Irrigation in California's Central Valley strengthens the southwestern U.S. water cycle
Journal
Geophysical Research Letters
Journal Volume
40
Journal Issue
2
Pages
301-306
Date Issued
2013
Author(s)
Famiglietti, J.S.
Abstract
Characterizing climatological and hydrological responses to agricultural irrigation continues to be an important challenge to understanding the full impact of water management on the Earth's environment and hydrological cycle. In this study, we use a global climate model, combined with realistic estimates of regional agricultural water use, to simulate the local and remote impacts of irrigation in California's Central Valley. We demonstrate a clear mechanism that the resulting increase in evapotranspiration and water vapor export significantly impacts the atmospheric circulation in the southwestern United States, including strengthening the regional hydrological cycle. We also identify that irrigation in the Central Valley initiates a previously unknown, anthropogenic loop in the regional hydrological cycle, in which summer precipitation is increased by 15%, causing a corresponding increase in Colorado River streamflow of ∼30%. Ultimately, some of this additional streamflow is returned to California via managed diversions through the Colorado River aqueduct and the All-American Canal. © 2013. American Geophysical Union. All Rights Reserved.
Other Subjects
Agricultural irrigation; Agricultural water use; Atmospheric circulation; Colorado River; Global climate model; Hydrological cycles; Hydrological response; Summer precipitation; Climatology; Hydraulic structures; Landforms; Stream flow; Water management; Water supply; Irrigation; climate modeling; evapotranspiration; global climate; hydrological cycle; irrigation system; precipitation (climatology); streamflow; water management; water use; water vapor; California; Central Valley [California]; United States
Type
journal article