of Integer Indexed Series Slots is similar to Series Slots, but because the series is incremented by integer, there are a few differences between this type of slot and a standard series slot. See Configure Slot Functionality for details.

The View menu has a Series Range menu instead of the standard Timeseries Range menu option. In the Series Range menu (the Configure Series window), the Begin, End, and timestep areas are disabled. The user can change the range only by changing the number of values.

Integer Indexed Series slots can be used as a part of the following utilities:

Series Slots with Periodic Input allow you to specify either a series of values or a periodic relationship. You can specify data in one of the following Input Modes:

Series Slots with Periodic Input behave as ordinary series slots in virtually all ways, including RPL access, plotting, outputs, etc. A minor exception to this is that DMI import operation to these slots is blocked when they are in Periodic input mode.

Series Slots with Periodic Input can be shown in either the slot window or the Slot Viewer. When the slot is in periodic mode, it opens in its own slot window. When the slot is in series mode, it opens in the Slot Viewer and there is special ornamentation in the column heading indicating its type, s shown in Figure 4.24. Click the icon to open the slot in its own window where you can see the periodic input values.

In general, when switching a Series Slot with Periodic Input from Series to Periodic input mode, the existing series values are lost; they are overwritten with values computed from the periodic input definition. When switching from Periodic to Series input mode, the periodic input values are hidden and become inactive.

The remainder of this section describes creation and editing of these types of slots.

Series Slots with Periodic Input exist on some engineering objects (particularly the reservoirs) and can be created by the user. From the Object window, choose the Slot, then Add Series Slot with Periodic Input menu item.

Following are configuration options for this type of slot.

Series Slots with Periodic Input start in Series input mode where they appear and behave as ordinary series slots. Figure 4.25 shows Series input mode.

The slots are accessed from RPL using standard series syntax, i.e. by DateTime: Slot[ ] or Slot [E].

In Periodic input mode, the series data is shown as read-only (cannot be edited), but an editable periodic data panel is shown to the right (see Figure 4.25). Edits and operations on the periodic values immediately cause a recalculation of the series values—assigned as Inputs except where periodic values are undefined, in which case NaNs (flagged as Outputs) are shown. Series values are computed for the series slot’s currently configured time range.

The periodic configuration is accessible from the View, then Configure Period menu. See Periodic Slots for an explanation of the available period, interval, and data interpolation settings. Use the options in the Row menu to modify the rows of the periodic table.

Although they have periodic data, the slots are accessed from RPL using standard series syntax, i.e. by DateTime: Slot[ ] or Slot [E].

In general, when switching from Series input mode to Periodic input mode, the series values are overwritten by values computed from the periodic values. When series values are overwritten by periodic data, the you must confirm the warning dialog. No confirmation dialog is shown when switching from Periodic input mode to Series input mode, as there is no loss of data in that change.

In general, when changing the display units of a Series Slot with Periodic Input, the values in a both the Series and entries are converted to the new units. But when in periodic mode and the new or existing unit involves a non-constant timestep length, for example, per month or per year, the series values must be recomputed from the converted periodic values. The recomputed series values will then match the periodic values. A warning message is posted to a dialog and/or the diagnostics output when this occurs.

Multi Slots are specialized series slots that automatically sum the values of the slots to which they are linked. In the screenshot, two series slots named Gage Above Bartlett. Gage Outflow and Reach2.Outflow are linked to the Bartlett.Inflow slot. Each of the linked slots appears in a column. The cells for these columns are grey hatched indicating that they are not directly editable from this view. The user should edit these values from the other end of the link. The sum of all linked columns is reported in the Total column. The columns of a Multi Slot are often referred to as Sub Slots. All of the sub slots must have the same unit type and user unit although the other end of the link can have a different user unit, conversion is automatic.

Configuration of Multi Slots is similar to Series Slots; see Configure Slot Functionality. On Multi Slots there is a toggle at the bottom of the window that is used to hide or show the subslots. The checkbox is shown only if the Multi Slot has at least one subslot. It is initialized to OFF if the Multi Slot has exactly one subslot, otherwise, it is initialized to ON. This can be useful for subslots that only have one link, hence it really only represents one series of data.

