Title: Analysis of potential evapotranspiration using 11 modified temperature-based models

Authors: Mohammad Valipour; Saeid Eslamian

Addresses: Department of Water Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran ' Department of Water Engineering, Isfahan University of Technology, Isfahan 8145683111, Iran

Abstract: The evapotranspiration was estimated using 11 temperature-based models and was compared with the FAO Penman-Monteith model. The results showed that the modified Hargreaves-Samani models estimate the evapotranspiration better than the other models in the most provinces of Iran. However, the values of R² were less than 0.98 for 15 provinces of Iran. Therefore, the models were calibrated and precision of estimation was increased (the values of R² were less than 1.00 (with respect to two decimal numbers) for only five provinces in the modified models). The temperature-based models estimated the evapotranspiration in the north east and south west provinces of Iran better than other provinces. The best precise methods were the modified Hargreaves-Samani 1 method for AL (before calibration) and the Hargreaves-Samani method for AR, the Modified Hargreaves-Samani 2 method for SE and GH, the modified Hargreaves-Samani 1 for FA, and the modified Hargreaves-Samani 3 for MZ (after calibration).

Keywords: model calibration; evapotranspiration; FAO Penman Monteith model; Hargreaves Samani models; Iran; temperature based modelling.

DOI: 10.1504/IJHST.2014.067733

International Journal of Hydrology Science and Technology, 2014 Vol.4 No.3, pp.192 - 207

Received: 07 Mar 2014
Accepted: 26 Aug 2014
Published online: 07 Mar 2015 *

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