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The user can use Future Editor (such as Edit in Figure 2) to set up the parameters of the farm dam. Clicking on Edit from the selected farm dam node will open the farm dam editor (Figure 4)
Figure 4 Farm dam editor – Dam Information
(1) The farm dam information
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- Diversion Fraction - decides how much the “upstream” flow, which includes both the upstream flow and interstation inflow, will be involved in the water balance calculation in the edited farm dam. The remaining water in the “upstream” flow will be diverted directly to the downstream flow.
- Bypass Flow - defines the maximum capacity of the flow bypass from the “upstream” flow directly to the downstream of the farm dam.
- Dam Surface Area Options - provides three options for the dam surface area during the water balance calculation:
- Constant dam surfaces area using ‘Max. Dam Surface Area’ parameter – The entered constant value of Dam Surface Area is used in water balance calculation such as converting rainfall and evaporation from the depth to volume in the farm dam storage.
- Allow dam surface area to vary according to dam volume - The area will be calculated on the basis of the storage volume, default equations and parameters. The storage volume is from the beginning of the time step. The calculated dam surface area at each time step will be used in water balance calculation. Custom Equation Parameters check box is unticked.
- Custom Equation Parameters – This function works only when the option Allow dam surface area to vary according to dam volume is selected and the Custom Equation Parameters check box is ticked. The dam surface area will be calculated based on the storage volume at the beginning of the time step, and the equation of Volume =A*Area^B. Where A and B are input parameters from the Interface. The calculated area at each time step will be used in water balance calculation.
Figure 4 Farm dam editor – Dam Information
(2) Interstation Flow:
Inflows into a farm dam in this farm dam model come from two alternative sources: (i) overflows from the upstream dam(s) and (ii) the local flow generated by the interstation area between the upstream dams and this dam.
Clinking on the Interstation Flow in the left panel of Figure 4 will display the Interstation flow parameters in the right panel for the configuration (Figure 5). The parameters include Scaling Factor and Reference Timeseries Values/Data Source. The user can select the option Values for the constant value or Data Source for a timeseries defined in Source Data Sources.
The interstation inflow is calculated based on a reference value or time series (i.e., at a flow gauge) that has been scaled down/up. If the scaling factor is 0.8 and the reference timeseries value is 0.25 ML/d, the Actual Interstation Flow (ML) is 0.2 ML/d. The scaling factor reflects (a) the interstation catchment area relative to the reference catchment area; and (b) the nonlinear relationship between the catchment area and flow.
Figure 5 Farm dam editor – Interstation Flow
(3) Seepage
Seepage from the farm dam into the underlying soil can be modelled by defining an exfiltration rate (e.g., mm/d). The water that seeps from the farm dam is lost from the catchment and does not re-enter the system downstream.
Clinking on the Seepage in the left panel of Figure 4 will display the Seepage parameter in the right panel for configuration (Figure 6). The parameters can be configured by the constant value or time series from Data Source.
Figure 6 Farm dam editor – Seepage
(4) Demand
Clinking on the Demand in the left panel of Figure 4 will display the demand parameters in the right panel for configuration (Figure 7). The demand parameters include Demand Factor and Demand Timeseries Values/Data Source. The demand factor can be estimated from the ratio of the average annual demand of the farm dam volume.
In this farm dam model, the demand is not directly using Demand Timeseries. The demand volume is determined by the demand factor and farm dam volume, and its temporal distribution is determined by the Demand Timeseries Values/Data Source.
Figure 7 Farm dam editor – demand
(5) Rainfall
Clinking on the Rainfall in the left panel of Figure 4 will display the rainfall parameters in the right panel (Figure 8). The parameter is the rainfall to the edited farm dam, and it can be configured by constant Values or timeseries data in Data Sources. Its unit is depth such as mm, and Source will convert it to volume by the dam area calculated as the description in section (1) The farm dam information.
