Assessment of Different Methods of the Estimation of  Reference Evapotranspiration  by FAO’s Evaporation  Pan method in  Catchment Basin of East And South Eastern of The Country

Joshani, A.; Khoshhal, J.; Zaree Abyaneh, H.

Assessment of Different Methods of the Estimation of Reference Evapotranspiration by FAO’s Evaporation Pan method in Catchment Basin of East And South Eastern of The Country

Document Type : ترویجی

Authors

A. Joshani ¹

J. Khoshhal ²

H. Zaree Abyaneh ³

¹ phd student

² Associate Prof. in Climatology, University of Isfahan

³ Associate Prof of water engineering faculty, University of Abu Ali Sina

Abstract

Assessment of reference evapotranspiration to estimate aqueous Plants’ needs, to Manage aquatic and drainage plans and irrigation timing of plants are some necessities of agriculture section. So in this research to find the best model for estimation of reference evaporation and transpiration for catchment basin of East And South Eastern of the Country, relying on clustering method and considering data made by 66 weather stations, reference evaporation and transpiration made by evaporation basin was assessed and compared to evaporation and transpiration measures of 8 equations based on statistical parameters: r, t, d, MAE, MBE, NRMSE.
Based on the results, considering the different time dimensions, the methods Hargreaves - Samani, Blaney – Criddle - FAO 24 , Turk and Priestley – Taylor, have the best conformity with reference evapotranspiration values resulted by evaporation pan. Also the results of research show that in seasonal scale, summer had the minimum and winter had the maximum estimation error of .On the other hand, monthly scale had the minimum error compared to seasonal scale. This result show decrease in error in small time scales.

Keywords

Clustering

Hargreaves - Samani

Blaney Criddle -FAO 24

Turk

Priestley - Taylor

Subjects