Assessment of the Water Qualitative Characteristics of the Tigris River Passing Through the City of Mosul and Calculating the Water Quality Index Coefficient

The quality of the water of the TigrisRiver passing through the city of Mosul was studied, starting from the Kubba area in the north to the Yarmajah area in the south, and the TigrisRiver is the only water resource for the city. The Physical and Chemical propertiesof river water was conducted, which included (water temperature, pH, electrical conductivity, total dissolved solids, turbidity, dissolved oxygen and some positive and negative ions), and the Canadian Water Quality Index = (WQI) was used to express the quality of river water. Tigris as it passes in the city of Mosul. The results indicated that the water of the TigrisRiver passing through the city of Mosul tends towards alkalinity, and the river water has good ventilation, as the average dissolved oxygen values ranged between (8.3-9.3) mg / liter. The ions of nitrates, orthophosphates, sulphates and chlorides showed a variation in their concentrations during the study period. The rates of sodium and potassium ion concentrations ranged between (19.9-24.6) and (2.6-4.2) mg / liter, respectively. The studied water was classified as (good - moderate) for drinking, as the values of the water quality index ranged between (76.7-91.2). The index values ranged between (86.3-99.6) and the water was classified as excellent too good for the river conservation system.