Simple Equations for Estimating Reference Evapotranspiration in an Arid Climate, Saudi Arabia PDF

Keywords

equations, climate, Saudi Arabia

Abstract

Simple equations, based on easily available climatic data, were developed for the reference evapotranspiration (ET) in an arid climate of Saudi Arabia, taking 20 cm-tall alfalfa as a reference crop. These equations could be used in conjunction with crop coefficients to estimate the crop water requirements in irrigation practice, research work and computerized irrigation systems. The study was carried out with four non-weighing, freely drained, steel lysimeters having an actively growing dense cover of alfalfa, and surrounded on all sides by an alfalfa belt. The crop was frequently irrigated and the evapotranspiration was obtained by balancing the water inputs and outputs to the lysimeters. Equations based on the most important climatic variables were then fitted to the data.