Table Slots are used to store any table of data. They can define a curve (2-Dimensional), a surface (3-Dimensional), or several unrelated sets. A 2-Dimensional table may require monotonically increasing values in its first column, as shown in the Elevation Volume table.

See View Menu for details on configuring Table Slots. Each column of the table has both a Label and a Unit (user units are configurable). On simulation slots, the Rows are labeled by number unless defined otherwise. Both columns and rows are zero-based, i.e. the first column is column 0. On custom slots the user is able to change both the Units, Display Format, Column Labels, and Row Labels. Table Slots can be configured such that each column is configured identically or each is configured individually. In the View menu, there is a menu to Configure Columns Identically or separately using the Configure Column menu on the selected column.

A 3-Dimensional table requires that column 1 contain sets of equal values which increase down the table, and column 2 must contain monotonically increasing values within each set of values from column 1. Column 3 then contains the values to look up for columns 1 and 2. For example, the Stage Flow Tailwater Table is a 3-Dimensional table relating TW Elevation to the independent variables of reservoir Outflow and Downstream Stage. A set where Outflow is equal to 20,000 cfs is highlighted.

Some specific scalars and tables have a “Source” slot. When a slot has a source slot, the values are computed from the source slot’s values. Thus, the destination slot becomes read-only and displays a cross hatch over the data. The slot also provides a note indicating the source slot used to compute the data. The source slot is typically set/un-set at beginning of run, so you must initialize the run to see the read-only status.

Table slots include an option to export to a comma-separated values (CSV) file. This option is available from the File menu in the slot window.

The data will always be exported to the CSV file with display precision. The first column of the CSV file will be the row labels of the table slot. The first row of the CSV file will be the column labels of the table slot with units included in parentheses.

Exporting of a table slot to a CSV file can also be automated with a script action. See Export Table Slot as CSV in Automation Tools.

Statistical table slots compute statistics of values for a series slot, such as a flow duration curve. The statistics are computed interactively or at the end of a run and can then be plotting, exported, or used in reports.

A fully configured statistical table slot it shown below.

The numbers in the figure above are as follows:

The body of the slot then contains columns representing the specified statistical computations. See Statistical Functions for more information on the available computations.

To create a statistical table slot, open the desired object. From this window:

A statistical table slot will be displayed in the slot list with this icon: .

From the object, double click to open the statistical table slot. The following screenshot shows the slot:

It starts off blank. Select the highlighted gear icon to select the statistical function and the slot to analyze. See the next section for more information.

The basic steps in configuring a statistical table slot are:

By default, all statistical table slots will be cleared at the beginning of the run and evaluated at the end of the run.

The contents of a statistical table slot can also be cleared and evaluated manually.

Snapshots can be made of statistical slots to easily preserve and compare their values from different runs.

The contents of a statistical table slot can be plotted.

A statistical slot can be plotted with all of its snapshots.

User data input to a table slot can be plotted with a statistical slot.

The contents of the statistical table slot can also be exported to a text file for analysis using an external tool.

Statistical table slots include an option to export to a comma-separated values (CSV) file. This option is available from the File menu in the slot dialog box.

The data will always be exported to the CSV file with display precision. The first column of the CSV file will be the row labels of the statistical table slot. The first row of the CSV file will be the column labels of the statistical table slot with units included in parentheses.

Exporting of a statistical table slot to a CSV file can also be automated with a script action. See Export Table Slot as CSV in Automation Tools.

On the statistical slot configuration, select how to compute the exceedence percentage P sometimes called the Plotting Position. The following image shows the options for some statistical functions. Mouse over the “i” icon to see a tool tip showing the computation.

This exceedence computation is called Interpolation as the P values are interpolated from the bounding items.

The following applies to all statistical functions except Partial Duration Max/Min Frequency Curve.

Another way to write this is:

For Partial Duration Max/Min Frequency Curves, the Interpolated P is:

Another way to write this is:

This exceedence percentage is computed as follows:

The Weibull exceedence percentage is computed as follows:

The Median exceedence percentage is computed as follows:

The Hazen exceedence percentage is computed as follows:

The following statistical functions are provided.

