Models, Managers, and eMissions: hydrologic climate change planning under a flood of scenarios

Oriana Chegwidden

Dept. of Civil and Environmental Engineering, University of Washington

Tuesday, Jul 28, 2020, 2:00 pm
Webinar

Abstract

Whether at the scale of a small watershed or a large multinational basin, it has become common practice for water managers to use ensembles of projections to plan for hydrologic change. Better understanding these ensembles can help improve the design of future hydrologic modeling studies. In this presentation I will briefly showcase three uses of hydroclimate ensembles to support water resource planning efforts. I will first present a large ensemble of hydrologic climate change projections for the Columbia River basin within the hydroclimatically diverse Pacific Northwestern United States and Canada (PNW). I will show how methodological decisions in the modeling process variously affect the projections of change depending on hydroclimatic regime and metric of interest. I will then delve deeper into the PNW to examine projected changes in floods, determining how dominant flood generating processes will evolve under climate change. I also calculate first-order sensitivities of high flows to changes in climate. Finally, I will apply some lessons learned from the first two studies, conducted within the transboundary Columbia River basin, to transboundary rivers around the world. I will present a study identifying hot spots of changes in water availability and hydropolitical risk for over 80 rivers (esp. transboundary rivers) around the world as projected by results from the Coupled Model Intercomparison Project Phase 6. Throughout the talk I will emphasize how the research’s findings can contribute to improved hydroclimate impacts assessments.