Francina Dominguez1, Sandy Dall'erba2, Shuyi Huang3, Andre Avelino2, Ali Mehran4, Huancui Hu1, Arthur Schmidt3, Lawrence Schick5, and Dennis Lettenmaier4
1Department of Atmospheric Sciences, University of
Illinois at Urbana-Champaign, Urbana, Illinois, USA
2Department of Agricultural and Consumer Economics,
University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
3Department of Civil and Environmental Engineering,
University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
4Department of Geography, University of California
Los Angeles, Los Angeles, California, USA
5US Army
Corps of Engineers, Seattle District, USA
Received: 16 Jun 2017 – Discussion started: 26 Jun 2017
Revised: 24 Oct 2017 – Accepted: 13 Jan 2018 – Published: 16 Mar 2018
Abstract. Atmospheric rivers (ARs) account for more than 75 % of heavy precipitation events and nearly all of the extreme flooding events along the Olympic Mountains and western Cascade Mountains of western Washington state. In a warmer climate, ARs in this region are projected to become more frequent and intense, primarily due to increases in atmospheric water vapor. However, it is unclear how the changes in water vapor transport will affect regional flooding and associated economic impacts. In this work we present an integrated modeling system to quantify the atmospheric–hydrologic–hydraulic and economic impacts of the December 2007 AR event that impacted the Chehalis River basin in western Washington. We use the modeling system to project impacts under a hypothetical scenario in which the same December 2007 event occurs in a warmer climate. This method allows us to incorporate different types of uncertainty, including (a) alternative future radiative forcings, (b) different responses of the climate system to future radiative forcings and (c) different responses of the surface hydrologic system. In the warming scenario, AR integrated vapor transport increases; however, these changes do not translate into generalized increases in precipitation throughout the basin. The changes in precipitation translate into spatially heterogeneous changes in sub-basin runoff and increased streamflow along the entire Chehalis main stem. Economic losses due to stock damages increase moderately, but losses in terms of business interruption are significant. Our integrated modeling tool provides communities in the Chehalis region with a range of possible future physical and economic impacts associated with AR flooding.
Citation:
Dominguez, F., Dall'erba, S., Huang, S., Avelino, A., Mehran, A., Hu, H., Schmidt, A., Schick, L., and Lettenmaier, D.: Tracking an atmospheric river in a warmer climate: from water vapor to economic impacts, Earth Syst. Dynam., 9, 249-266, https://doi.org/10.5194/esd-9-249-2018, 2018.