In the statistical function configuration for this function, there are the following options:

The following figure shows the Exceedence Probability selector.

The following steps are performed:

Qy = the value having an annual exceedence probability

m = mean of the logarithms of the annual values

s = standard deviation of the logarithms of the annual values

Ky = frequency factor for the given exceedence probability

Below the data table, the following summary statistics are presented:

Use the File and then Plot with Source Slot menu option to create a new plot containing both the Log-Pearson Type III Distribution statistical table slot and its input slot. When this option is selected, the Plot Table Slot dialog that appears allows the user to select which columns should be assigned to the X and Y axes independently for both slots. With additional configuration, the plot can look like the following:

Table Series Slots are a specialized table slot whose rows correspond to timesteps. This slot contains limited timeseries functionality thus making it more efficient than Series Slots. It was created as a way to efficiently write and/or read large amounts of data. Table Series Slots are primarily used within object user methods such as the Muskingum Cunge hydraulic routing methods. These types of slots cannot be created as custom slots.

Periodic slots are tables used to represent periodic data which repeats at regular time interval. An example might be a set of evaporation coefficients for a reservoir. The rate of evaporation varies with such factors as temperature and wind speed, factors which vary seasonally. It is natural to assume that this variation is the same for each year. If this sort of data were entered into a series slot, then the same data would need to be repeated every year. This would be impractical and inconvenient for the user. On the other hand, if this data were entered in to a table slot, then the data would lose the time element associated with each value. This would make it difficult to look up or interpolate values with respect to time. The periodic slot solves both of these problems.

Periodic slots are configured in the same way as other slots, by using the View, then Configure menu.

The upper left portion of the Configure Slot dialog, under the Period section, is used to set the period and interval of the periodic slot. The period can range from 6-hours to several years while the interval depends on the period selected. If the period required is more than 1 year, the Qty value should be modified from 1 to the number of years and the Base year—the first year in the period—should be defined. Base year can be specified explicitly or symbolically using the menu. If not specified explicitly, they must be edited to become valid, e.g. by replacing the “N” with a nonnegative integer or “YYYY” with a year. Text below the editor field indicates the actual year or indicates the entry is invalid. The Help button provides more information on legal DateTimes.

Also notice the checkbox next to Regular Interval. If the data interval is not a consistent length of time, the user can clear this option and the periodic slot would then have an irregular interval. The user is then free to configure the rows/timesteps in any fashion. See Display of Dates for details.

The Data Access section located in the upper right portion of the Configure Slot dialog is used to specify whether or not data should be interpolated or looked up directly when accessing the table at a time that is not specifically listed as a row label. For example, the monthly data is shown for the beginning of each month. If we’re in the middle of the month, should we use that same piece of data, or should we interpolate between the two months? This is a question that would need to be answered on a per model basis, however, the default behavior is a direct lookup.

Columns can be added/deleted by selecting a column and using the Column menu.

The rows of a periodic slot represent dates and are displayed differently if the interval is Regular or Irregular. This distinction in dates is described below.

For Regular intervals with a 1 day or smaller period, the row labels indicate the intervals, down to the minute, for which the values apply:

For Lookup, above left, the rows show the time including the second. This indicates the beginning of the interval.

For Interpolation, above right, the rows show the instant in time at which the value applies. Remember 0:00 is the same as 24:00 of the day before. Thus 0:00 Jan 1 is the value that will be used for 24:00 December 31.

Periodic slots are create as one of the two following types:

In this mode, the periodic slot simply contains columns of data that may or may not be related. There can be no interpolation across columns.To add a periodic slot with Text Headers:

Columns of Periodic Slots with Text Headers can be rearranged using the Column, then Move Columns menu (custom slots only).

Consider a periodic slot containing loss coefficients. The periodic slot may contain loss coefficients that vary not only with time, but also with flow rate in a reach. RiverWare could identify which coefficient to use by indexing the table row using the current time step and the table columns using a flow rate. The user could specify as many columns as necessary to sufficiently describe the variation of loss coefficients as a function of flow rate. The periodic slot’s Column Units would be configured to be flow, perhaps with units of 1000 cfs.

