Conversion between evapotranspiration references and methods

摘要

Ratios of reference evapotranspiration for alfalfa (ET_r) and for grass (ET_o) are evaluated using measured ET_r and ET_o from lysimeter systems at Kimberly, Idaho and Bushland. Texas, In addition, ratios are evaluated using estimates by the KimberlyPenman and ASCE Penman-Monteith evapotranspiration methods. An ET reference conversion equation from FAO-56 is also compared.The ASCE-PM and Kimberly Penman methods predict differently for both ET_r and ET_o so that ratios of ET_r / ET_o computed from both methods behave differently Ratios of ET_r / ET_o from lysimeter measurements averaged 1.15 at both locations.