Crops
; Crop coefficient
; Crop water requirements
; Food and agriculture organizations
; Penman-Monteith equations
; Priestley-Taylor
; Reference crop evapotranspirations
; Simplifying assumptions
; Technical notes
; Surface resistance
; evapotranspiration
; Food and Agricultural Organization
; Penman-Monteith equation
; water use
英文摘要:
The Matt-Shuttleworth method provides a way to make a one-step estimate of crop water requirements with the Penman-Monteith equation by translating the crop coefficients, commonly available in United Nations Food and Agriculture Organization (FAO) publications, into equivalent surface resistances. The methodology is based upon the theoretical relationship linking crop surface resistance to a crop coefficient and involves the simplifying assumption that the reference crop evapotranspiration (ET0) is equal to the Priestley-Taylor estimate with a fixed coefficient of 1.26. This assumption, used to eliminate the dependence of surface resistance on certain weather variables, is questionable; numerical simulations show that it can lead to substantial differences between the true value of surface resistance and its estimate. Consequently, the basic relationship between surface resistance and crop coefficient, without any assumption, appears to be more appropriate for inferring crop surface resistance, despite the interference of weather variables.
Institut de Recherche Pour le Développement (IRD), UMR LISAH, 2 Place Viala, Montpellier, France; Institut National Agronomique de Tunisie (INAT), 43 Avenue Charles Nicolle, Tunis, Tunisia
Recommended Citation:
Lhomme J,P,, Boudhina N,et al. Technical Note: On the Matt–Shuttleworth approach to estimate crop water requirements[J]. Hydrology and Earth System Sciences,2014-01-01,18(11)