Validation and Bias Correction of Forecast Reference Evapotranspiration for Agricultural Applications in Nevada

Accurate estimates of reference evapotranspiration (ET0) are critical for estimating actual crop evapotranspiration (AET) and agricultural water use. Measuring AET to estimate consumptive water use can be difficult and expensive while ET0 estimates can be obtained from readily available weather station data or gridded weather data. Forecasts of the weather variables needed to estimate ET0 are also readily available and have the potential to be used by agricultural producers for irrigation scheduling with the ultimate goal of reducing unnecessary crop water use. However, most forecast models do not account for agriculture and irrigation leading to large biases in forecasted ET0.

The goals of this project are to evaluate how well ET0 forecasts from the National Weather Service Forecast Reference Evapotranspiration product perform compared to observations in agricultural settings across Nevada. The project team, led by researchers at the Desert Research Institute, will establish biases between forecasts and observations that can then be used to bias-correct real-time forecasts for agricultural applications such as irrigation scheduling. The initial work for this project is focused on Nevada, but the methods can be applied in other regions and ongoing work will conduct a similar study across the entire United States.

For more information about this NIDIS-funded research, view the project's research profile or contact Amanda Sheffield (amanda.sheffield@noaa.gov).