Olivera-Guerra L. E., Laluet P., Altes V., Ollivier Chloé, Pageot Y., Paolini G., Chavanon E., Rivalland V., Boulet Gilles, Villar J. M., Merlin O. (2023). Modeling actual water use under different irrigation regimes at district scale : application to the FAO-56 dual crop coefficient method. Agricultural Water Management, 278, 108119 [15 p.]. ISSN 0378-3774.
Titre du document
Modeling actual water use under different irrigation regimes at district scale : application to the FAO-56 dual crop coefficient method
Année de publication
2023
Auteurs
Olivera-Guerra L. E., Laluet P., Altes V., Ollivier Chloé, Pageot Y., Paolini G., Chavanon E., Rivalland V., Boulet Gilles, Villar J. M., Merlin O.
Source
Agricultural Water Management, 2023,
278, 108119 [15 p.] ISSN 0378-3774
The modeling of irrigation in land surface models are generally based on two soil moisture parameters SMthreshold and SMtarget at which irrigation automatically starts and stops, respectively. Typically, both parameters are usually set to optimal values allowing to fill the soil water reservoir with just the estimated right amount and to avoid crop water excess at all times. The point is that agricultural practices greatly vary according to many factors (climatological, crop, soil, technical, human, etc.). To fill the gap, we propose a new calibration method of SMthreshold and SMtarget to represent the irrigation water use in any (optimal, deficit or even over) irrigation regime. The approach is tested using the dual-crop coefficient FAO-56 model implemented at the field scale over an 8100 ha irrigation district in northeastern Spain where the irrigation water use is precisely monitored at the district scale. Both irrigation parameters are first retrieved at monthly scale from the irrigation observations of year 2019. The irrigation simulated by the FAO-56 model is then evaluated against observations at district and weekly scale over 5 years (2017-2021) separately. The performance of the newly calibrated irrigation module is also assessed by comparing it against three other modules with varying configurations including default esti-mates for SMthreshold and SMtarget. The proposed irrigation module obtains systematically the best performance for each of the 5 years with an overall correlation coefficient of 0.95 +/- 0.02 and root-mean square error of 0.27 +/- 0.07 hm3/week (0.64 +/- 0.17 mm/day). Unlike the three irrigation modules used as benchmark, the new irrigation module is able to reproduce the farmers' practices throughout the year, and especially, to simulate the actual water use in the deficit and excess irrigation regimes occurring in the study area in spring and summer, respectively.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Bioclimatologie [072]
;
Télédétection [126]
Description Géographique
ESPAGNE
Localisation
Fonds IRD [F B010086896]
Identifiant IRD
fdi:010086896
