User-generated Statistics

Annual descriptive statistics

Annual descriptive statistics allow you to compare a single result from multiple runs.

To generate annual descriptive statistics, right click on a result in the tree menu and select Statistics » Annual Descriptive Statistics.

Figure 5 shows annual descriptive statistics for a single result:

• The upper left pane shows the overall statistical data;
• The upper right pane allows you to select the relevant run(s); and
• The table at the bottom shows the resulting statistical data on an annual basis.

Figure 5. Annual descriptive statistics

Mass Balance

Results Manager provides a Mass Balance tool to check all of the mass flows entering, remaining in, or leaving the system. It is configurable for time period and for every part of the model that you can choose to enclose in a boundary. 

All individual inputs and outputs for the mass balance are specified by the user from the results of the model run, so before starting a mass balance check, ensure that all required results are recorded. Typical recorded results used in a mass balance check could be:

• All inflow volumes of inflow nodes, 
• storage volume, 
• storage rainfall volume, 
• storage evaporation volume, 
• storage infiltration volume, 
• extracted water from supply points, 
• downstream flow at the lowest point

Each inflow, storage, and outflow need to be added to the appropriate tab (Storage Start, Inflow, Outflows, Storage End).

To calculate mass balance, right click on a result set and select Statistics » New Mass Balance from the contextual menu (Figure 6). A new mass balance statistic will be created and listed under Statistics in the Custom Chart and Statistics pane, and the mass balance tool will be shown in the central workspace (Figure 6), where:

• The lower right pane allows you to select the result set(s) and time period used to calculate the mass balance;

• The upper right pane includes four tabs: Storage Start, Inflow, Outflows, Storage End; which will accept results listed in the upper left pane;

  Note: The Is Grouped checkbox relates to the mass balance report exported from the Results Manager using Export To Excel. If this box is unchecked, the result will be reported as its own separate total, otherwise a single grouped total will be given for each tab.
• The upper left pane lists the results from the selected result sets(s); right click on a result to add it to one of the four tabs in the upper right panel; and
• The lower left pane is the mass balance check, which will calculate the flow from the four tabs in the upper right panel.
  
  

Figure 6. Mass balance

Flood Frequency Analysis

Summary

Flood frequency has often been used in the design of engineering structures such as culverts, bridges and dams. Flood frequency analysis is used to provide a predictive capacity to the
stochastic nature of stream flow. We use the existing, preferably long-term stream flow data to predict the likely magnitude of events of a given return period.

Creation

A flood frequency analysis can be created for a single time series or a custom chart. To a flood frequency analysis for a single time series:

1. right-click on the time series name in the Results Manager tree menu
2. select Statistics » Flood Frequency Analysis

For a custom chart:

1. right-click on the custom chart name in the Results Manager custom charts and statistics pane
2. select Statistics » Flood Frequency Analysis

Details

High/Low Spell Analysis

Summary

Creation

A high spell or low spell analysis can be created for a single time series only. To create one of these analyses:

1. right-click on the time series name in the Results Manager tree menu
2. select Statistics » High Spell Analysis or Statistics » Low Spell Analysis

Details