EVALUATION OF GROUNDWATER QUALITY OF THE UPPER ALLUVIAL FAN AQUIFER AND ITS POTENTIAL USES FOR DIFFERENT PURPOSES IN THE TERSAQ AREA, EAST IRAQ
The present study is devoted to evaluate groundwater quality and its suitability for different purposes in the Tersaq Area. The study area is an arid region located in eastern Iraq at the border between Iraq and Iran, covering an area of 1730 Km2, mainly covered by the Quaternary sediments (alluvial fans and sheet run off sediments). It suffers water scarcity exacerbated lately by climate change, and increasing control of river water flow from the Iranian side by hydraulic structures. Forty water samples are collected from wells penetrating the alluvial fan, springs gushing at the up and down slope of the fan and water appearing in the course of the perenneil streams in the area during wet and dry seasons. The samples are analyzed for major cations and anions as well as for minor ions: hydrogen sulfide gas, fluoride, and physiochemical properties and trace elements (Ba, Zn, Cu, P, Ni, Cd, Co and Cr). The results show that most water samples are brackish with either chloridic or sulphatic water type that are suitable to irrigate some salt-tolerant crops such as wheat, barley and palms, and only so due to the good infiltration capacity of the soil and its low sodium absorption ratio. They are also suitable for livestock drinking. However, the water of the springs spreading along the Himreen Mountain flank is of fresh type suitable for human drinking. The main factors affecting water chemistry are evaporation process and the dissolution of the evaporitic rocks such as gypsum and anhydrite.