Groundwater is the foremost water source in the arid and semiarid regions of Northwest China. Assessing groundwater's drinking and irrigation quality is essential for protecting these valuable groundwater resources. In this study, a total of 24 confined groundwater samples and 54 phreatic groundwater samples were collected in the southern and central Ningxia area for hydrochemical analysis and quality assessment. The hydrochemical results revealed that hydrochemical types of phreatic and confined groundwater consistently belonged to Na-SO₄-Cl and Na-Mg-SO₄-Cl types. The driving forces of groundwater chemistry were determined by gypsum dissolution, silicate dissolution, and positive cation exchange for phreatic and confined aquifers. The entropy-weighted water quality index (EWQI) and irrigation water quality index (IWQI) showed that the drinking water quality and irrigation quality were better in phreatic groundwater than in confined groundwater due to the Neogene-Paleogene groundwater system recharge and strong evaporation. Measures such as controlling groundwater extraction and optimizing well placement need to be implemented. The achievements would be helpful for groundwater management and protection in agricultural areas under semi-arid and arid climates.

地下水是西北干旱半干旱地区最主要的水源。评估地下水的饮用和灌溉质量对于保护这些宝贵的地下水资源至关重要。本研究在宁夏南部和中部地区共采集了24个承压地下水样品和54个潜水地下水样品进行水化学分析和水质评价。水化学结果表明，潜水和承压地下水的水化学类型一致属于Na-SO ₄ -Cl和Na-Mg-SO ₄ -Cl类型。地下水化学的驱动力由石膏溶解、硅酸盐溶解以及潜水和承压含水层的正阳离子交换决定。熵权水质指数（EWQI）和灌溉水质指数（IWQI）表明，由于新近纪-古近纪地下水系统的补给和强烈的蒸发作用，潜水水质和灌溉水质优于承压地下水。需要采取控制地下水开采和优化井位等措施。该成果有助于半干旱和干旱气候下农区地下水的管理和保护。