Figure 8 Farm dam editor – Rainfall
(6) Evapotranspiration
Clinking on the Evapotranspiration in the left panel of Figure 4 will display the evapotranspiration parameters in the right panel (Figure 9). The parameter is the evapotranspiration from the edited farm dam, and it can be configured by constant Values to timeseries in Data Source. Its unit is depth such as (mm/day) and Source will convert it to volume using the calculated dam area as the description in section (1) The farm dam information.
Figure 9 Farm dam editor – Evapotranspiration
Clicking on the OK button in Figure 4 will save the setup of the farm dam. The Cancel button will discard the entered parameters.
For all Onstream Farm Dams nodes
Source allows inputting, editing, checking, and outputting all parameters of all farm dams together. Tool menu item Edit » Feature Table... can access Feature Table for this functionality (Figure 10). Clicking on the Onstream Farm Dam in the left panel (Figure 10) will display the existing values of all editable parameters for all onstream farm dams in the right panel.
The Feature Table headlines of all parameters are the same as (or similar to) those names described in the above section of For an individual node of Onstream Farm Dam except for four headlines below:
- Dam Surface Area Calculation – which only has two values for selection: Constant or Variable. The value of Constant indicates the option of Constant dam surfaces area using ‘Max. Dam Surface Area’ parameter (Figure 4) will be used in the water balance calculation. Variable indicates the option Allow dam surface area to vary according to dam volume (Figure 4) will be used in water balance calculation.
- Is Custom Param – shows the value of the check box Custom Equation Parameters (Figure 4). Its value only works when Variable is selected in the column Dam Surface Area Calculation.
- SA-Volume EQN A Factor - the value for A Factor (Figure 4). Its value will be used only when Dam Surface Area Calculation column is Variable and Is Custom Param is ticked.
- SA-Volume EQN B Factor - the value for B Factor (Figure 4). Its value will be used only when Dam Surface Area Calculation column is Variable and Is Custom Param is ticked.
The user can directly edit all parameters from Feature Table.
Figure 10 Farm dam configuration for multiple farm dams through the Feature Table
Recorders of Onstream Farm Dam node
Some recorders for the onstream farm dam in Source are described below to clarify the difference between the similar recorders.
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Recorder
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Description
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Note
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Bypass Flow (ML/d)
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The input parameter of the capacity of bypass in the current farm dam.
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Actual bypassed flows (ML)
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The real bypass flows in the time step from the bypass way in the current farm dam.
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Interstation Flow Reference series (ML/d)
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The input Reference data for Interstation Flow.
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Actual Interstation Flow (ML)
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The real Interstation Flow in the time step to the current farm dam, and its value is the product of the Scaling Factor and Interstation Flow Reference series.
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Evapotranspiration (mm/d)
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The input data of evapotranspiration from the current farm dam.
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Actual Evaporation Volume (ML)
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The real evaporation volume in the time step from the current farm dam and its value is based on the dam surface area and inputted Evapotranspiration (mm/d) in the time step.
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Rainfall (mm/d)
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The input data of rainfall to the current farm dam.
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Actual Rainfall Volume (ML)
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The real rainfall volume in the time step to the current farm and its value is based on the dam surface area and inputted rainfall (mm/d) in the time step.
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SeepageTS (mm/d)
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The input data of seepage from the current farm dam.
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Actual Seepage (ML)
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The real seepage volume in the time step from the current farm dam and its value is based on the dam surface area and inputted SeepageTS (mm/d) in the time step.
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Demand Timeseries Value (ML/d)
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The input template data of demand timeseries from the current farm dam.
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Actual Demand Volume (ML)
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The real water volume is used for the demand in the time step from the current farm dam. Its temporal distribution is determined by Demand Timeseries Value (ML/d) while its value can be different to Demand Timeseries Value (ML/d).
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Diversion Fraction (%)
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The input parameter defines how many percentages of the upstream flow will be directly diverted to the current farm dam.
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Actual Diverted flows (ML/d)
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- Dead Storage Volume (/Dead Storage Proportion) – is the volume of the farm dam stored below the level of the lowest outlet (the minimum supply level). The demand and release requirements cannot access this water, but the natural loss (e.g. evaporation, seepage) in this water still occurs.
