Ningxia Survey and Monitoring Institute of Land and Resources, Yinchuan 750000, China.
Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
J Contam Hydrol. 2023 Nov;259:104256. doi: 10.1016/j.jconhyd.2023.104256. Epub 2023 Oct 15.
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-SO-Cl and Na-Mg-SO-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.
地下水是中国西北干旱半干旱地区的首要水源。评估地下水的饮用水和灌溉水质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 个承压水样本和 54 个潜水样本，进行了水化学分析和质量评估。水化学结果表明，潜水和承压水的水化学类型均属于 Na-SO-Cl 和 Na-Mg-SO-Cl 型。地下水化学的驱动力是石膏溶解、硅酸盐溶解和正阳离子交换，对潜水和承压含水层都有影响。熵权水质指数（EWQI）和灌溉水质指数（IWQI）表明，由于新近纪-古近纪地下水系统补给和强烈蒸发，潜水的饮用水水质和灌溉水质要好于承压水。需要采取控制地下水开采和优化井位等措施。这些成果将有助于半干旱和干旱气候条件下农业区的地下水管理和保护。
