Sensitivity of Australian roof drainage structures to design rainfall variability and climatic change

Abstract

The main design determinant for small catchment hydraulic structures is rainfall intensity. Localised relationships between rainfall intensity, frequency and duration (IFD) are used to design each structure to a specified level of performance. However, limitations in rainfall observations introduce uncertainty in IFD values. Further, this uncertainty is compounded by changes in climatic conditions via anthropogenic forcing. Whether this is a cause for concern depends on the structure's sensitivity to deviations away from design rainfall values. Here, we investigate the ability of roof drainage systems to accommodate deviations in design rainfall. We assess the sensitivity of box gutter overf..