Analyses, calibration and validation of evapotranspirationmodels to predict grass-reference evapotranspiration in theSenegal river delta

Authors

Koffi Djaman, Africa Rice CenterFollow
Hossein Tabari, KU Leuven
Alpha B. Balde, Africa Rice Center
Lamine Diop, Universite Gaston Berger
Koichi Futakuchi, Africa Rice Center
Suat Irmak, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2016

Citation

Journal of Hydrology: Regional Studies 8 (2016) 82–94

Comments

© 2016 The Author(s).

http://dx.doi.org/10.1016/j.ejrh.2016.06.003

Abstract

Study region: Grass-reference evapotranspiration estimation by the Penman-Monteithmethod (PM-ETo) requires a number of climate variables which are not always availableat all weather stations. Different alternative ETo equations have been developed and theirutilization for various local climate conditions requires analyses of their accuracy as com-pared to the standardized Penman-Monteith method. There is a significant lack of data andinformation on this topic in the Senegal River Delta (SRD). Study focus: The objective of this study was to evaluate, calibrate and validate six EToequations ((Trabert, Mahringer, Penman1948, Albrecht, Valiantzas1 and Valiantzas2) forthe SRD. Although all six equations showed good agreement with the PM-ETo (R²> 0.60)for daily ETo estimates, the Valiantzas2 equation was the best model for the Senegal RiverDelta and had the lowest root mean squared difference (RMSE) of 0.45 mm/day and thelowest percent error of estimate (PE) about 7.1%. New hydrological insights for the region: In the case of data limitations, the equationscalibrated in this study are recommended for ETo estimation in the Senegal River Delta. Theresults of this study could be used by agricultural producers, crop consultants, universityresearchers, policy makers for the agricultural, hydrological, and environmental studies aswell as proper allocation and use and forecasting in the SRD where lowland irrigated riceis predominant.