To add a periodic slot with Numeric Headers:

The dialog has a Column Units section. This may be useful if the columns are indexed using numeric header values and the values have some physical (not simply descriptive) significance. The unit specification uses the unit type settings for the active Unit Scheme; see Editing Attributes for details.

The periodic slot can be used backwards to work from the table values and date outward to define a value associated with the column(s). For example, suppose the periodic slot defines the various pools or phases in a reservoir. The conservation pool may be defined as phase 1 with the first column containing pool elevations defining the conservation pool throughout the year. This first column would have a header of 1.0, meaning phase 1. The flood pool may be phase 2.0 with a second column using 2.0 as its header. The surcharge pool may be phase 3.0, etc. Knowing the pool elevation at a given time, the periodic slot can be used to determine the current phase. Interpolating across columns, this outward lookup may determine that the current phase is 2.5 for a given pool elevation and date, meaning pool is halfway from the bottom of flood pool to the bottom of the surcharge pool.

In RPL, periodic slots are referenced using the Slot[E, E] syntax. Like other tables, this is a row by column reference. But, because it is a periodic slot, the row is a DateTime: Slot[<DateTime>, E]. When referenced in RPL, the configuration of the slot will be used when accessing dates that are “between rows”. That is, it will either interpolate or look up depending on the slot’s configuration.

For periodic slots with text headers, the column specification is a text string matching a column or the zero-based column index. For periodic slots with numeric headers, the column specification is a numeric value with units. You can specify any number that falls within the min and max column values. That is, you don’t have to specify an exact column’s value, but can use numeric values that are “between columns” and it will linearly interpolate for you. For example, the slot shown in Table 4.2 represents low flows that are based on reservoir levels. It is configured to lookup.

In RPL, to reference this slot on January 15 for reservoir elevation 5002ft, the following would be used:

It would return the following:

Periodic slots include an option to export to a comma-separated values (CSV) file. This option is available from the File menu in the slot dialog box.

The data will always be exported to the CSV file with display precision. The first column of the CSV file will be the date row labels of the periodic slot. The first row of the CSV file will be the column labels of the periodc slot with units included in parentheses.

Exporting of a table slot to a CSV file can also be automated with a script action. See Export Table Slot as CSV in Automation Tools.

Scalar slots represent a single value. Configuration options include units and display format. Scalar slots are used only for input data parameters. See View Menu for details on configuring slots, including Scalar Slots.

Scalar slots open by default in the Slot Viewer (Scalar) but you can show them in their own Open Slot dialog box by undocking them. Figure 4.30 highlights the differences between the individual Slot dialog and the Slot Viewer. Following the figure are FAQs that compare and contrast the two interfaces.

See Slot Viewer (Scalar) and Scalar Slot Dialog Functionality

The Slot Viewer (Scalar) provides a compact display of multiple scalar slots simultaneously. It is the default view for scalar data in the same way that the Slot Viewer is the default view for time series slots. The Slot Viewer (Scalar) supports the following functionality:

The Slot Viewer (Scalar) contains a table of slots containing scalar data, a set of controls to display and manipulate the selected slot's data, and a standard menu bar. Figure 4.31 shows the Slot Viewer (Scalar) containing a variety of slots and data types.

The following operations are not supported on the Slot Viewer (Scalar), but are supported from the Scalar Slot dialog:

Open the Scalar Slot dialog first to perform these operations.

The scalar slot dialog, i.e. the Open Slot for Scalar slots, was the original interface and previously the only way to view and configure scalar slots. Figure 4.32 shows a view of the dialog and all of the pieces. This dialog shows one slot and one scalar value. Use the View and then Configure menu or button to change the settings of the slot. The configuration settings are similar to the general open slot described in Configure Slot Dialog.

The menu bar operations also support the ability to:

Some specific scalars and tables have a Source slot. When a slot has a source slot, the values are computed from other slot values. Thus, it becomes read-only and displays a cross hatch over the data (see Figure 4.33). It also provides a note indicating the source slot used to compute the data. The source slot is typically set at the beginning of run, so initialize the run to change the read-only status.

