EFFECTS OF WEATHER ON EVAPORATION FROM BELLANI PLATES AND EVAPOTRANSPIRATION FROM LYSIMETERS

Abstract

Evaporation and evapotranspiration were measured in 1958 and 1959. Bellani plate evaporimeters proved to be just as reliable as Class A pans and more convenient. Evapotranspiration was determined on alfalfa, ladino clover and brome grass growing in lysimeters. Temperature, radiation, wind and dew-point were also determined. On a daily or weekly basis, temperature gave the highest correlations with evapotranspiration, but on a 2-hour basis radiation gave the highest correlations. All four weather elements were found by partial correlation to have highly significant effects on both evaporation and evapotranspiration. Their effects on evaporation were quite similar to their effects on evapotranspiration. It is concluded that, if weather records are used to estimate evapotranspiration, all four of them should be used. Judging by the direct correlations, better estimates of evapotranspiration can be obtained using evaporation records than using any one weather record by itself.