Rivers and Climate Change in the Greater Yellowstone Ecosystem

Our Research

We study how climatic variability changes river form and function. We use the geologic record to understand how previous periods of drought and climate change altered riparian ecosystems. Our research also explores how recent floods and droughts are currently impacting Yellowstone rivers. Documentation and analysis of the channel dynamics and geomorphic history are essential for understanding how climate change is and will continue to alter stream behavior. 

June 2022 Flood

From June 10–13, 2022 an atmospheric river delivered 2.5–10 cm of rain in and around northern Yellowstone National Park. The rain melted 5–13 cm of snow water equivalent resulting in a total of 7.6–23 cm of water delivered to the landscape. Peak discharges on at least four stream gages on the Yellowstone River and its tributaries exceeded the flood of record and caused extensive damage to park infrastructure.. Due to climate change, they are likely to be more common in the greater Yellowstone ecosystem and throughout much of western North America . Considerable uncertainty exists, however, in terms of how climate change will alter temporal patterns and intensity of precipitation, how such changes will alter hillslope processes (e.g., landslides and other erosion) and flooding, and how river systems will respond. Our Research is focused on documenting the effects of the June 2022 flood and how climate change is altering river dynamics.

Yellowstone Extreme Floods Rapid Response Team (YEFRRT)

Climatic Influence on Streams

In Yellowstone, periods of increased drought (yellow line) are correlated with increased forest fire activity (readline) and a decrease in beaver activity on small streams (blue line). Due to climate change, periods of drought severe drought will increase in frequency. In the images below, there was an active beaver dam on this small tributary of Elk Creek in the 1920s. The site was abandoned by the 1950s and during the early 2000s drought, the stream was ephemeral and would not support beaver. 

The Impacts of Climate Change

In the future, humans will very likely influence beaver and stream habitats in the GYE through anthropogenic warming of climate as well. In the 1920s, the 10-yr average PDSI value was in the 86th per- centile of values for the past 2000 years, highlighting the unusually wet conditions that produced high streamflows, even in a millennial context. In contrast, future streamflows in the GYE are likely to fall to opposite extremes at times com- pared with the 1920s, as regional models predict an increased probability of severe and prolonged drought in the coming cen- tury. Thus, it is probable that a greater number of small streams will become ephemeral and unsuitable for beaver colonization, as has already been observed in northern Yellowstone, producing a landscape-scale reduction in riparian habitat.