Water Quality Assessment of the Euphrates River from Haditha to Al-Nasiriyah, Iraq

A comprehensive assessment of four gauging stations along the Euphrates River reach (Haditha, Al-Hindiya, Samawa, and Al-Nasiriyah) was conducted to assess the water quality deterioration spatially and temporarily for the period 2005-2021. The spotlight is on discharge rates and climate conditions, which mainly controlling water quality and availability. The mean monthly discharge rate was taken 2005–2021, in addition to the water quality parameters (TDS, pH, EC, Mg+2, Ca+2, Na+, SO4-2, Cl-, and HCO3-, BOD5, COD, FCB, and E. coli). The discharge rates showed a visible decrease downstream, causing the river salinity and all the ion concentrations to rise. The statistical package of social sciences revealed two groups of water pollution sources: The F1 reflects natural conditions produced from the dissolution of the basin rocks, with a percentage of 28.0% from the total variance; the eigenvalue is 4.4. F2 reflects the anthropogenic sources, contributing 14.5% and having an eigenvalue of 2.1. The total ionic salinity plot indicated less than 2000 mg/l at the Haditha and Al-Hindiya sites and between 3000 and 4000 mg/l at downstream sites (Samawa and Al-Nasiriyah). The transportation of dissolved loads is decreased downstream following the discharge rate as indicated by the rating curves, as follows: 781000, 542628.4, 443861, and 432950.4 tons/month for Haditha, Al-Hindiya, Samawa, and Al-Nasiriyah, respectively. Water type shows a notable downstream deterioration, from MgSO4 at Haditha and Na2SO4 at Al-Hindiya to NaCl at Samawa and Al-Nasiriyah sites.