Hydroclimatically-Defined Mixed Distributions in Partial Duration Flood Series

The possibility of mixed distributions in flood series is widely recognized and attempts to separate records into homogeneous subsets have been encouraged. climatic is often proposed as a source of mixed distributions, but the separation of flood records into climatic subgroubs has tended to focus on seasonal divisions or a partitioning of the flood series into rainfall and snowmelt-generated events. In this study, a detailed Hydroclimatic analysis is used to categorize floods on the basis of the synoptic weather patterns which produced them. This procedure represents the first attempt to the classify flood-generating mechanism responsible for each event. The technique identifies mixed distributions by using physically-based information that is independent of the runoff series, rather by defining subpopulations on the basis of the shape of the parent distribution itself.