We frequently use design storms to evaluate existing and proposed stormwater management systems. Design storms vary by geographic location and are typically designated by duration and frequency such as the 10year - 24hour storm. We are encouraged to consult local regulations and design manuals to obtain the appropriate design storms for their systems.
It is a common practice to evaluate the performance of systems against multiple design storms. The Global Storms tool in the user interface allows us to analyze several storms simultaneously and to compare results on a single graph.
Creating a design storm event has two steps involved:
Rainfall intensities are provided by the Bureau of Meteorology (BOM) for different durations and recurrence intervals for all locations around Australia based on a 2 km2 GRID.
The rainfall intensities are multiplied by the temporal patterns to give design storms. Twelve temporal zones are used to describe the rainfall storm patterns across Australia based on Australian Rainfall and Runoff Guidelines 2016 (ARR16).
Temporal Pattern Regions – Source: ARR 2016 Book 2 Chapter 5
Each zone provides 10 storm patterns per standard duration for each recurrence interval range as described in ARR16. The 10 patterns are referred to as an ensemble.
Temporal Pattern Ranges – Source: ARR 2016 Book 2 Chapter 5
This example demonstrates adding design storm ensembles for Brisbane, Queensland, Australia for the 1% AEP 1, 2 and 3 hour durations.
Use the scroll wheel on the mouse to zoom and pan to find the Brisbane Airport. Click the Airport to populate the Latitude (-27.381) and Longitude (153.123) of the desired location. Alternatively, you could type these in manually. Select Download. The Data Files status should change to ‘Downloaded’ once successful. Click OK.