The effects of local and regional parameters on the delta O-18 and delta H-2 values of precipitation and surface water resources in the Middle East

Located in semi-arid and arid regions in the world, the Middle East has always faced water shortage crisis. Therefore, water resources in this area should be studied by accurate methods such as the stable isotope technique. The results of the current isotopic study show the effects of the main local (temperature and precipitation) and regional parameters (teleconnection indices) on the delta O-18 values of precipitation and surface water resources across the Middle East. Plotting the values of delta O-18 vs delta H-2 in some of the major rivers in the Middle East on the local meteoric water lines shows that the surface water resources are dominantly recharged by local precipitation, while the deviation observed in some samples is due to evaporation. The contributions of various air masses (the precipitation events originating from the main air masses) in the recharge of the principal rivers have also been studied. The results of the mixing models demonstrate that the contributions of various air masses in the recharge of rivers vary significantly across the Middle East.

Automated summary

The use of stable isotope techniques in studying water resources in the Middle East reveals the influence of local climate factors on precipitation and surface water resources, as well as the significant variation in contributions from different air masses in the recharge of rivers across the region.