Evapotranspiration Estimates in Extremely Arid Areas

Abstract

Consumptive use or evapotranspiration is an important element for estimating irrigation water requirements and in water resources management, especially under arid conditions where fresh water is a limited resource. In this study, 23 empirical methods have been selected from the literature and used for estimating consumptive use (or evapotranspiration) under the extremely arid conditions of central Saudi Arabia using the corresponding climatic data collected from the Hofuf station. The results from these methods have been evaluated with reference to actual measurements performed in the same area in two separate 12‐mo periods and then ranked according to five different rating criteria. The top six ranked methods obtained for the average as well as for Salih and Sendil's ratings are ranked in the following order of merit: Jensen‐Haise, class A pan, Ivanov, adjusted class A pan, Behnke‐Maxey, and Stephens‐Stewart.