Assessment of water quality for Zar Gali stream, Bekhal (Maran)‎ and Khalan rivers within Erbil, Iraq

الملخص EN

This study was conducted to characterize the water quality of Bekhal (Maran) River, Zar Gali stream and Khalan Rivers, based on the Water Quality Index (WQI) calculation method.

Water samples from three sampling stations sampled from April until November 2014.

The three sites are situated within Soran district, Kurdistan Region of Iraq marked as Bekhal (Maran) River (Site 1), Zar Gali Stream (Site 2) and Khalan River (Site 3).

Surface water samples were taken at each site for eighteen physical and chemical parameters; turbidity, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), pH, Electrical Conductivity (EC), Total dissolved Solid (TDS), alkalinity, total hardness, calcium ion (Ca2+), magnesium ion (Mg2+), sodium (Na+), potassium (K+), chloride (Cl-), nitrite (NO2-), nitrate (NO3-), Sulphate (SO42-), Sodium percent (Na%) and Sodium Adsorption Ratio (SAR).

Drinking WQI was calculated based on the six parameters.

However, Irrigation Water Quality Index (IWQI) was calculated based on twelve parameters.

On the basis of the WQI for the drinking purpose, the quality of the water is categorized from good to poor.

The water quality status of Maran River (sites 1) was 142.9 and Khalan River (site 3) was 96.22 both sites fall under poor category, while the site 2 (Zar Gali Stream) was 143 and it falls under good category.

On other hand, based on EC, the IWQI may classify the waters as excellent for irrigation purpose.