DRAINS Refresher and ARR 2019 Workshops
This workshop provides demonstrations and exercises using new parts of DRAINS that operate with these procedures from Australian Rainfall and Runoff, 2019:
- 2016 Intensity-Frequency-Duration data from the Bureau of Meteorology,
- Ensembles of temporal patterns from the ARR Data Hub,
- Climate change adjustments,
- the ARR 2019 Initial loss – continuing loss urban hydrological model,
- design for median results instead of ‘worst case’ results.
It also looks at changes to design rainfall data and patterns between 1987 and 2019, and different results obtained with hydrological models such as the ARR 2019 IL-CL model, Horton ILSAX, extended rational method (ERM), the rational method, and models such as RORB, RAFTS and WBNM. Sensitivity studies will be explained and demonstrated.
The new methods produce more voluminous and complex results than previous procedures, and interpretation is more difficult. Some advice from ARR 2019 is still incomplete, such as the application of pre-burst or initial losses and the specification of equivalent impervious areas in the IL-CL model. Designers and Council officers will need to work out appropriate assumptions and rules. To aid this process, the workshop includes discussion sections, where questions like these will be considered:
- Can we stay with 1987 methods?
- How can differences in model results be assessed?
- What are the most important design issues?
- What rules should councils and drainage authorities apply?
The workshop is intended for persons who are familiar with DRAINS. It will serve as a refresher, but we will not be covering the basic operations of DRAINS. These are presented in the Introduction to DRAINS Workshop, which will also cover ARR 2019 changes.