Assessment of water quality of Tigris River by using WQ index in Salah Al-Din province

The management of water resources depends on the evaluation of water quality. In this research, Water Quality Index (WQI) was used to evaluate Tigris River water quality for drinking water purposes and assess significant factors that affect water quality. The physiochemical parameters measurements of water samples taken from four sites along the river within Salah Al-Din province were collected from October 2022 to May 2023, including water temperature, turbidity, Electrical Conductivity (EC), Total dissolved Solids (TDS), pH, Dissolved Oxygen (DO), Biological oxygen demand (BOD5), Total harness, Calcium, Magnesium, Total Alkaline, Chloride, Sodium, Potassium, Sulfate, Nitrite, and Phosphate. The results of WQI values ranged from 71.28 to 90.78, the water was considered poor to very poor in the study sites, due to the water getting polluted to some extent, so the value of WQI decreases. This indicated the Tigris River in the study area was unsuitable for drinking uses.