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ARS Home » Midwest Area » Columbia, Missouri » Cropping Systems and Water Quality Research » Research » Publications at this Location » Publication #349313

Research Project: Long-term Management of Water Resources in the Central Mississippi River Basin

Location: Cropping Systems and Water Quality Research

Title: Uncertainty of water budget closure across the Long-Term Agroecosystems Research network

item Baffaut, Claire
item BROOKS, ERIN - University Of Idaho
item Pierson Jr, Frederick
item Demaria, Eleonora
item Goodrich, David - Dave
item Elias, Emile
item Hoover, David
item Liebig, Mark
item Moriasi, Daniel
item Harmel, Daren
item Smith, Douglas
item OKALEBO, JANE - University Of Nebraska
item Moorman, Thomas
item Witthaus, Lindsey
item HAMILTON, STEPHEN - Michigan State University
item Bosch, David - Dave
item King, Kevin
item SAHA, AMARTYA - Archbold Biological Station
item Buda, Anthony
item McCarty, Gregory

Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 1/14/2018
Publication Date: 7/29/2018
Citation: Baffaut, C., Brooks, E., Pierson Jr, F.B., Demaria, E.M., Goodrich, D.C., Elias, E.H., Hoover, D.L., Liebig, M.A., Moriasi, D.N., Harmel, R.D., Smith, D.R., Okalebo, J.A., Moorman, T.B., Yasarer, L.M., Hamilton, S.K., Bosch, D.D., King, K.W., Saha, A.K., Buda, A.R., Mccarty, G.W. 2018. Uncertainty of water budget closure across the Long-Term Agroecosystems Research network. ASABE Annual International Meeting, July 29-Auguast 1, 2018, Detroit, Michigan. Paper #1800938.

Interpretive Summary:

Technical Abstract: Quantification of the various components of the hydrologic budget at a site (precipitation, evaporation, runoff,…) gives important indications about major and minor hydrologic processes controlling field and watershed scale response. The objectives of this study were to: 1) develop hydrologic budgets for watersheds (> 400 ha) and/or fields (< 100 ha) at the 18 USDA Long-Term Agroecosystems Research (LTAR) network sites using measured data, model estimates, and/or relevant published literature values, for periods ranging from 2 to 50 years, and 2) quantify the uncertainty of these fluxes and the uncertainty with which the water balance can be closed. Uncertainty of each component was quantified based on measurement or estimation techniques, published literature, and years of data available. Propagation of uncertainties utilized the quadrature formula. Closure uncertainties ranged from 11% to 62%. Factors that contributed to small (<20%) water balance closure uncertainties included humid environments, long data sets (>10years), measurement or estimation of each water budget component, and filling-in of missing data. Errors were greater (>30%) in semi-arid environments and when components were not fully measured or estimated over a long period. At some sites, model estimates of non-measured variables helped close the water balance and reduce the uncertainty of the water balance closure. Detection and understanding of changes in the hydrologic budget at a site requires long measurement periods and appropriate data post-processing methods.