Estimation of Evapotranspiration Using Different Climate Models: A Case Study in Semi-arid Region-Libya


  • Mostafa Ali Benzaghta Faculty of Agriculture, Sirte University, Libya


Evapotranspiration, modeling, semi-arid region, statistical analysis and Libya


Evapotranspiration (ET) has a critical role in agricultural activity, water management and hydraulic engineering. Estimation of Evapotranspiration in arid and semi-arid regions, in particular, Libya is a very crucial issue. This paper aim to evaluate ET using three climate models (FAO-Penman-Monteith (P&M), Hargreaves-Samani and Penman). The daily and monthly meteorological data were collected from the year 2004 and 2005 from the study area. The measured meteorological variables include daily observations of air temperature, relative humidity, and wind speed. The statistical analysis was undertaken to verify the accuracy of the studied models. The results of the Hargreaves-Samani and Penman models are compared with FAO-Penman-Monteith model. Based on the model testing the statistical analysis show that the Penman model gave a better estimation than Hargreaves-Samani model.


Cobaner, M. 2011. Evapotranspiration estimation by two different neuro-fuzzy inference systems. Journal of Hydrology, 398(3): 292-302.

Wang, Y. M., Traore, S., and Kerh, T. 2009. Applying evapotranspiration reference model and rainfall contribution index for agricultural water management plan in burkina faso. African Journal of Agricultural Research, 4(12): 1493-1504.

Oki, T., and Kanae, S. 2006. Global hydrological cycles and world water resources.

science, 313: 1068-1072.

Naser, I. F., Asit, K. B., and Murad, J. B. 2001. Water management in islam (water resources management and policy series), United Nations University Press.

Alghariani, S. A. Future perspectives of irrigation in southern mediterranean region: Policies and management issues. In: Al-rasheed, m., singh, v.P., sheriff, m.M. (eds.).

International Conference on Water Resources Management in Arid Regions, Kuwait: 313–320

Hassan, F. A. 2004. Water and ethics: A historical perspective in: Series on water and ethics unesco. Paris.

Allen, R. G., Pereira, L. S., Raes, D., and Smith, M. 1998. Crop evapotranspiration: Guidelines for computing crop water requirements, Irrigation and Drainage Paper 56, FAO, Rome.

Sumner, D. M., and Jacobs, J. M. 2005. Utility of penman-monteith, priestley-taylor, reference evapotranspiration and pan evaporation methods to estimate pasture evapotranspiration. J. Hydrol. Eng., 308: 81-104.

Hargreaves, G. L., Hargreaves, G. H., and Riley, J. P. 1985. Agricultural benefits for senegal river basin. J. Irrigat. Drainage Eng, 111: 111-124.

France, J., and Thornley, J. 1984. Mathematical models in agriculture. Butterworths, london.

Amatya, D. M., Skaggs, R. W., and Gregory, J. D. 1996. Camparison of methods for estimating refet. J. Irrigat. Drainage Eng, 121(9).

Landeras, G., Ortiz-Barredo, A., and Lo pez, J. J. 2008. Comparison of artificial neural network models and empirical and semi-empirical equations for daily reference evapotranspiration estimation in the basque country northern spain. Agric. Water Manage, 95: 553-565.

Gavilán, P., Estévez, J., and Berengena, J. 2008. Comparison of standardized reference evapotranspiration equations in southern spain. . J. Irrigat. Drainage Eng., 134: 1-12.

Benzaghta, M. A., Mohammed, T. A., and Ekhmaj, A. I. 2012. Prediction of evaporation from algardabiya reservoir. Libyan Agriculture Research Center Journal International 3 (3): 120-128.

Hargreaves, G. H., and Allen, R. G. 2003. History and evaluation of hargreaves evapotranspiration equation. J. Irrigat. Drainage Eng, 129: 53-63.

Penman, H. L. 1963. Vegetation and hydrology. Technical committee no. 53, Common wealth bureau of soils, Harpenden, U.K.

Fox, D. G. 1981. Judging air quality model performance. Bull. Amer. Meteorol. Soc., 62: 599-609.

Willmott, C. J. 1982. Some comments on the evaluation of model performance. Bull. Amer. Meteorlo. Soc, 63: 1309-1313.

Jacovides, C. P., and Kontoyiannis, H. 1995. Statistical procedures for the evaluation of evapotranspiration computing models. Agric. Water Manage, 27: 365-371.