hydrochemical and stable isotope (δ18o and δ2h) characteristics of khorasan razavi rivers

iran located in arid and semi-arid region faces dramatic water shortage crisis mainly in large and populated provinces. surface water resources plays dominant role to provide irrigation and potable water usages in khorasan razavi province. in this study, 1112 hydro chemical analyses from 25 river stations in khorasan razavi province north-eastern iran have been studied to determine the main parameters controlling river water quality. the results demonstrated that rock weathering with simultaneous dissolution of evaporative, carbonate and silicate minerals is dominant factor controlling river water quality. stable isotopes δ¹⁸o and δ²h in some of the rivers and two main dam reservoirs kardeh and torogh demonstrated that river water samples mainly plot below mashahd meteoric water line between eastern mediterranean meteoric water line and global meteoric water line and show negligible deviation due to low evaporation. however, dam reservoir samples show notable deviation from meteoric water lines due to huge evaporation from their surfaces.