@article{fdi:010081269,
  title = {{I}mplementing a new texture-based soil evaporation reduction coefficient in the {FAO} dual crop coefficient method},
  author = {{A}mazirh, {A}. and {M}erlin, {O}. and {E}r-{R}aki, {S}. and {B}ouras, {E}. and {C}hehbouni, {A}bdelghani},
  editor = {},
  language = {{ENG}},
  abstract = {{C}rop evapotranspiration ({ET}) is a fundamental component of the hydrological cycle, especially in arid/semi-arid regions. {T}he {FAO}-56 offers an operational method for deriving {ET} from the reduction (dual crop coefficient {K}c) of the atmospheric evaporative demand ({ET}0). {T}he dual coefficient approach ({FAO}-2{K}c) is intended to improve the daily estimation of {ET} by separating the contribution of bare soil evaporation ({E}) and crop transpiration components. {T}he {FAO}-2{K}c has been a well-known reference for the operational monitoring of crop water needs. {H}owever, its performance for estimating the water use efficiency is limited by uncertainties in the modeled evaporation/transpiration partitioning. {T}his paper aims at improving the soil module of the {FAO}-2{K}c by modifying the {E} reduction coefficient ({K}r) according to soil texture information and state-of-the-art formulations, hence, to amend the mismatch between {FAO}-2{K}c and field-measured data beyond standard conditions. {I}n practice this work evaluates the performance of two evaporation models, using the classical {K}r ({K}r,{FAO}) and a new texture-based {K}r ({K}r,text) over 33 bare soil sites under different evaporative demand and soil conditions. {A}n offline validation is investigated by forcing both models with observed soil moisture (?s) data as input. {T}he {K}r,text methodology provides more accurate {E} estimations compared to the {K}r,{FAO} method and systematically reduces biases. {U}sing {K}r,text allows reaching the lowest root means square error ({RMSE}) of 0.16 mm/day compared to the {K}r,{FAO} where the lowest {RMSE} reached is 0.88 mm/day. {A}s a step further in the assessment of the proposed methodology, {ET} was estimated in three wheat fields across the entire agricultural season. {B}oth approaches were thus inter-compared in terms of {ET} estimates forced by {SM} estimated as a residual of the water balance model (online validation). {C}ompared to {ET} measurements, the new formulation provided more accurate results. {T}he {RMSE} was 0.66 mm/day (0.71 mm/day) and the {R}2 was 0.83 (0.78) for the texture-based (classical) {K}r.},
  keywords = {{FAO}-2{K}c ; {S}oil evaporation ; {S}oil texture ; {S}oil moisture ; {E}vapotranspiration},
  booktitle = {},
  journal = {{A}gricultural {W}ater {M}anagement},
  volume = {250},
  numero = {},
  pages = {106827 [15 ]},
  ISSN = {0378-3774},
  year = {2021},
  DOI = {10.1016/j.agwat.2021.106827},
  URL = {https://www.documentation.ird.fr/hor/fdi:010081269},
}