三峡水库典型支流水化学变化特征及成因分析OA
Characteristics and Causes of Water Chemistry in Typical Tributaries of the Three Gorges Reservoir
为探究三峡库区支流库湾水体水化学变化特征及干流回水对支流库湾水化学的影响,2022年4月对三峡水库小江、大宁河、香溪河三条典型支流库湾进行了采样及分析.结果表明,三条支流库湾优势阴、阳离子分别为HCO3-、Ca2+,其中HCO3-质量浓度均值分别为155.50、152.20和171.50mg·L-1,占总阴离子质量浓度的67%、93%和95%;Ca2+质量浓度均值分别为34.70、49.40和47.00mg·L-1,占总阳离子质量浓度的58%、61%和60%.小江、香溪河库湾水化学类型为HCO3--Ca2+,大宁河库湾水化学类型为HCO3-·SO42--Ca2+.Gibbs图与端元图的结果显示,岩石风化主导的碳酸盐岩溶解是控制水化学的主要机制,但大宁河流域蒸发盐岩强度较高且大于小江与香溪河,加之大宁河有小三峡景区,存在较大的人类活动干扰,导致其Cl-质量浓度(26.60mg·L-1)是小江(2.90mg·L-1)和香溪河(2.00mg·L-1)库湾的9～12倍.采用保守离子(如Cl-和Na+)示踪法估算贡献率,小江、大宁河、香溪河三条支流库湾回水区的干流来水贡献率分别约为49.0%、70.5%、71.9%,干流回水对三条支流库湾的影响与距离三峡大坝远近以及支流流量有关,而支流库湾的补给与稀释程度取决于干支流来水的物质差异与水团大小.
In order to explore the characteristics of hydrochemical changes in the tributaries of the Three Gorges Reservoir area and the influence of the backwater of the main stream on the hydrochemistry of the tributary reservoir bays,the reservoir bays of the three typical tributaries of the Three Gorges Reservoir were sampled and analyzed in April 2022.The results showed that the dominant anions and cations in the three tributaries were HCO3-and Ca2+.The average concentration of HCO3-was 155.50 mg·L-1,152.20 mg·L-1,and 171.50 mg·L-1,accounting for 67%,93%and 95%of the total anion content respectively.The mean concentrations of Ca2+were 34.70 mg·L-1,49.40 mg·L-1,and 47.00 mg·L-1,accounting for 58%,61%and 60%of the total cationic content respectively.The hydrochemical type of Xiaojiang and Xiangxi River reservoir bays was HCO3--Ca2+,while the hydrochemical type of Daning River reservoir bays was HCO3-·SO42--Ca2+.The results of Gibbs diagram and end member diagram showed that the dissolution of carbonate rocks dominated by rock weathering was the main mechanism controlling water chemistry.Since the intensity of evaporate of salt rocks in the Daning River basin was higher than those of Xiaojiang and Xiangxi river,and there existed a scenic spot of small Three Gorges in Daning River with significant disturbance of human activities,the concentration of Cl-(26.60 mg·L-1)was 9～12 times higher than that in the reservoir bays of Xiaojiang(2.90 mg·L-1)and Xiangxi River(2.00 mg·L-1).By the conservative ion(such as Cl-and Na+)tracer method,the contribution rates in the backwater area of the three tributaries of Xiaojiang,Daning River and Xiangxi River were about 49.0%,70.5%and 71.9%,respectively.The influence of the main stream backwater on the reservoir bay of the three tributaries was related to the distance from the Three Gorges Dam and the flow of the tributaries,and the recharge and dilution degree of the tributary reservoir bay depended on the material difference and the size of the water mass from the main and tributaries.
杨紫剑;刘佳;肖尚斌;朱良辰;陈敏;康满春;李世剑;高婷
三峡库区生态环境教育部工程研究中心,湖北 宜昌 443002三峡大学 水利与环境学院,湖北 宜昌 443002三峡库区生态环境教育部工程研究中心,湖北 宜昌 443002三峡大学 水利与环境学院,湖北 宜昌 443002三峡库区生态环境教育部工程研究中心,湖北 宜昌 443002三峡大学 水利与环境学院,湖北 宜昌 443002三峡库区生态环境教育部工程研究中心,湖北 宜昌 443002三峡大学 水利与环境学院,湖北 宜昌 443002
资源环境
三峡水库离子浓度离子来源贡献率回水区
Three Gorges Reservoirion concentrationion sourcecontribution ratebackwater area
《三峡大学学报（自然科学版）》 2026 (1)
32-40,9
国家自然科学基金项目(52130903)
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