Australian rainfall and runoff - the interim climate change guideline

Abstract

There is now widespread acceptance that human activities are contributing to observed climate change. Human-induced climate change has the potential to alter the prevalence and severity of rainfall extremes, storm surge and floods. Recognition of the risks associated with climate change is required for better planning of new infrastructure and mitigating potential damage to existing infrastructure. Policy makers, planners and the designers of hydraulic structures will need to base their decisions on up-to-date information from reliable sources. This paper describes the Interim Guideline for Climate Change for Australian Rainfall and Runoff (ARR) which outlines an approach to address the risks from climate change in projects and decisions that involve estimation of design flood characteristics. The Interim Guideline draws on the most recent climate science, particularly the release of the IPCC Fifth Assessment Report in September 2013 as well as the new climate change projections for Australia. For consistency with the new Intensity-Frequency-Duration design rainfall estimates for ARR, the Interim Guideline is intended to be applied to the key system design event (i.e., the design standard for the structure or infrastructure). It is applicable for current-day rainfall intensities within the range of probability of one exceedance per year and annual exceedance probabilities from 50% to 1%.