Dead Storage Volume can also be inputted as the percentage or proportion of Dam Capacity by ticking the Use Proportion checkbox. The parameter name will also be changed to the Dead Storage Proportion when the Use Proportion checkbox is ticked. The user can click on the %/propor button to swap the type between percentage (%) and proportion.
Note that the values entered from different types (i.e., volume, percentage, and proportion) for the same farm dam cannot be automatically converted until the configuration is saved by clicking on the OK button of the Editor interface.
The Dead Storage Volume can be entered by three types of data sources: (a) from a value, (b) from Data Source, which normally is a time series and (c) from the function.
The range of Dead Storage Volume is between zero and max capacity. Ranges of the percentage and proportion will be from 0 to 100 and 0 to 1 respectively. If the entered values are not within the range, the running error will occur. The user then needs to fix this issue. The example screen of the error message (for entering -1) is shown in Figure 5. “166” in Figure 5 is the name of the associated farm dam.
Figure 5 Running error screen for unsuitable input of Dead Storage Volume
- Bypass Flow - defines the maximum capacity of the flow bypassed from the upstream flow directly to the downstream of the farm dam.
Now Bypass Flow can be entered by four types of data sources: (a) from a value, (b) from Data Source, normally it is a time series, (c) from the function and (d) a Monthly Pattern shown in Figure 6.
Figure 6 The Editor Screen of Select Source for ByPass Flow
The Bypass Flow is designed to be greater or equal to zero. If the entered value is negative, the running error will occur. The user then needs to fix this issue. The example screen of the error message (for entering -2 for Bypass Flow) is shown in Figure 7.
Figure 7 Running error message for unsuitable input of Bypass Flow and Release Volume
- Release Volume - defines the voluntary water release requested from the farm dam. The volume(s) can be entered by three types: (a) from a value, (b) from Data Source, which normally is a time series and (c) from the function.
The Release Volume is also greater or equal to zero. If the entered value is negative, the running error will occur (Figure 7). The user then needs to fix this issue.
- Dam Surface Area Options - provides three options for the dam surface area during the water balance calculation:
- Constant dam surfaces area using ‘Max. Dam Surface Area’ parameter – The entered constant value of Dam Surface Area is used in water balance calculation such as converting rainfall and evaporation from the depth to volume in the farm dam storage.
- Allow dam surface area to vary according to dam volume - The area will be calculated on the basis of the storage volume, default equations and parameters. The storage volume is from the beginning of the time step. The calculated dam surface area at each time step will be used in water balance calculation. Custom Equation Parameters check box is unticked.
- Custom Equation Parameters – This function works only when the option Allow dam surface area to vary according to dam volume is selected and the Custom Equation Parameters check box is ticked. The dam surface area will be calculated based on the storage volume at the beginning of the time step, and the equation of Volume =A*Area^B. Where A and B are input parameters from the Interface. The calculated area at each time step will be used in water balance calculation.
(2) Interstation Flow:
Inflows into a farm dam in this farm dam model come from two alternative sources: (i) overflows from the upstream dam(s) and (ii) the local flow generated by the interstation area between the upstream dams and this dam.
Clinking on the Interstation Flow in the left panel of Figure 4 will display the Interstation flow parameters in the right panel for the configuration (Figure 8). The parameters include Scaling Factor and Reference Timeseries Values/Data Source. The user can select the option Values for the constant value or Data Source for a timeseries defined in Source Data Sources.
The interstation inflow is calculated based on a reference value or time series (i.e., at a flow gauge) that has been scaled down/up. If the scaling factor is 0.8 and the reference timeseries value is 0.25 ML/d, the Actual Interstation Flow (ML) is 0.2 ML/d. The scaling factor reflects (a) the interstation catchment area relative to the reference catchment area; and (b) the nonlinear relationship between the catchment area and flow.
