Selection of Events

The events that can be selected can be categorised as either Standard or Custom Events.

 

Standard Events

Standard events include Point Temporal Patterns, Areal Temporal Patterns and ARR1987 Temporal Patterns. You can add Point, Areal (assuming Areal TPs are loaded) and ARR1987 events at the same time and compare the results.

Standard Events (63.2% - 1% AEP), Very Frequent or Rare Events can be accessed via the checkboxes to the right.

Typical event / temporal pattern classification configurations are highlighted in light blue and can be selected automatically via right click menu.

The Prefix field allows some text to be added the start of all event labels. This can be useful when comparing results from multiple projects which can be done by loading multiple run lists.

 

Point TP Events

PointTP

PointFrequentTP

PointRareTP

 

Areal TP Events

ArealTP_2

 

ARR1987 TP Events

Select the recurrence interval and TP Zone combinations to be modelled. ARR1987 storm use the following parameters:

IFD values based on an *ARR87* IFD Location.
Pervious loss rates (IL/CL) as per the ARR 87 Pervious Losses box in the settings tab
Impervious Losses as per the Impervious Losses (ARR2016 and ARR1987) box in the settings tab
ARF (depth-area ratios) based on Figure 1.6 ARR 87 approximated by polynomial.
Temporal Patterns from ARR 87 Vol 2 Table 3.2

 

ARR1987TP

 

Durations

You can customise which durations are to be modelled in the Durations tab. Individual durations can be checked or unchecked and the right click menu can automatically check or uncheck durations longer or shorter than a user specified value.

Durations

 

Custom Events

Custom Events are typically used for sensitivity analysis for partial area, rainfall increase, initial loss uncertainty and climate change. They can also be used to apply the growth curves for events rarer than 1% AEP and durations < 24 hours. Custom Events can be renamed to suit the user's preferences by appending $Name$ to the end of the custom event (that is, the new name book-ended by the $ character. For example, the estimation of rarer than 1% AEP events using the growth curves in Table 8.3.2 (Section 3.6.3 Book 8) can be accommodated using the following Rainfall Increase custom events and renamed as follows:

RInc_1% AEP_14.0_rare$200YrARI$
RInc_1% AEP_34.4_rare$500YrARI$
RInc_1% AEP_51.3_rare$1000YrARI$
RInc_1% AEP_69.8_rare$2000YrARI$

 

In the Custom Event format, the event description is always the 2nd field (underscore delimiter). To access frequent or rare IFD events, simply use their event descriptors such as '1 in 1000' or '12EY'. To access ARR 1987 events, use their descriptors such as '100 Yr'.

More information on the types of custom events available is shown below.

 

Partial Area Checks

Partial Area Checks (PAC) are useful to investigate the effects of differing ARFs related to different areas of interest. For example, if your entire rainfall runoff model catchment is 100 km2 (and this was entered in the Catchment Details panel) and yet you are also interested in the results of a subcatchment in your model that has a catchment of 50 km2, then you may consider including a 50 km2 PAC. This will allow you to quantify the difference in runoff due to the change in ARF. In this example, total rainfall depth would be about 4% higher for the 1% AEP, 24hr event with ARR 2016.

A PAC for a point temporal pattern example is: PAC_1% AEP_50_rare which would indicate a PAC with ARFs based on 50 km2 area for the rare temporal patterns.
A PAC for a areal temporal pattern example is: PAC_1% AEP_50_100 which would indicate a PAC with ARFs based on 50 km2 area for the 100km2 reference area temporal pattern.
A PAC for a point temporal pattern example is: PAC_100 Yr_50_ARR87Z1 which would indicate a PAC with ARFs based on 50 km2  for the 100 Yr event with ARR 1987 temporal patterns for Zone 1.

 

Rainfall Increase Sensitivity Analysis

To enter a hard-coded rainfall increase event, enter a code of the form RInc_AEP_Increase/(-)Decrease(%)_temporal pattern classification (eg., rare for point temporal patterns or reference area for areal temporal patterns.

A point temporal pattern example is: RInc_1% AEP_20_rare which would indicate a 20% rainfall increase for the 1% AEP for the rare temporal patterns.
An areal temporal pattern example is: RInc_1% AEP_20_100 which would indicate a 20% rainfall increase for the 1% AEP for the 100km2 reference area temporal pattern.
An ARR 87 example is: RInc_100 Yr_20_ARR87Z1 which would indicate a 20% rainfall increase for the 100 Yr event with ARR 1987 temporal patterns for Zone 1.

 

Pervious Initial Loss Sensitivity Analysis

To enter an adjustment to the net previous initial loss rate, enter a code of the form ILInc_AEP_Increase/(-)Decrease(%)_temporal pattern classification (eg., rare for point temporal patterns or reference area for areal temporal patterns.

A point temporal pattern example is: ILInc_1% AEP_-20_rare which would indicate a 20% initial loss decrease for the 1% AEP for the rare temporal patterns.
An areal temporal pattern example is: ILInc_1% AEP_-20_100 which would indicate a 20% initial loss decrease for the 1% AEP for the 100km2 reference area temporal pattern.
An ARR 87 example is: ILInc_100 Yr_-20_ARR87Z1 which would indicate a 20% initial loss decrease for the 100 Yr event with ARR 1987 temporal patterns for Zone 1.

 

Interim Climate Change Events

To enter an Interim Climate Change (ICC) based event, you can enter similar codes that reference the Year and RCP version in order to lookup the percentage rainfall increase.

A point temporal pattern example is: ICC_1% AEP_2090_RCP 8.5_rare which would indicate a rainfall increase for the 1% AEP for the rare temporal patterns based on the 2090 RCP 8.5 predictions.
An areal temporal pattern example is: ICC_1% AEP_2090_RCP 8.5_r100 which would indicate a rainfall increase for the 1% AEP for the 100km2 reference area temporal patterns based on the 2090 RCP 8.5 predictions.
An ARR 87 example is: ICC_100 Yr_2090_RCP 8.5_ARR87Z1 which would indicate a rainfall increase for the 100 Yr event with ARR 1987 temporal patterns for Zone 1 based on the 2090 RCP 8.5 predictions.

 

These codes can also be developed by right clicking on the relevant cell in the Interim Climate Change Factors grid.

customevent

 

Once the appropriate events have been selected, the storms can be created.