Application of the vineyard data assimilation (VIDA) system to vineyard root-zone soil moisture monitoring in the California Central Valley

Authors: CHEN, FAN - Science Systems And Applications, Inc; LEI, FANGNI - Mississippi State University; Knipper, Kyle; Gao, Feng; McKee, Lynn; ALSINA, MARIA MAR - E & J Gallo Winery; Alfieri, Joseph; Anderson, Martha; BAMBACH, NICOLAS - University Of California, Davis; CASTRO, SEBASTIAN - University Of California, Davis; McElrone, Andrew; ALSTAD, KARRIN - University Of California, Davis; DOKOOZLIAN, NICK - E & J Gallo Winery; GREIFENDER, FELIX - Eurac Research; Kustas, William - Bill; NOTARNICOLA, CLAUDIA - Eurac Research; AGAM, NURIT - Ben Gurion University Of Negev; Prueger, John; HIPPS, LAWRENCE - Utah State University; Crow, Wade

Submitted to: Irrigation Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/18/2022
Publication Date: 4/23/2022
Citation: Chen, F., Lei, F., Knipper, K.R., Gao, F.N., McKee, L.G., Alsina, M., Alfieri, J.G., Anderson, M.C., Bambach, N., Castro, S.J., McElrone, A.J., Alstad, K., Dokoozlian, N., Greifender, F., Kustas, W.P., Notarnicola, C., Agam, N., Prueger, J.H., Hipps, L., Crow, W.T. 2022. Application of the vineyard data assimilation (VIDA) system to vineyard root-zone soil moisture monitoring in the California Central Valley. Irrigation Science. https://doi.org/10.1007/s00271-022-00789-9.
DOI: https://doi.org/10.1007/s00271-022-00789-9

Interpretive Summary: Root-zone soil moisture information is key to irrigation management strategy. However, understanding and predicting patterns in root-zone soil moisture is difficult as it can vary considerably over very small areas. This difficultly is exacerbated when attempting to understand and predict these patterns in real-time for irrigation management strategy. This paper discusses the prospects of addressing these challenges by creating and testing a model designed to predict root-zone soil moisture in vineyards located in California. The model is based on satellite information and a modeling technique known as data assimilation. Model results show that it is capable of producing the general trends in root-zone soil moisture when compared to soil moisture sensors installed throughout the vineyard under study. It also shows that the modeling effort improves the temporal estimates of root zone soil moisture. However, shortcomings still exists; mainly the disconnect between certain satellite products and soil moisture that can occur during specific times of year and produce soil moisture estimates that stray from observations. Potential solutions to this issue are also discussed.

Technical Abstract: Efforts to apply gridded root-zone soil moisture (RZSM) products for irrigation decision-support in vineyards are currently hampered by the difficulty of obtaining RZSM products that meet required accuracy, resolution, and data latency requirements. In particular, the operational application of soil water balance modelling is complicated by the difficulty of obtaining accurate irrigation inputs and representing complex sub-surface water-flow processes within vineyards. Here, we discuss prospects for addressing these shortcomings using the Vineyard Data Assimilation (VIDA) system based on the assimilation of high-resolution (30-m) soil moisture information obtained from synthetic aperture radar and thermal-infrared (TIR) remote sensing into a one-dimensional soil water balance model. The VIDA system is tested retrospectively (2017-2020) for two vineyard sites in the California Central Valley that have been instrumented as part of the Grape Remote sensing Atmospheric Profile and Evapotranspiration eXperiment (GRAPEX). Results demonstrate that VIDA can generally capture daily temporal variations in RZSM for vertical depths of 30-60 cm beneath the vine row, and the assimilation of remote sensing products is shown to produce modest improvement in the temporal accuracy of VIDA RZSM estimates. However, results also reveal shortcomings in the ability of VIDA to correct biases in assumed irrigation applications—particularly during well-watered portions of the growing season when TIR-based evapotranspiration observations are not moisture limited and ,therefore, decoupled from RZSM. Prospects for addressing these limitations and plans for the near-real-time operational application of the VIDA system are discussed.