Study of the quality and validity of the water of the River Tigris (Al-Gharraf stream) within the city of Nasiriya- Iraq

Despite the importance of water for life, drinking, irrigation, power generation and industrial use. This study concerns the study of the quality and validity of water by applying the arithmetic weight index (AWI) for the water quality of irrigation , where the selection of the eleven variables acidity (PH), Total Dissolved Solid (T.D.S), Alkalinity(ALK), Electrical Conductivity (E.C), Calcium(Ca), Chloride (CL), Sodium (Na), Sulfate (SO4), Potassium (k), Total suspended solids (T.S.S), Total hardness (TH) to show the water quality of the study area. The water samples collected from the river were examined and numbered 17 for two seasons. The study reveals that the water quality index has increased along the stream which indicates the water is completely unfit for irrigation use(arithmetic weight rating almost stations were between poor and very poor water). civilizations around this stream are probably lead to degrading water quality, which could be a menace to the public.