Variability of crop coefficients in space and time - examples from California

Abstract

Crop coefficients are calculated for almonds, citrus, and grapes in California based on a combination of remote sensing of actual crop evapotranspiration from the Surface Energy Balance Algorithm for Land (SEBAL®) and ground-based reference evapotranspiration from the California Irrigation Management Information System (CIMIS). Crop coefficients are calculated at the field scale, and the apparent variability in crop coefficients among fields and over time is examined. Crop coefficients derived from remote sensing are compared to published values used with reference evapotranspiration for estimation of crop water use. The opportunity to refine crop coefficients for irrigation management and water resources planning through improved understanding of the variability in crop water use via remotely sensed crop evapotranspiration estimates is discussed.