Partial Series Analysis of High Flows in Canadian Rivers

The study of discharge records provides important information about both streamflow and hydrometeorologic variables. One of the principal topics of interest in streamflow analysis is that of high flows. Not only are these potentially most damaging, but also in the highly seasonal hydrologic regime of Canada, they represent the movement of considerable proportions of the annual discharge. Partial duration series includes all flow events above some arbitrary level of interest in the high flow analysis, and this is a major reason that it is preferable to the annual series.Existing stochastic models of partial series are applied to the historic records of sixteen rivers selected to be representative of the major physiographic and climatic regions of Canada. The models are found to be applicable in all cases and to provide valuable information concerning the return periods of magnitudes, durations, timing and number of high flow events. Easily estimated parameter values used to operationalize the distributions reflect the changing physical settings of the sample rivers thereby providing a statistical summary of high flow regime and its spatial variability.