This slot, similar to the Series Slot with Expression, is used to evaluate an expression that evaluates to only one value, i.e. timestep independent. See Series Slots With Expression for details on Series Slots with Expression, as much of that information is valid here too. The difference is that the scalar expression slot does not have an Evaluation Range, it will evaluate for the single value only. Like the series expression slot, configure when it evaluates. Use the Expression, then Evaluation Time menu to choose.

The Scalar Slow with Expression always opens in its own dialog box so you can see the expression. You can drag the scalar slot icon onto an existing Slot Viewer (Scalar) or use the File and then Dock in Slot Viewer menu.

The Mass Balance Summary slot is a user-defined hierarchy of series slot collections used to check (i.e. sum) mass balance across many objects. The collections are themselves series slots representing the sum of the contained slots. These slots can be used within RPL expressions and any other place where series slots are used.

There are two levels of within a Mass Balance Summary slot:

Figure 4.35 shows the icons for the Mass Balance Summary Slot and the Computed Mass Balance Slots (i.e. Water Balances and Slot Sums).

The Computed Mass Balance Slots are computed:

Also, a list of RPL expression slots to be evaluated after a Mass Balance Summary slot computation can be specified within the summary definition. For example, this can be used for annualization of mass balance summary results.

The screenshot shows the dialog for a Mass Balance Summary Slot. Colors are associated with the three collection levels:

The color buttons at the top of this dialog function as a legend for the three levels. Also, selecting those buttons open the tree items in the list to the corresponding level. Also individual collection items can be opened and closed in the usual way, by selecting the tree controls.

Finally, the slots can be shown in any user units and plotted as needed.

A Mass Balance Summary Slot can be created by selecting the Add Mass Balance Summary operation.

The name of the new Mass Balance Slot can be edited in the dialog. When the entered name is not valid, the text in the name entry field is shown in red.

Editing the configuration of a Mass Balance Summary Slot can be enabled or disabled. It is initially enabled on a newly created slot. Editing can be enabled or disabled with the following controls:

Right-clicking the list outside of any defined items (e.g. when the list is empty) shows a simple context menu including the Add Water Balance operation.

The buttons along the bottom of the dialog are also context sensitive; that is, their operation and enabledness depends on the selection within the slot list. When no items are selected, the New button also adds a water balance to the list.

When new Water Balances or Slot Sums are created, they are given a unique default name. The name can be edited inline by double-clicking the name.

Slot Sums can be added to Water Balances, and Slot References can be added to Slot Sums using the Add context menu operation or the bottom context buttons.

When adding Slots, the slot selector dialog is shown. This will allow the selection of only series slots. The slot selector’s unit type filter will be shown, initialized to “Flow”. It is also valid to select “Volume” slots which represent a non-static volume entity; that is, those that can be converted to “Flow” by dividing its value by the timestep interval (i.e. volume per time). (The computed results will be strange if a static volume slot, such as Reservoir Storage, is selected).

Alternatively, slots representing mass units (g, kg, tons, etc) can be chosen. This is particularly useful when looking at the salinity mass balance across many objects.

Figure 4.36 shows the operations provided by the first several buttons, as a function of the selected item or items. Tooltips on these buttons provide additional information.

The New, Add, and Paste operations are enabled only for single-item selections. The Delete, Remove, and Copy operations are enabled on single or multiple selections when all selected items are at the same level. The enabledness of the Paste operation depends also on the type of items (Water Balances, Slot Sums, or Slot References) in the clipboard. You must confirm Delete / Remove operations.

The Up and Down arrows move the selected items up or down within the set of “sibling” items. They are enabled only when the selected items are all at the same level.

The and buttons affect the Slot Sums within the set of selected items.

For any value not provided as a RiverWare slot, you will need to define and refer to a RPL expression slot. Figure 4.37 is an example of the inclusion of a change in storage expression slot from the previous to the current timestep.

The Mass Balance Summary Slot dialog shows a single timestep value of all contained series slots.

In this dialog, series values have the following options:

The selected unit type, scale and unit is both a display setting and a configuration setting; when the mass balance summary is computed, the computed slots are shown with these units. Precision can be set from the View, then Set Precision menu.

