Suitability and Evaluation of the Quality of Groundwater Used in Irrigation, Case of the Region of Oum El-Bouaghi (Northeast Algeria)

This study assesses the quality of groundwater for irrigation in the plains of Bir Chouhada, Souk Naamane, and Ouled Zouai, focusing on physico-chemical parameters including Electrical Conductivity (EC), Sodium Adsorption Ratio (SAR), sodium percentage (%Na), and chloride toxicity. Results show EC values ranging from 993 to 9,322 µS/cm, indicating poor to unsuitable water quality for irrigation in most wells. The SAR values vary between 8.86 and 43.6 meq/L, reflecting a high risk of soil sodification. The %Na ranges from 19.18% to 61.41%, with over 66% of samples exhibiting high mineralization. Using Richards classification, 58.78% of samples fall in the highly unsuitable C4S4 class, while Wilcox classification indicates 48.78% of dry season samples as unsuitable for irrigation. Seasonal variation shows slight quality improvement during the wet season, with good-quality water increasing from 4.87% (dry) to 7.31% (wet). Hydrochemical facies analysis identifies 46.34% of samples as calcic chloride type, linked to mineralization from gypsiferous formations. Spatial autocorrelation using Moran’s I reveals moderate positive clustering of SAR (0.21-0.27) and %Na (0.15-0.23), with stable patterns across seasons. Statistical analysis via ANOVA confirms the significance of the model with F=29.48 (p<0.000005) and explains 43% of variation in water quality parameters. These findings highlight the critical challenges of irrigation water quality in the region and underscore the need for integrated management strategies including the use of salt-tolerant crops and soil drainage improvements.