Assessment of groundwater quality for agricultural irrigation in the Al-Tawila Area, West of Sabratha, Libya

Abstract

Background: Groundwater is a vital natural resource that supports drinking, domestic, and agricultural activities, particularly in arid and semi-arid regions. Aim: This study aimed to evaluate the physicochemical characteristics and irrigation suitability of groundwater in the Al-Tawila area, west of Sabratha, Libya. Methods: Groundwater samples were collected from ten wells in August 2022 and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), major ions, and total hardness (TH). Irrigation suitability was assessed using the sodium adsorption ratio (SAR), sodium percentage (Na%), United States Salinity Laboratory (USSL) classification, and Wilcox classification. Results: The pH ranged from 6.20 to 7.17, EC from 1.687 to 7.018 mS/cm, and TDS from 1079.7 to 4701.8 mg/L. Sodium (Na⁺) was the dominant cation, while TH ranged from 200 to 500 mg/L. Most samples were classified as C3–S1 or C4–S1, indicating high to very high salinity with low sodium hazard. The Wilcox classification identified several samples as doubtful to unsuitable for irrigation. Conclusion: Groundwater in the Al-Tawila area may be used to irrigate salt-tolerant crops when appropriate irrigation, drainage, leaching, and salinity-monitoring practices are implemented to reduce soil salinization and maintain long-term productivity.