Performance of Twelve Mass Transfer Based Reference Evapotranspiration Models under Humid Climate
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Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Water Resource and Protection
Abstract
Reference evapotranspiration is very important parameter in the hydrological,
agricultural and environmental studies and is accurately estimated by the
FAO Penman-Monteith equation (FAO-PM) under different climatic conditions.
However, due to data requirement of the FAO-PM equation, there is a
need to investigate the applicability of alternative ETo equations under limited
data. The objectives of this study were to evaluate twelve mass transfer based
reference evapotranspiration equations and determine the impact of ETo equation
on long term water management sustainability in Tanzania and Kenya.
The results showed that the Albrecht, Brockamp-Wenner, Dalto, Meyer,
Rohwer and Oudin ETo equations systematically overestimated the daily ETo
at all weather stations with relative errors that varied from 34% to 94% relative
to the FAO-PM ETo estimates. The Penman, Mahringer, Trabert, and the
Romanenko equations performed best across Tanzania and the South Western
Kenya with root mean squared errors ranging from 0.98 to 1.48 mm/day,
which are relatively high and mean bias error (MBE) varying from −0.33 to
0.02 mm/day and the absolute mean error (AME) from 0.79 to 1.16 mm/day.
For sustainable water management, the Trabert equation could be adopted at
Songea, the Mahringer equation at Tabora, the Dalton and/or the Rohwer equations
at Eldoret, the Romanenko equation at Dodoma, Songea and Eldoret.
However, regional calibration of the most performing equation could improve
water management at regional level.
Description
Keywords
Reference Evapotranspiration, Mass Transfer, Eastern Africa, Water
Citation
Djaman, K., Koudahe, K., Sall, M., Kabenge, I., Rudnick, D. and Irmak, S. (2017) Performance of Twelve Mass Transfer Based Reference Evapotranspiration Models under Humid Climate. Journal of Water Resource and Protection, 9, 1347-1363. https://doi.org/10.4236/jwarp.2017.912086