Hydrochemistry and water quality of shallow groundwater in the Tikrit area of Salah Al Din Province, Iraq

Salah Al-Din Provence is an active agriculture and population region. One of its primary water sources is groundwater, which suffers from a lack of information regarding water quality and hydrochemistry. In order to study those missing variables, 27 samples from wells of shallow tubes were collected for analyzing the relevant physicochemical indices that help to produce the Schoeller index, Piper diagram, and Gibbs plot. Piper diagram revealed a hydrochemistry behavior of different values along with the groundwater samples. The chemistry of wells was controlled primarily by the evaporation process according to the Gibbs plot. The values of the Schoeller index of the studied samples stated that 59% of them have disequilibrium in Chloro-Alkaline due to their negative obtained values while the rest of them produced positive estimates, which indicates an exchange reaction of cation–anion basic domination. It was concluded that carbonate and silicate weathering, as well as evaporation, controlled the region’ s hydrochemistry. Using Water Quality Index, groundwater was evaluated for use as drinking water. While using Sodium Adsorption Ratio, Sodium percentage, Residual Sodium Carbonate, Magnesium Hazard, and US salinity diagram were all used for estimating the same water’ s suitability for irrigation. All of those indicators, as well as the Gibbs ratio, show that all 27 samples were unsuitable for both studied usage. In addition, those results indicate that evaporation is a major problem for groundwater in this area. Finally, using cluster analysis it was concluded that there are two types of similarities that indicate different levels of pollution in groundwater.