Figure 8 Farm dam editor – Interstation Flow
(3) Seepage
Seepage from the farm dam into the underlying soil can be modelled by defining an exfiltration rate (e.g., mm/d). The water that seeps from the farm dam is lost from the catchment and does not re-enter the system downstream.
Clinking on the Seepage in the left panel of Figure 4 will display the Seepage parameter in the right panel for configuration (Figure 9). The parameters can be configured by the constant value or time series from Data Source.
Figure 9 Farm dam editor – Seepage
(4) Demand
Clinking on the Demand in the left panel of Figure 4 will display the demand parameters in the right panel for configuration (Figure 10). The demand parameters include Demand Factor and Demand Timeseries Values/Data Source. The demand factor can be estimated from the ratio of the average annual demand of the farm dam volume.
In this farm dam model, the demand is not directly using Demand Timeseries. The demand volume is determined by the demand factor and farm dam volume, and its temporal distribution is determined by the Demand Timeseries Values/Data Source.
Figure 10 Farm dam editor – demand
(5) Rainfall
Clinking on the Rainfall in the left panel of Figure 4 will display the rainfall parameters in the right panel (Figure 11). The parameter is the rainfall to the edited farm dam, and it can be configured by constant Values or timeseries data in Data Sources. Its unit is depth such as mm, and Source will convert it to volume by the dam area calculated as the description in section (1) The farm dam information.
Figure 11 Farm dam editor – Rainfall
(6) Evapotranspiration
Clinking on the Evapotranspiration in the left panel of Figure 4 will display the evapotranspiration parameters in the right panel (Figure 12). The parameter is the evapotranspiration from the edited farm dam, and it can be configured by constant Values to timeseries in Data Source. Its unit is depth such as (mm/day) and Source will convert it to volume using the calculated dam area as the description in section (1) The farm dam information.
Figure 12 Farm dam editor – Evapotranspiration
Clicking on the OK button in Figure 4 will save the setup of the farm dam. The Cancel button will discard the entered parameters.
For all Onstream Farm Dams nodes
Source allows inputting, editing, checking, and outputting all parameters of all farm dams together. Tool menu item Edit » Feature Table... can access Feature Table for this functionality (Figure 13). Clicking on the Onstream Farm Dam in the left panel (Figure 13) will display the existing values of all editable parameters for all onstream farm dams in the right panel.
The Feature Table headlines of all parameters are the same as (or similar to) those names described in the above section of For an individual node of Onstream Farm Dam except for seven headlines below:
- Dead Storage Set Using Proportion – This is related to the value of Use Proportion checkbox on the Interface (Figure 4). Its change in the Feature Table will decide which one, Dead Storage Volume or Dead Storage Proportion, will be editable in the Feature Table.
- Dead Storage Volume and Dead Storage Proportion - The definitions of both columns are the same as those in Figure 4. However, although both columns are listed in the Feature Table, only one column in each row can be saved. The edited values in cells of column Dead Storage Proportion will be saved if Dead Storage Set Using Proportion(s) in the same rows are selected. Otherwise, the edited values in the cells of column Dead Storage Volume will be saved. After the Feature Table is saved, the remaining cells in another column (either Dead Storage Volume or Dead Storage Proportion) will be automatically converted from the saved cells by Source.
- Dam Surface Area Calculation – which only has two values for selection: Constant or Variable. The value of Constant indicates the option of Constant dam surfaces area using ‘Max. Dam Surface Area’ parameter (Figure 4) will be used in the water balance calculation. Variable indicates the option Allow dam surface area to vary according to dam volume (Figure 4) will be used in water balance calculation.
- Is Custom Param – shows the value of the check box Custom Equation Parameters (Figure 4). Its value only works when Variable is selected in the column Dam Surface Area Calculation.
- SA-Volume EQN A Factor - the value for A Factor (Figure 4). Its value will be used only when Dam Surface Area Calculation column is Variable and Is Custom Param is ticked.
