Abstract
A comprehensive assessment was applied to assess the chemical characteristics of a fresh to saline groundwater resource and its hydrogeological setting in the Al-Lusub basin, Western Saudi Arabia. The assessment was undertaken using drinking water suitability zone (DWSZ) maps, irrigation water quality indices (IWQI), and irrigation water quality parameters. The assessment indicated that groundwater in the region is mostly brackish (71%, n=52) and alkaline in nature. The spatial distribution of electrical conductivity (EC), total dissolved solids, major cations, Cl-, and SO42- is influenced by the groundwater flow direction. The DWSZ maps suggest that the groundwater is not suitable for drinking without proper treatment. According to sodium adsorption ratio, Kelly's ratio, Na%, EC, and bicarbonate hazard, 63%, 46%, 69%, 65%, and 92% of the wells, respectively, are unsuitable for irrigation. To eliminate these variations, IWQI were determined, which indicated that 75% wells have "low" suitability for irrigation use (IWQI<22), while the remaining wells were classified as being "moderately suitable" for irrigation. Furthermore, groundwater is suitable only for salt-tolerant crops and soil with good drainage and permeability. Besides, only 22% of wells are usable for livestock and poultry farming due to high salinity and nitrate. The DWSZ and IWQI maps help to determine suitable places for groundwater development and management. This work concluded that comprehensive assessment of groundwater quality in any aquifer would help for proper management and planning for future water need.