The effect of water imports and tidal movement on the hydrochemical properties of the Shatt al-Arab.

A field study was conducted on the course of the Shatt al-Arab for the period from September 2021 to August 2022. to track the space-time changes in the quality of moving water in the course of the Shatt al-Arab under the influence of the movement of tidal cycles and their interference with fresh water coming from the Tigris River. through four study stations located in the areas of Al-Sada Al-Nour, the paper factory, Al-Ashar, and Sehan. and the study aimed to find out the extent of variation in the values of salinity. the concentration of dissolved solids and concentrations of some Cations and anions spatially and temporally and the extent to which they are affected by the movement of tides. Aquatic samples were collected from the study stations according to the four seasons of the study period and from three depths and three repeats from each depth. The results of the statistical analysis showed significant differences in the values of all studied vocabulary, namely EC, pH, Ca + 2, Mg+2, TH, Na + 1, HCO3-1, Cl-1, SO4-2 based on the stations and seasons studied, and the values of the studied vocabulary showed a spatial and temporal variation, as the salinity values increased as we headed south towards the mouth of the river and the ranges of values reached 1.92-8.45 dS-1.The pH values tended to be light basal and ranged between 7.79 – 8.06, and the concentrations of cations and anions varied spatially and temporally as they were affected by the movement of the tides and the values of the concentrations ranged between 116.43 - 661.67, 35.16 -147.62, 167.67 - 1118.91, 221.43-2337.53 and 344.88 - 1073.68 mg L-1 for ions Ca+2, Mg+2, Na+1, Cl-1, SO4-2 respectively.