- SA-Volume EQN B Factor - the value for B Factor (Figure 4). Its value will be used only when Dam Surface Area Calculation column is Variable and Is Custom Param is ticked.
The user can directly edit all parameters from Feature Table.
Figure 13 Farm dam configuration for multiple farm dams through the Feature Table
Recorders of Onstream Farm Dam node
Some recorders for the onstream farm dam in Source are described below to clarify the difference between the similar recorders.
Recorder | Description | Note |
Bypass Flow (ML/d) | The input parameter of the capacity of bypass in the current farm dam. | |
Actual bypassed flows (ML) | The real bypass flows in the time step from the bypassway to the downstream at the current farm dam. It is limited by available upstream flow and Interstation station flow | |
Interstation Flow Reference series (ML/d) | The input Reference data for Interstation Flow. | |
Actual Interstation Flow (ML) | The real Interstation Flow in the time step to the current farm dam, and its value is the product of the Scaling Factor and Interstation Flow Reference series. | |
Evapotranspiration (mm/d) | The input data of evapotranspiration from the current farm dam. | |
Actual Evaporation Volume (ML) | The real evaporation volume in the time step from the current farm dam and its value is based on the dam surface area and inputted Evapotranspiration (mm/d) in the time step. | |
Rainfall (mm/d) | The input data of rainfall to the current farm dam. | |
Actual Rainfall Volume (ML) | The real rainfall volume in the time step to the current farm and its value is based on the dam surface area and inputted rainfall (mm/d) in the time step. | |
SeepageTS (mm/d) | The input data of seepage from the current farm dam. | |
Actual Seepage (ML) | The real seepage volume in the time step from the current farm dam and its value is based on the dam surface area and inputted SeepageTS (mm/d) in the time step. | |
Demand Timeseries Value (ML/d) | The input template data of demand timeseries from the current farm dam. | |
Actual Demand Volume (ML) | The real water volume is used for the demand request from the current farm dam in the time step. Its temporal distribution is determined by Demand Timeseries Value (ML/d) while its value can be different to Demand Timeseries Value (ML/d). | |
Supplied Demand Volume (ML) | The actual released water to meet the requested Actual Demand Volume (ML). It should equal to or less than the Actual Demand Volume (ML). | |
Diversion Fraction (%) | The input parameter defines how many percentages of the upstream flow will be directly diverted to the current farm dam. | |
Actual Diverted flows (ML/d) | The proportioned “upstream” flow, which includes both the upstream flow and interstation inflow, is involved in the water balance calculation for the current farm dam. It is the “upstream” flow scaled down/up by Diversion Fraction (%). | |
Dead Storage Volume (ML) | The input value/time series/function of the Dead Storage Volume (ML). This parameter and the Dead Storage Proportion (%) below are the same parameter in different types. The user only needs to enter one type, and Source will automatically convert one type to another and record both. | |
Dead Storage Proportion (%) | The input value/time series/function of the Dead Storage Volume (ML). This parameter exists as the percentage/proportion of dam capacity. | |
Storage Record (ML) | The simulated storage volume of the farm dam at the end of the time step. This recorder replaces the common recorder of Storage Volume (ML) in the Farm Dam node. | |
Release Volume (ML) | The input parameter for water rerelease requests. | |
Actual Release Volume (ML) | The actual water released to meet the Rerelease Volume requests and its value is limited by the available water. |
Migrate the Source model using the FarmDams plugin across to CORE
The onstream farm dam functionality in Source can be accessed from the plugin of FarmDamsplugin before Version V5.21 or CORE without the Farm Dams plugin after Version V5.21. Only Source projects using the Farm Dams plugin in Version 5.20 can be automatically mitigated to the project with farm darn functionality from CORE. The users need to upgrade their old models (using the Farm Dams plugin) to Source V5.20 with the farm dam plugin first and save it as the upgraded project. The user user then opens the upgraded project in later versions such as late 5.21 without the Farm Dams plugin, and the Source will autumnally migrate the farm dam functionally in the project file from plugin to CORE.
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