Kodja D.J. auteur aut IRD Akognongbé A.J.S. auteur aut IRD Amoussou E. auteur aut IRD Mahé Gil auteur aut IRD Vissin E.W. auteur aut IRD Paturel Jean-Emmanuel auteur aut IRD Houndénou C. auteur aut IRD text conferencePaper eng text/pdf reformatted digital access The Ouémé watersheds at Bétérou and Bonou has been recently facing increased sensitivity to extreme hydroclimatic phenomena that occurred by flooding or drought events. In the same time, the population growth and the related socio-economic activities increased the pressure state on water resources. In this context, hydrological modeling is an important issue and this study aims at analyzing the calibration of the hydrological model GR4J based on PET Penman-Monteith and Oudin methods. Daily rainfall, Penman-Monteith and Oudin evapotranspiration and daily data flow from the Bétérou and Bonou hydrometric stations on the Ouémé Basin have been implemented in the GR4J model over the period 1971 to 2010. Oudin PET values are slightly higher than the Penman-Monteith PET ones. However, the difference between the two PET methods have only few impacts on the optimization and performance criteria of the GR4J model. The Nash values ranges from 0.83 to 0.91 in Bonou, and 0.52 to 0.70 in Bétérou for the calibration in dry period, while in validation, they are 0.59 to 0.78 in Bétérou, and 0.56 to 0.88 in Bonou in wet season. In view of these results, with the two PET methods used which do not result from the same climatic variables, it should be said that the formulation of PET has only few impacts on the results of GR4J for these tropical basins. specialized MODELE HYDROLOGIQUE CALIBRAGE ETALONNAGE EVAPOTRANSPIRATION POTENTIELLE ESTIMATION INONDATION SECHERESSE PRECIPITATION VARIATION JOURNALIERE DEBIT BASSIN VERSANT 1971 2010 MODELE GR4J EQUATION PENMAN-MONTEITH METHODE OUDIN AFRIQUE DE L'OUEST 062MECEAU06 Global FRIEND-Water Conference : Hydrological Processes and Water security in a Changing World, 8., Pékin (CHN), 2018/11/06-09 383 163-169 Yu Z. ed. edt IRD Lu C. ed. edt IRD Yu D.D. ed. edt IRD Cai J. ed. edt IRD Mahé Gil ed. edt IRD Mishra A. ed. edt IRD Cudennec C. ed. edt IRD Van Lanen H.A.J. ed. edt IRD Orange Didier ed. edt IRD Amani. A. ed. edt IRD Wallingford AISH 2020 https://www.documentation.ird.fr/hor/fdi:010082893 10.5194/piahs-383-163-2020 [F B010082893] https://www.documentation.ird.fr/hor/fdi:010082893 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2021-10/010082893.pdf IRD - Base Horizon / Pleins textes 2021-07-05 2025-02-24 fdi:010082893 fre