Evapotranspiration estimation using SMAP soil moisture products and Bouchet complementary evapotranspiration over Southern Great Plains

WALKER ELISABET; GARCIA GABRIEL; VENTURINI VIRGINIA

JOURNAL OF ARID ENVIRONMENTS

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2019 vol. 163 p. 34 - 40

0140-1963

Evapotranspiration (ET) is an important water withdrawal in the water balance, particularly in arid and semiarid regions. In this study, a formulation to derive the relative evapotranspiration (β) and ET from in situ and passive microwave data, is presented. The original Komatsu´s β equation was modified by introducing a calibration parameter to eliminate the wind speed effects. Then, a simple formulation to estimate mean daily ET was obtained by combining the β parameter, Bouchet´s complementary relationship, and Priestley-Taylor´s equation. Estimates of β and ET were compared with ground observations in the study area, Southern Great Plains (SGP). These comparisons suggest that β characterizes the relative evapotranspiration behavior in the region. Besides, ET results show a good agreement with ground data, yielding a root mean square error and bias of 28.5 and −6 W/m2, respectively. The proposed approach took advantages of passive microwave images, combining them with ground observations in a simple and robust equation