渭河和泾河流域浅层地下水水化学特征和控制因素

渭河和泾河流域是黄河流域的重要支流，了解这两个流域地下水的水质状况对于黄河流域生态保护和高质量发展具有重要意义.本文利用Piper图、Gibbs模型、Na端元图和离子相关关系等方法，解释了两流域地下水水化学组成特征及其控制因素的特征与差异.并利用WQI法、Wilcox图、USSL图和Doneen图等方法，评估研究区地下水水质的饮用和灌溉适宜性.结果表明，渭河和泾河流域浅层地下水均以淡水为主，呈弱碱性；除Na⁺外，渭河流域地下水离子浓度整体上均大于泾河流域；两流域优势阴阳离子均为HCO₃^-和Na⁺；渭河流域水化学类型以HCO₃-Ca-Mg为主，占50%，而泾河流域以HCO₃-Ca-Mg和HCO₃-Na-K为主，各占32.5%.渭河和泾河流域水化学组成均主要受岩石风化作用控制，其中又以硅酸盐岩石风化为主；其次，研究区地下水水化学组成受到工矿活动的影响，且农业活动中化肥的施用也是其重要的控制因素；此外，渭河流域的浅层地下水水化学特征受到了明显的阳离子交替吸附作用的影响，而泾河流域有些地区却并不明显.对于饮用水水质评价而言，两流域地下水水质整体较好，且泾河流域地下水整体上优于渭河流域；根据SSP、SAR和PI指标对地下水作为灌溉水水质评价表明，研究区部分地区地下水不能直接进行灌溉，否则会造成盐害进而引起抑制植物生长，南部的水质优于北部；此外，3种灌溉水质评判方法均表明泾河流域地下水作为灌溉水水质整体上优于渭河流域.本研究能对渭河和泾河流域地下水水资源可持续利用、科学开发治理提供依据，并为黄土高原主要流域和其他类似地区水质管理及评价提供借鉴.

Hydrochemistry and Its Controlling Factors and Water Quality Assessment of Shallow Groundwater in the Weihe and Jinghe River Catchments

The Weihe and Jinghe Rivers catchments are important tributaries of the Yellow River, where it is of great significance to evaluate groundwater hydrochemistry and quality for ecological protection and sustainable development. Piper diagrams, Gibbs, Na-normalized molar ratios, and ion correlation methods were used to analyze the chemical composition of groundwater in these two catchments. Furthermore, the WQI method, Wilcox diagrams, USSL diagrams, and Doneen diagrams were used to evaluate the suitability of groundwater quality for drinking and irrigation. The results showed that the Weihe and Jinghe River catchments are dominated by fresh and weakly alkaline water. Groundwater ion concentration in the Weihe River are higher than in Jinghe River except for Na⁺, and the major groundwater types are HCO₃-Ca-Mg(accounted for 50%), and HCO₃-Ca-Mg and HCO₃-Na-K (accounted for 32.5%), respectively. The hydrochemistry of the Weihe and Jinghe River catchments is mainly controlled by rock weathering, primarily silicate weathering. Moreover, the groundwater chemistry in the research area is affected by mining and chemical fertilizer application for agriculture. Furthermore, the hydrochemistry of the Weihe River catchment is affected by cation exchange, although this was not obvious in some regions of the Jinghe River catchment. The overall groundwater quality of the two catchments was good, with the Jinghe River water quality being better than in the Weihe River catchment. Based on SSP, SAR, and PI, the groundwater in some parts of the study area cannot be directly used for irrigation as this would result in salinization and, thus, inhibit plant growth. Overall, the groundwater quality in the south of the study area is better than in the north, and is better in the Jinghe River catchment than in the Weihe River catchment according to these three indicators. This study provides a basis for the sustainable development of two catchments, providing baseline data for groundwater quality management.