What is it? The Reference Evapotranspiration Calculator (C-ETo) is a tool developed by the Water Measured Research Project Team at the State University of Mato Grosso (UNEMAT).

Objective: To facilitate calculations of the constant (kp) of the Class A Tank Evaporimeter (TCA) based on environmental data Surround, Wind Speed ​​and Relative Humidity. This methodology is recommended and used to estimate Potential or Reference Evapotranspiration (ETo = ETP) based on measurements from the Class A Tank and local meteorological data.

Once you have the kp value, ETo is calculated by multiplying this constant by the Evaporation measured on the TCA Evaporimeter.

Input Data

Border: Strip of vegetation (grass) around the Class A Tank, in m. Recommended 10 m;

Wind Speed: Average daily wind speed at 2 m height, in m/s.

Relative Humidity: Average Relative Air Humidity, in %.

Note: To calculate kp and ETo for other periods (weekly, ten-yearly, monthly, etc.) use the average of V, RH and Evaporation for the period.

Queiroz, T. M.; Milani Junior, J.; Justino, M. P. Water App Measured: Reference Evapotranspiration Calculator.