Evaporation is an important component of the water balance in Israel. In nature, the evaporation process refers to the transfer of liquid water from plants, soils and water surfaces into the air as water vapor.
As a result of the current water crisis we are now publishing daily evaporation from several sites, in order to have more precise information on plant water losses. We are providing observed values from meteorological class A evaporation pans, and calculated potential evapotranspiration by the FAO Penman - Monteith method.
The class A pan is a device in which the daily water loss is measured according to the change of the water level. The water loss from the pan is generally higher than the water loss from crops but adjustments for water loss of specific crops may be estimated from the class A pan.
The calculated potential evapotranspiration method of Penman - Monteith, which assumes an unlimited water supply, depends on temperature, relative humidity, global radiation and wind, and generally provides a better representation of crop-water losses and requirements.