Evaluation of empirical methods for estimating reference evapotranspiration in Central High Lands and Arid Western Lowlands of Eritrea
DOI:
https://doi.org/10.54386/jam.v27i3.3073Keywords:
Cumulative Performance Index (CPI), Reference evapotranspiration (ETo), FAO56-PM, Hargreaves-Samani, Blaney-Criddle, SchendelAbstract
FAO Penman-Monteith (FAO56-PM) method remains difficult to implement across Eritrea due to severe shortages of standardized meteorological data. This study evaluated the accuracy of five alternative empirical methods by comparing them with the FAO56-PM model using established performance metrics (R², RRMSE, NSE, %MBE, and MAPE). Cumulative Performance Index (CPI) was used to determine the overall performances of five alternative ETo methods. The study identified the modified Hargreaves-Samani (CPI=3.6), Romanenko (CPI=3), and Schendel (CPI=2.6) methods as the most viable simplified alternatives for the data-scarce Central Highlands. However, no method proved optimal for the Arid Western Lowlands. Hargreaves-Samani and Blaney-Criddle methods performed poorly, with combined CPI values of 1.7 and 1.4, respectively. The findings suggest that the modified Hargreaves-Samani and Romanenko methods can effectively replace the FAO56-PM model for estimating crop water requirements in both irrigated and rainfed agricultural systems across all crop types in the Central Highlands. However, the study underscores the critical need for rigorous local calibration and validation of the Hargreaves-Samani, Blaney-Criddle, and Schendel methods to enhance their accuracy.
References
Abdelraouf, R. E., El-Shawadfy, M. A., Bakry, A. B., Abdelaal, H. K., El-Shirbeny, M. A., Ragab, R., and Belopukhov, S. L. (2024). Estimating ETO and scheduling crop irrigation using Blaney–Criddle equation when only air temperature data are available and solving the issue of missing meteorological data in Egypt. BIO Web Conf., 82: 02020. https://doi.org/10.1051/bioconf/20248202020
Allen, R. G., Pereira, L. S., Raes, D., and Smith, M. (1998). Crop evapotranspiration: Guidelines for computing crop water requirements (FAO Irrigation and Drainage Paper No. 56). Food and Agriculture Organization of the United Nations (FAO). https://www.fao.org/3/X0490E/X0490E00.htm
Djaman, K., Balde, A. B., Sow, A., Muller, B., Irmak, S., N’Diaye, M. K., Manneh, B., Moukoumbi, Y. D., Futakuchi, K., and Saito, K. (2015). Evaluation of sixteen reference evapotranspiration methods under Sahelian conditions in the Senegal River Valley. J. Hydrol. Reg. Stud., 3: 139–159. https://doi.org/10.1016/j.ejrh.2015.02.002
Dong, J., Xing, L., Gong, D., Cui, N., Guo, L., Liang, C., Zhao, L., Wang, Z., and Gong, D. (2024). Estimating reference crop evapotranspiration using optimized empirical methods with a novel improved Grey Wolf Algorithm in four climatic regions of China. Agric. Water Manag., 291: 108620. https://doi.org/10.1016/j.agwat.2023.108620
Fessehaye, M., Franke, J., and Brönnimann, S. (2022). Evaluation of satellite-based (CHIRPS and GPM) and reanalysis (ERA5-Land) precipitation estimates over Eritrea. Meteorol. Z., 31(5):401-413. DOI: 10.1127/metz/2022/1111
Hargreaves, G. H., and Samani, Z. A. (1985). Reference crop evapotranspiration from temperature. Appl. Eng. Agric., 1(2), 96–99. https://doi.org/10.13031/2013.26773
Kalekar, S. P., and Krishnamurthy, K. N. (2018). Comparison of temperature-based reference evapotranspiration methods with FAO 56 Penman-Monteith method. Mysore J. Agric. Sci., 52(1): 12-17.