In fact, changing the unit, scale, or precision from this dialog actually changes the active Unit Scheme (by adding exceptions). You can also change the settings from the Unit Scheme Manager by changing attributes or activating a different scheme. See Unit Schemes for details.

As previously mentioned, the level Legend buttons function to open the entire tree to the indicated level. Of course, individual tree items can be opened or closed by selecting the standard tree controls.

The View menu provides operations that affect data display within this dialog.

The units column in the slot list can be hidden. But, if slots having different unit types (other than flow/volume or mass) are added to the list, units are unconditionally shown and the option to hide the units column is disabled.

You may want to hide values at any of the levels, so that only comparable values (at the same level) are displayed. The three Show Series Values toggles in the View menus are used to show or hide the numeric values; Figure 4.39 illustrates.

From the Open Mass Balance Summary Slot dialog, you can perform the following operations:

These options are described in the following sections.

As currently implemented, Water Balances are generated as aggregate series slots and each of the Water Balance’s Slot Sums are generated as series slot columns on that aggregate. Use the Open Slots context menu to show the slot dialog for the selected component (editing disabled).

Values are displayed with a crosshatch indicating that they are “read-only” (non-editable). In Figure 4.40, the not-quite-zero value in the “Value” line edit field from the single selected cell (upper left cell); this sort of value will be typical of actual computed Water Balance values (due to convergence). Enabling the display of the selection statistics (from the View menu) and selecting the first column provides a convenient way to determine whether or not the whole Water Balance series is zero.

Computed summary and referenced slots can be shown in an SCT. If a single SCT is open, slots from the Mass Balance Summary dialog can be added to that SCT (the SCT must have the same timestep size as the model run).

The File menu Show Visible Slots in New SCT option shows all slot items current visible in the slot list (i.e. excluding those hidden under a closed tree branch).

Computed summary and referenced slots can be plotted in a single plot. Those operations are visible in the menus shown in the prior section. The note above regarding the active units of computed and referenced slots applies also to Plots; that is, the units used will not necessarily be those of the current settings in the Open Mass Balance Summary slot dialog.

Computed summary and referenced slots can be copied to the RiverWare Slot Clipboard. From there, they can be pasted into various slot lists in RiverWare, including the general Output Device slot list and the Snapshot Manager slot list.

The Mass Balance Summary Slot is itself a series slot and can be examined by selecting the Mass Balance Summary Slot icon button at the top of the dialog. (In a sense, a Mass Balance Summary Slot has two different open slot dialogs).

In Figure 4.41, all the values represented on the vertical axis are zero (to a precision of five fractional decimal digits).

Mass Balance Summaries are designed in such a way that intermediate and final sum results (Slot Sums and Water Balances) are usable for custom user calculations implemented in RPL Expression Slots, such as annualization of values. In a run, the mass balance summary is computed after RPL Expression slots. To allow RPL expression slots to reference mass balance summary data, the Dependent Expression Slot List in a Mass Balance Summary is evaluated, in order, once, after each Mass Balance Summary is computed.

Dependent Expression Slot results will generally be incomplete when computing a Mass Balance Summary if the RPL Expression Slots in the list depends on sums from multiple mass balance summaries. The following provisions address this problem:

The Dependent Expression Slot panel at the bottom of the Open Mass Balance Summary Slot dialog implements editing and display operations similar to those of the main slot list.

Selecting the Add button opens the slot selector, initialized with Has RPL Expression and Unit Type (“Flow”) filters on by default.

When computed, the timestep size and timestep range of each of the Mass Balance Summary and Slot Sums are set to the step size and range of the run controller. The unit type and configured display units are set to those specified. For each timestep in the run time range, any of the contained slots having a valid value at that timestep contributes that value to the Slot Sum or Water Balance’s value at that timestep. NaNs are ignored (effectively zero). The computed slots are set to be “read-only”.

Limitations of the current Mass Balance Summary Computation:

Mass Balance Summary Computations are performed in these ways:

As a tool for debugging and testing Mass Balance Summary implementations (including user definitions), operations to clear an individual Mass Balance Summary, and all Mass Balance Summaries (including Dependent Expression Slots) is provided in the File menu.

