Geophysical Research Letters

Assessing surface water consumption using remotely-sensed groundwater, evapotranspiration, and precipitation

Authors

  • Ray G. Anderson,

    Corresponding author
    1. UC Center for Hydrologic Modeling, University of California, Irvine, California, USA
    2. Now at Water Management Research Unit, USDA Agricultural Research Service, Parlier, California, USA
      Corresponding author: R. G. Anderson, Water Management Research Unit, USDA Agricultural Research Service, 9611 S. Riverbend Ave., Parlier, CA 93648-9757, USA. (ray.anderson@ars.usda.gov)
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  • Min-Hui Lo,

    1. UC Center for Hydrologic Modeling, University of California, Irvine, California, USA
    2. Now at Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan
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  • James S. Famiglietti

    1. UC Center for Hydrologic Modeling, University of California, Irvine, California, USA
    2. Department of Earth System Science, University of California, Irvine, California, USA
    3. Department of Civil and Environmental Engineering, University of California, Irvine, California, USA
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Corresponding author: R. G. Anderson, Water Management Research Unit, USDA Agricultural Research Service, 9611 S. Riverbend Ave., Parlier, CA 93648-9757, USA. (ray.anderson@ars.usda.gov)

Abstract

[1] Estimates of consumptive use of surface water by agriculture are vital for assessing food security, managing water rights, and evaluating anthropogenic impacts on regional hydrology. However, reliable, current, and public data on consumptive use can be difficult to obtain, particularly in international and less developed basins. We combine remotely-sensed precipitation and satellite observations of evapotranspiration and groundwater depletion to estimate surface water consumption by irrigated agriculture in California's Central Valley for the 2004–09 water years. We validated our technique against measured consumption data determined from streamflow observations and water export data in the Central Valley. Mean satellite-derived surface water consumption was 291.0 ± 32.4 mm/year while measured surface water consumption was 308.1 ± 6.5 mm/year. The results show the potential for remotely-sensed hydrologic data to independently observe irrigated agriculture's surface water consumption in contested or unmonitored basins. Improvements in the precision and spatial resolution of satellite precipitation, evapotranspiration and gravimetric groundwater observations are needed to reduce the uncertainty in this method and to allow its use on smaller basins and at shorter time scales.

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