A key challenge for societal adaptation to present and future climate is to reliably characterize the expected frequency and intensity of extreme precipitation events

and related quantities, such as extreme snow and wind loading of structures. This information is required for all types of infrastructure that are exposed to the elements, ranging from typical family dwellings and the streets and storm water handling systems that serve them to mega-projects such as Site-C. This talk will first describe observed and projected changes in precipitation extremes from a global perspective. The broad evidence at these scales indicates that human influence on the climate system has intensified precipitation extremes in a manner that is consistent with warming, and that this will continue, supporting the notion that “stationarity is dead”. Nevertheless, the evidence is not yet very evident on local and regional scales, and this, coupled with large variability and limited observational records, makes the estimation of changes in the characteristics of extremes in the context of nonstationarity very difficult. This is true for both the so-called “intensity-duration-frequency” (IDF) curves that are used extensively in engineering practice and for engineering based concepts such as “probably maximum precipitation” (PMP) that are often used for reservoir design.  The remainder of the talk will therefore discuss some of the challenges associated with improving the robustness of IDF curve estimates, focusing on the identification of scaling relationships with other climate variables, and with assessing the uncertainty of PMP estimates.

The Natural Resources & Environmental Studies Institute (NRESi) at UNBC hosts a weekly lecture series at the Prince George campus. Anyone from the university or wider community with interest in the topic area is welcome to attend. Presentations are also made available to remote participants through Livestream. More information will be posted about these presentations as it becomes available.

Past NRESi colloquium presentations and special lectures can be viewed on our video archive, available here