History of development of national guideline Australian Rainfall and Runoff : a case on regional flood estimation

Australia is one of the driest continents on earth, which often suffers from long droughts and also devastating floods. To support water resources development and ongoing management in Australia, a national guideline called Australian Rainfall and Runoff (ARR) is available to engineers, planners and relevant professionals. This paper presents how ARR has been developed over the last 60 years; its first edition was published in 1958, which was followed by its 2nd, 3rd and 4th editions, published in 1977, 1987 and 2019, respectively. Engineers Australia oversees its development and update. In the 4th edition of the ARR, a dedicated research team worked for about ten years to develop and test new methods of design rainfall estimation, flood modelling, urban stormwater management and other rainfall-runoff related topics. The authors of this paper were heavily involved in the preparation of the 4th edition of ARR. There were 24 projects in relation to the preparation of ARR. The first author led Project 5 Regional flood methods of ARR update for eight years, and the second author served as the principal researcher of this project. Both the authors also developed an important statistical model to link short duration and long duration rainfall, which was an important component in the derivation of design rainfalls as a part of ARR Project 1 Development of Intensity Frequency Duration Information across Australia. The first author also contributed significantly to Project 6 Losses in Design Flood Estimation, also his research formed the foundation of the Monte Carlo simulation/joint probability approach to design flood estimation, which has been included as the preferred rainfall-based design flood estimation method in the ARR. This paper also proposes how a national guideline for Bangladesh can be prepared following the example of ARR.