摘要:The groundwater quality of wadi Jazan (southwest Saudi Arabia) experienced degradation due to rapid urbanization and industrialization. On the basis of the groundwater chemistry, an evaluation of groundwater for domestic and irrigation uses is established. Thirty one groundwater samples were collected in February 2011 from wadi Jazan, southwest Saudi Arabia to study the chemical parameters such as hydrogen ion concentration, total dissolved solids, electrical conductivity, total hardness, calcium, magnesium, sodium, potassium, bicarbonate, sulfate and chloride. To classify water quality for irrigation, parameters such as sodium adsorption ratio and sodium percentage were calculated. Concentrations of major cations and anions of groundwater samples are exceeding the allowable concentration compared to their levels in potable water. The total dissolved solids are 5220 mg/l or below which indicates the presence of saline water. The saline water condition is also verified by low to high electrical conductivity (552 to 8030 mS/cm) and lowers than 7.92 hydrogen ion concentration values. The low to medium sodium adsorption ratio (0.99 to 10.62) coupled with low to high electrical conductivity gives the water medium, high to very high salinity hazard and low to medium sodium hazard. Thus, most of the study groundwater samples are generally unsuitable for domestic and irrigation purpose.