تقدير الاحتياجات المائية الشهرية للمحصول المرجعي في الإحساء

Abstract EN

Knowledge of reference crop water requirements {CWR0) in arid regions, where crop production depends on irrigation, is a prerequisite for economical crop production as well as sustainable soil and groundwater development.

Field measurements of CWR0 are not available for Hassa oasis, which represents the largest and the most important oasis in Saudi Arabia.

Previous estimates of CWR0 were based on empirical and semi-empirical methods that have been proven by international organizations (FAO, ICID, and WMO) to be unreliable.

Monthly CWR0 in Hassa oasis were estimated using the physically based FAO Penman-Monteith equation which has been recommended by leading international organization as the only acceptable method for estimating CWR0 to supersede previous estimates.

The results showed that monthly CWR0 in Hassa ranges from 81.53 mm in December and January to 255.75 mm in July, with annual total of 1980.67 mm.

Overestimation of CWR0 in Hassa by previous empirically based methods compared to FAO Penman-Monteith equation estimates ranges from 8% to 36% on annual bases.

Such overestimation of CWR0 in Hassa oasis by previous empirically based methods necessitates recalculation of actual crop water requirements in Hassa using the current CWR0 estimates for better irrigation management and more sustainable development of both soil and groundwater resources in the oasis.