The concerns about water contaminants affect most developing countries bypassing rivers over them. The issue is challenging to introduce water quality within the allowed limits for drinking, industrial and agricultural purposes. In the present study, physical-chemical parameters measurements of water samples taken from eleven stations were collected during six months in 2020 through flow path along the whole length of Tigris River inside AL Kut city (center of Wassit government) were investigated for six parameters are total hardness TH, hydrogen ion pH, biological oxygen demand BOD5, total dissolved solids TDS, nitrate NO3, and sulfate SO4. The water quality analysis results were compared with the maximum allowable limit concentration recommended by World Health Organization WHO and Iraqi limitation spastically; TH, BOD5, TDS, and SO4 had an average value of 421, 62, 813, and 376 mg/l, respectively. The spatial distribution of six water quality parameters within the studied area was carried out by implementing the Quantum Geography Information System QGIS technique established on the Inverse Distance Weighted IDW method to produce the interpolation predicted maps of stations along the river in Al Kut city. The results showed water quality degraded and an increase in the concentrations observed for all parameters along the river path, especially at the last two stations due to attributed to human activities, land use and industrialization, and outfall of sewerage flow to the river directly without treatment. Spatial distribution is essential to give a thorough understanding of the river's contamination reality. This makes it easier to understand, analyze and find the appropriate treatments and solutions to the problem of water quality.
