Design rainfall estimation for short storm durations using L-moments and generalised least squares regression-application to Australian data

Short duration design rainfall intensity data is a basic input to many water related projects, particularly in urban drainage design. The main problem in deriving short duration design rainfall data is the lack of continuous pluviograph rainfall data. The use of regionalisation techniques is common in design rainfall estimation, which pools data from a large region. This paper presents a regional rainfall estimation method in Australia involving Generalised Least Squares Regression (GLSR) and L moments methods. It has been found that the GLSR and L moments based regional approach is a practical means for estimating short duration design rainfalls and that this provides an efficient statistical framework for assessing uncertainties in design rainfall estimates.