EVALUATE THE GROUNDWATER SUITABILITY FOR IRRIGATION IN DUJAILA AREA – WASIT GOVERNORATE – MIDDLE OF IRAQ

The selected area is Dujaila project, Wasit governorate, Iraq. Twelve water samples groundwater and drainage were collected during March 2016. Total dissolved solids (TDS), pH, electrical conductivity (EC), major ions Ca2+, Mg2+, Na+, K+, Cl-, SO4 2- and HCO3-, and chemical analysis were determined. To evaluate the suitability of analyzed water for irrigation, Sodium adsorption ratio (SAR), residual sodium carbonate (RSC), sodium percent (Na%) and electrical conductivity were applied. The based on electrical conductivity classification of the analyzed water indicated that both the groundwater and drainage water are unacceptable for irrigation, except for very salt-tolerant plants (EC> 2250 μs/cm). These samples mostly have no harmful effects and no hazard in terms of RSC (RSC < 0), while for SAR, the groundwater samples have no harmful effects of sodium (SAR < 10) but it is unsatisfactory for irrigation for drainage water samples ( SAR > 26) and groundwater samples are good (Na% range from 20 to 40) to permissible (Na% > 40) in terms of Na%, while, the drainage water samples indicate doubtful class for the three samples (Na% > 60). Applying the water-sediment relationship experiments with respect to dry and wet periods show that about 2.2% – 4.8% of the TDS were librated after the drying condition which is believed to be of the water-soluble salts that exist within the sediment column.