Abstract
The effects of weather measurement variability on Penman-Wright alfalfa reference evapotranspiration (ETr) estimates were investigated. Measurement variability or error was estimated in two ways(1) using manufacturers specifications of accuracy, and (2) by actual measurement. Results showed that evapotranspiration (ET) errors due to combined random and systematic error in weather measurements were less than 5.5% of average daily ETr when sensors were operating within error level envelopes equivalent to their specifications of accuracy. When sensors were operating at the limits of their specifications of accuracy, the greatest ET error was due to solar radiation measurement error, followed by dewpoint, maximum temperature, and wind speed measurement errors. Weather measurement variability derived from sensor evaluations resulted in different ET error. Air temperature measurement variability was small yielding ET errors less than 4% of average daily ET. Dewpoint temperature errors, based on relative humidity measurement error of 10%, resulted in ET errors of about 6 to 7% of average daily ET. Solar radiation measurement variability resulted in ET errors of nearly 8.5% of average daily ET.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
