H143-0002
Assessing Vulnerability and Adaptive Management Under Climate Change Scenarios: Lessons from California’s Largest Reservoir
Monday, 14 December 2020
Poster
Mike Sierks, Scripps Institution of Oceanography, La Jolla, CA, United States, Michael D Dettinger, Scripps Institution of Oceanography, Center for Western Weather and Water Extremes, La Jolla, CA, United States, William Chapman, Scripps Institution of Oceanography, Center for Western Weather and Water Extremes (CW3E), La Jolla, CA, United States and F Martin Ralph, University of California, San Diego, San Diego, CA, United States
Abstract:
With the arrival of increasing droughts and floods, declining snowpacks, increasing temperatures, and increasing evapotranspiration demands, the ways in which the American West has managed water for the past 75 years increasingly appear to be insufficient in sustaining projected demand. There is a growing body of research focused on addressing not just the hydrometeorological changes in response to global warming, but how these changes will impact the management of water. However, because of the interconnected, complicated, and highly constrained nature of California’s water resources infrastructure, climate change modelling efforts are often restricted to existing operations. Apart from a few exceptions, little work has been done to investigate the impacts of climate change mitigation/adaptation measures on individual reservoirs or adaptation strategies. Additionally, it is unclear which variables, both hydrometeorological and operational, dictate the sensitivity of one reservoir relative to another in response to global warming, which is important as individual river basins, watersheds, and reservoir drainage areas will not be impacted uniformly.
This research uses California’s largest reservoir, Lake Shasta, situated in a low-elevation rain-and-snow dominated basin, as a case study to: 1) investigate potential impacts of climate change on susceptible reservoirs from both a water supply and flood-risk mitigation perspective, 2) distinguish key variables (physical and/or hydrometeorological) which govern Shasta’s vulnerability to climate change relative to several other reservoirs in California, and 3) evaluate the efficacy of various climate change adaptation strategies (e.g. increased storage, adjusted operating procedures) in mitigating impacts on reservoir performance.
To that end, we develop a statistical model of the Shasta reservoir to simulate historical reservoir operations at a daily resolution. This model is then used to explore future reservoir performance, from both water supply and flood-risk mitigation perspectives, through the use of statistically downscaled CMIP5 data.
