Relationship Between Wildfires and Flooding in the Western United States
Faculty Mentor
Richard Orndorff
Document Type
Poster
Start Date
10-5-2023 11:15 AM
End Date
10-5-2023 1:00 PM
Location
PUB NCR
Department
Geology
Abstract
As wildfires have increased in magnitude and frequency across the western United States, flood frequency and magnitude have also increased. In forest environments, the soil is typically extremely absorbent, so it is useful for flood protection. But after a high intensity fire burns through a wooded area, it leaves behind charred, hardened soil that is unable to absorb the same quantity of water, creating prime conditions for flooding and debris flows. According to the Proceedings of the National Academy of Sciences (PNAS), in the Western U.S. annual forest fire area has increased by more than 1,100% from 1984 to 2020 (Williams et al., 2022). Areas where over 20% of forest area burned in a year, local streamflow increased by an average of 30% over a period of 6 years. While increased streamflow may seem helpful for increasing water supply, it can actually be destructive according to Park Williams (one of the co-authors in the PNAS study) in an article in Smart Water Magazine. With such extreme increases, reservoirs, dams, and other infrastructure can be overwhelmed, leading to an increased risk of catastrophic floods and mudflows. I will discuss these and other issues related to the connection between wildfires and flooding.
Recommended Citation
Smith, Annika, "Relationship Between Wildfires and Flooding in the Western United States" (2023). 2023 Symposium. 16.
https://dc.ewu.edu/srcw_2023/res_2023/p2_2023/16
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Relationship Between Wildfires and Flooding in the Western United States
PUB NCR
As wildfires have increased in magnitude and frequency across the western United States, flood frequency and magnitude have also increased. In forest environments, the soil is typically extremely absorbent, so it is useful for flood protection. But after a high intensity fire burns through a wooded area, it leaves behind charred, hardened soil that is unable to absorb the same quantity of water, creating prime conditions for flooding and debris flows. According to the Proceedings of the National Academy of Sciences (PNAS), in the Western U.S. annual forest fire area has increased by more than 1,100% from 1984 to 2020 (Williams et al., 2022). Areas where over 20% of forest area burned in a year, local streamflow increased by an average of 30% over a period of 6 years. While increased streamflow may seem helpful for increasing water supply, it can actually be destructive according to Park Williams (one of the co-authors in the PNAS study) in an article in Smart Water Magazine. With such extreme increases, reservoirs, dams, and other infrastructure can be overwhelmed, leading to an increased risk of catastrophic floods and mudflows. I will discuss these and other issues related to the connection between wildfires and flooding.
