Hydrochemistry of shallow groundwater and its assessment for drinking and irrigation purposes in Tarmiah district, Baghdad governorate, Iraq

• Published in: Groundwater for sustainable development 2020-04, Vol.10, p.100300, Article 100300
• Main Authors: Ismail, Alhassan H., Hassan, Ghanim, Sarhan, Abdul-Hadi
• Format: Article
• Language: English
• Subjects: Cluster analysis; Groundwater quality; Hydrochemistry; Tarmiah district
• ISSN: 2352-801X; 2352-801X
• DOI: 10.1016/j.gsd.2019.100300

The present study evaluates the hydrochemistry of shallow groundwater and its suitability for drinking and irrigation purposes in Tarmiah district, Baghdad governorate, Iraq. Tarmiah is located in the north of Baghdad and represents an important area for a study due to its human and agriculture activity in addition to lack of information. Twenty groundwater samples were collected from shallow tube wells and analyzed for various related physicochemical tests to produce the relevant piper diagram, Gibbs plot, and Schoeller index values. Piper diagram revealed that there is a broad variation in hydrochemical properties. Gibbs plot showed a remarkable impact on water chemistry due to evaporation. The Schoeller index values demonstrate that 60% of samples are with negative values which in turn show the disequilibrium in a chloro-alkaline relationship while the rest (40%) admit a direct base exchange reaction “cation-anion” as a result of their positive values. The hydrochemistry of the region is dominated by evaporation, silicate and carbonate weathering. To estimate whether the samples are drinkable or not, Water Quality Index (WQI) method was followed. On the other hand, Magnesium Hazard (MH), US salinity and Wilcox diagrams were used as a relevant indication for irrigation usability. The results have shown that the quarter of the samples were suitable for both studied purposes. Statistically, the multivariate methods were used by applying Q and R mode cluster analysis (CA) on the groundwater quality data. The conclusion upon this was finding three kinds of pollution levels for the whole samples. R mode CA revealed two main groups indicating that the study area is influenced by natural processes and anthropogenic sources. [Display omitted] •The evaporation and silicate weathering have the highest impact on the groundwater quality in Tarmiah district.•The results shown that the quarter of the groundwater samples were suitable for drinking purposes.•Only six groundwater samples in the region can be used for irrigation purposes.•Three different pollution levels were present in hierarchical CA; low, moderate, and high polluted sites.