Location: Hydrology and Remote Sensing LaboratoryTitle: The influence of environmental conditions on the surface fluxes from adjacent vineyards in California’s Central Valley
|Kustas, William - Bill|
|HIPPS, L.E. - Utah State University|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/5/2018
Publication Date: N/A
Technical Abstract: California is among the largest wine-producing regions in the world. It’s also a region where the growing demand for dwindling water resources underscores the need for effective water management strategies to ensure the long-term sustainability of agriculture. Using data collected between 2013 and 2017 at a pair of adjacent vineyards as a part of the GRAPEX project, this study sought to understand how surface fluxes varied in response to changing environmental conditions at a pair of adjacent vineyards in the Central Valley of California. While both vineyards were planted with the pinot noir varietal of grapes (Vitis vinifera) and shared similar management practices, they differed in vineyard age, vegetation density, and in some case irrigation. Although meteorological conditions (wind speed, air temperature, and humidity) were similar for all years during the study, there were meaningful inter-site and inter-annual differences in the surface fluxes, particularly during the growing season. The average difference in the sensible heat flux measured over the growing season ranged from 10 W m-2 to 50 W m-2 and averaged 28 W m-2 (30%) over the whole of the study, Similarly, the difference in the measurements of the latent heat flux during the growing season ranged between 10 W m-2 and 80 W m-2 and averaged 32 W m-2 (10%). With coefficients of determination (r2) in excess of 0.90, the differences in these fluxes can be largely explained by differences in leaf area index and soil moisture content. In turn, both of these quantities are dependent on vineyard management practices; vegetation density depends on pruning and training practices while soil moisture content depends on irrigations practices. Thus, the results of this work not only provide insights into the factors regulating the surface fluxes, the also underscore the importance of management decisions for ensuring water resources are used effectively.