石羊河流域地下水中硫酸盐的水文地球化学特征及来源

Hydrogeochemical Characteristics and Sources of Sulphate in Groundwater of Shiyang River Basin

为解决石羊河流域土地沙漠化和水资源短缺等问题,发挥地下水对地表生态的支撑作用,通过采集流域泉水、地表水和地下水样品,研究其水化学和硫酸盐硫氧同位素的组成和来源,揭示流域地下水演化规律,支撑地下水的合理开发利用。结果表明,石羊河流域各类水体^(δ34)S_(SO_(4))与^(δ18)O_(SO_(4))整体偏低,大部分分布在大气降水和硫化物区域,离蒸发岩溶解端元较远,指示出武威盆地和民勤盆地地下水主要受到大气降水和硫化物氧化溶解控制,SO_(4)^(2-)主要来源于二者,蒸发岩的溶解对下水影响较小,为判识SO_(4)^(2-)的来源、迁移和转化提供线索,为分析地下水循环规律提供有力帮助。

In order to solve the problems of land desertification and water resources shortage in Shiyang River Basin,and play the support function of underground water on earth surface ecology,the study collects the samples of drainage basin spring water,surface water and underground water;researches the composition and sources of chemical and sulfur and oxygen isotopes of sulfate;and reveals the evolution law of underground water of the basin,to support the rational development and utilization of underground water.The results show that^(δ34)S_(SO_(4)) and^(δ18)O_(SO_(4)) of various kinds of water in Shiyang River Basin is generally low,which mainly distribute in meteoric water and sulfide regions,and are far from evaporative karst end member.It is pointed out that the underground water of Wuwei and Minqin Basin is mainly influenced by meteoric water and oxidation solution of sulfide,and SO_(4)^(2-)mainly comes from the two.The dissolution of the evaporite has little influence on underground water,provides clue for the source,migration and conversion SO_(4)^(2-),and provides strong help for the analysis of underground water circulation law.