All Mass Balance Summary configuration information is stored on the Mass Balance Summary Slot. This is applied both in the RiverWare model file and in Export files.

A Mass Balance Summary Slot’s computed slots are created as (effectively) invisible slots on the same object. They do show up in the slot selector!

A Mass Balance Summary Slot’s configuration can also be saved to, and read from a file using Export and Import operations in File menu.

Time Aggregation Series Slots temporally aggregate another series slot. For example, you might aggregate a daily flow to an annual average. They can be recomputed manually or automatically at the end of a run. The configuration of a Time Aggregation Series Slot includes the following properties. Figure 4.42 illustrates.

Functionality is provided to duplicate a Time Aggregation Series Slot for the same named slot on multiple other “similar” objects.

Once created (from the Object’s Slot, then Add Time Aggregation Series Slot menu), open the slot dialog to configure the slot. Configuration controls are available in a separate dialog which is shown by selecting the Configure icon .

One of the supported aggregation modes is aggregation to Water Years, starting in a user-specified month.

The Water Year Start Month is a model-wide setting, configured in the Settings Manager and then Run Parameters page. see Run Parameters for details.

In a single operation, you can create a Time Aggregation Series Slot for the aggregation of the same series slot on multiple other selected simulation objects. For example, if a given time aggregation slot is annually summing the Energy slot on a power reservoir, similar aggregation slots can be created for all other power reservoirs, in a single operation. Figure 4.43 shows an example.

When a properly configured Time Aggregation Series Slot item is selected within an Object’s slot list, the Create Similar Slot for Different Objects operation under the Slot menu is enabled. Activating that menu item brings up the simulation object selector dialog where multiple objects can be selected. The selector is initialized to show objects of the same type as the object containing the reference slot (e.g. in this example, Power Reservoirs). Ultimately though, you can select a broader range of simulation objects.

The names of the new slots are devised as follows: If the originally selected time aggregation slot's name contains the name of the referenced slot's containing object, then the new names are that name, with the original containing object name replaced by the new selected objects. In the example, the original time aggregation slot named “Monthly Energy” is aggregating the “Kaw.Energy” slot. However, the originally selected time aggregation slot's name does not contain the name of the referenced slot's containing object, no direct name substitution is possible. Instead, the names of the new selected objects are appended to the slot name for the new slots: Monthly Energy_Eufaula, Monthly Energy_Hudson, and so forth.

Time Disaggregation Series Slots temporally disaggregate another series slot into a smaller timestep. For example, you might disaggregate a daily flow to an hourly flow using the same value for each hour in the day. They can be recomputed manually or automatically at the end of a run. The configuration of a Time Disaggregation Series Slot includes the following properties. Figure 4.44 illustrates.

Functionality is provided to duplicate a Time Disaggregation Series Slot for the same named slot on multiple other “similar” objects as described in Creating Similar Time Disaggregation Series Slots for Different Objects.

Once created (from the Object’s Slot, then Add Time Disaggregation Series Slot menu), open the slot dialog to configure the slot. Configuration controls are available in a separate dialog which is shown by selecting the Configure icon .

In a single operation, you can create a Time Disaggregation Series Slot for the disaggregation of the same series slot on multiple other selected simulation objects. For example, if a given time disaggregation slot is disaggregating the Pool Elevation slot on a power reservoir, similar disaggregation slots can be created for all other power reservoirs, in a single operation. This operation is identical to creating similar time aggregation slots for different objects. See Creating Similar Time Aggregation Series Slots for Different Objects for more information.

A List Slot is used to store a collection of non-numeric data, typically a group of objects. Figure 4.45 shows a sample Upstream Reservoirs List Slot.

This slot contains the Reservoirs that are upstream of the given control point. It is used in the Regulation Discharge and Flood Control algorithm to specify the reservoir which contribute to the flow at this control point. Figure 4.46 shows the options available from the Edit menu, from the toolbar icons, and from the right-click context menu:

On a List Slot that contains either Objects, Slots, Accounts, or Supplies, when the user selects either Append Row, Insert Row Before, or Edit Row, a selector will open allowing the user to choose the appropriate items.