Kumar, S., Kumar, R., Singh, M. K., Yadav, S., Parhi, P. K., and Bardhan, A. (2024). Crop water requirement of rice in different agroclimatic zones of Jharkhand. J. Agrometeorol., 26(2): 233-237. https://doi.org/10.54386/jam.v26i2.2358
Meshram, D. T., Gorantiwar, S. D., Mittal, H. R., and Puronit, R. C. (2010). Comparison of reference crop evapotranspiration methods in western part of Maharashtra state. J. Agrometeorol.,12(1): 44-46. https://doi.org/10.54386/jam.v12i1.1266
MoA. (2012). Ministry of Agriculture Eritrea. Investment potential in agricultural sector in Eritrea: National report.
Oudin, L., Hervieu, F., Michel, C., Perrin, C., Andréassian, V., Anctil, F., and Loumagne, C. (2005). Which potential evapotranspiration input for a lumped rainfall–runoff model? Part 2—Towards a simple and efficient potential evapotranspiration model for rainfall–runoff modelling. J. Hydrol., 303(1–4): 290–306. https://doi.org/10.1016/j.jhydrol.2004.08.026
Rao, A.K., and Wani, S. P. (2011). Evapotranspiration paradox at a semi-arid location in India. J. Agrometeorol., 13(1):3-8. https://doi.org/10.54386/jam.v13i1.1326
Ravazzani, G., Corbari, C., Morella, S., Gianoli, P., and Mancini, M. (2012). Modified Hargreaves-Samani equation for the assessment of reference evapotranspiration in Alpine River Basins. J. Irrig. Drain. Eng., 138(7): 592–599. https://doi.org/10.1061/(ASCE)IR.1943-4774.0000453
Sabziparvar, A.-A., and Tabari, H. (2010). Regional estimation of reference evapotranspiration in arid and semiarid regions. J. Irrig. Drain. Eng., 136(10): 724–731. https://doi.org/10.1061/(ASCE)IR.1943-4774.0000242
Saikia, U. S., Satapathy, K. K., Goswami, B., and Lama, T. D. (2005). Estimation of PET by empirical models for north eastern hill region of Meghalaya. J. Agrometeorol., 7(2), 265–273. https://doi.org/10.54386/jam.v7i2.855
Sarma, A., and Bharadwaj, K. (2020). Determination of crop-coefficients and estimation of evapotranspiration of rapeseed using lysimeter and different reference evapotranspiration models. J. Agrometeorol., 22(2): 172-178. https://doi.org/10.54386/jam.v22i2.158
Saxena, R., Tiwari, A., Mathur, P., and Chakravarty, N. V. K. (2020). An investigation of reference evapotranspiration trends for crop water requirement estimation in Rajasthan. J. Agrometeorol., 22(4): 449-456. https://doi.org/10.54386/jam.v22i4.447
Tabari, H., Grismer, M. E., and Trajkovic, S. (2011). Comparative analysis of 31 reference evapotranspiration methods under humid conditions. Irrig. Sci., 31: 107–117. https://doi.org/10.1007/s00271-011-0295-z
Downloads
Published
How to Cite
Issue
Section
Categories
License
Copyright (c) 2025 T. W. GHEBRETNSAE, E. S. MOHAMED, A. B. BOKRE, T. TESFAY, W. OGBAZGHI
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
This is a human-readable summary of (and not a substitute for) the license. Disclaimer.
You are free to:
Share — copy and redistribute the material in any medium or format
Adapt — remix, transform, and build upon the material
The licensor cannot revoke these freedoms as long as you follow the license terms.
Under the following terms:
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
NonCommercial — You may not use the material for commercial purposes.
ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
Notices:
You do not have to comply with the license for elements of the material in the public domain or where your use is permitted by an applicable exception or limitation.
No warranties are given. The license may not give you all of the permissions necessary for your intended use. For example, other rights such as publicity, privacy, or moral rights may limit how you use the material.
