Addressing embedded bursts in design storms for flood hydrology

Abstract

In design flood hydrology, storm depths for rare events are characterised using methods such as Intensity Frequency Duration (IFD) curves. These approaches are concerned with the main part of a storm, referred to as the “burst”. The burst represents the period within the storm that has the smallest probability of occurrence. When used in runoff-routing models, burst depths are disaggregated using temporal patterns. However, this process can result in “embedded bursts” occurring in the hyetograph. This is where a sub-period of rainfall within a burst has a smaller Annual Exceedance Probability (AEP) than that of the burst being considered. This paper demonstrates the extent to which embedded ..