Evaluation of the LI-710 evapotranspiration sensor in comparison to full eddy covariance for monitoring energy fluxes in perennial and annual crops
Year: 2025
Type: article
Abstract: Evapotranspiration (ET) is one of the most challenging hydrologic fluxes to measure in many environmental monitoring studies and agricultural water management. Traditional methods of measuring ET, such as using the eddy covariance (EC) system or lysimeters, can be costly, complex, and require specialized equipment and expert knowledge. There is an urgent need for simple, low-cost, but accurate ET sensors such as the LI-170. However, their accuracy has not been validated under different land covers. This study evaluates the performance of the LI710 ET sensor in comparison to the full eddy covariance (EC) systems across four distinct crops: three perennial crops (citrus, almond, and pistachio) and one annual crop (processing tomatoes) in California’s Central Valley, USA. In each orchard, the LI710 sensors were strategically co-located, with the EC systems equipped with a gas analyzer and wind anemometer to ensure precise measurements of fluxes. The LI710 sensor’s sensible heat flux (H) and latent heat flux (LE) measurements were adjusted using an energy balance closure correction, with independent measurements of net radiation (Rn) and soil heat flux (G) to improve accuracy. Without EBR correction, the LI710 sensor tended to underestimate ET values compared to the EC system, highlighting the importance of energy balance closure adjustments. Results indicate a strong correlation between the LI710 and EC systems, with correlation coefficients (R2) ranging from 0.84 to 0.99 and root mean square error (RMSE) values as low as 0.27 mm/day for ET, 9.63 W/m2 for H, and 7.63 W/m2 for LE. Both sensors effectively captured seasonal trends, with peak ET values observed during high water-demand summer periods. Minor discrepancies were noted during peak flux periods, particularly in complex canopies like citrus, where the LI710 sensor showed occasional over- or underestimations relative to the EC system. Nevertheless, the LI710 ET sensor’s overall accuracy suggests it is a reliable, cost-effective, easy-to-use alternative for continuous ET and energy flux monitoring, particularly if the EBR is implemented. These findings underscore the LI710 sensor's potential for hydrologic water balance monitoring and integration into precision irrigation systems, supporting real-time water management.
Source: Agricultural Water Management
Authors: Srinivasa Rao Peddinti, Isaya Kisekka
Institution: University of California, Davis
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $3,070
OpenAlex ID: W4409837172