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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Hydrology and Remote Sensing Laboratory » Research » Publications at this Location » Publication #386045
Research Project: Integrating Remote Sensing, Measurements and Modeling for Multi-Scale Assessment of Water Availability, Use, and Quality in Agroecosystems

Location: Hydrology and Remote Sensing Laboratory

Title: Can we use the water budget to infer upland catchment behavior? The role of dataset error estimation and interbasin groundwater flow

Author
item GORDEN, B. - University Of Nevada
item Crow, Wade
item KONINGS, A. - Stanford University
item DRALLE, D. - Us Forest Service (FS)
item HARPOLD, A. - University Of Nevada

Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2022
Publication Date: 9/12/2022
Citation: Gorden, B.L., Crow, W.T., Konings, A.G., Dralle, D.N., Harpold, A.A. 2022. Can we use the water budget to infer upland catchment behavior? The role of dataset error estimation and interbasin groundwater flow. Water Resources Research. 58(9):e2021WR030966. https://doi.org/10.1029/2021WR030966.
DOI: https://doi.org/10.1029/2021WR030966

Interpretive Summary: A large fraction of irrigation agriculture in the United States is supplied with water yield from higher-elevation, snow-dominated catchments. As a result, hydrologists and water resource managers need appropriate tools to anticipate future changes in water supply from these areas. Unfortunately, the application of these tools is often hampered by the presence of significant random errors in our best-available estimates of precipitation and streamflow. This paper clarifies how our ability to forecast streamflow changes in upland basins is affected by these errors and tests mathematical approaches to limit their impact. The results of this analysis will eventually be used to improve our ability to track seasonal and inter-annual variations in streamflow from upload basins and improve our ability to effectively manage water resources in the face of this variability.

Technical Abstract: Assessments of higher elevation (upland) catchment behavior in the Budyko hypothesis often use different strategies inter-changeably to evaluate the evaporative index (i.e., evapotranspiration (ET)/precipitation (P)), interchangeably. However, common strategies make different assumptions about whether storage changes ('S), unknown fluxes (e.g., groundwater), and product error can be ignored (a closed water budget - ET_CWB) or not (an open water budget - ET_OWB). Few studies quantify how these strategies interact with underlying water budget closure to influence inferred catchment behavior. Here, we assess this interaction in light of expanded efforts to use the Budyko hypothesis to validate global models and anticipate climate change impacts to water supply. Using three products in upland catchments throughout the United States (US), we show a deficit in water budget closure in the western US consistent with underpredicted P that produces significant differences between ET_CWB and ET_OWB. Here, such a long-term water budget deficit interacts with ET_CWB to yield systematic plotting below the Budyko curve, inflating streamflow sensitivity to snow fraction by up to 15 times and dampening inferred streamflow elasticity to P by up to 25% when compared to the ET_OWB. Filtering random error in P and ET products through triple collocation-based merging improves closure in 64 of 114 catchments—four times better than the best gridded product; however, improvements do not produce widespread agreement between ET_CWB and ET_OWB. Thus, under current observational limitations, differences in ET_CWB and ET_OWB interact with long-term water budget deficit to systematically influence catchment plotting in the Budyko space with significant implications for water supply prediction in upland catchments.